All posts by SETAC Student Outreach

Simplifying ecotoxicology studies with model species: Are organisms in the North hemisphere the same as the organisms from the South?

By Fernando Gastón, Iturburu* and Lidwina, Bertrand*.

Endings are a great opportunity to reflect on past decisions. As both of us wrap up our PhDs in Ecotoxicology (Fernando at the National University of Mar del Plata and Lidwina at the National University of Córdoba, both in Argentina), we keep thinking of the questions we struggled with as students and the conclusions we reached. One of the biggest questions in our research was: is it better to work with native species or model organisms to examine research questions pertaining to aquatic environments in South America?


Model organisms are simple organisms expected to behave similarly to other organisms when exposed to potentially harmful chemicals. Traditional model species include zebrafish (Danio rerio), aquatic macrophytes of the Myriophyllum and Lemna genera and planktonic crustacean as Daphnia magna among others (Häder and Erzinger, 2018). Model species are well studied, so a lot is known about how to keep them happy and healthy in a laboratory setting. But, most benchmark testing for model organisms was developed in the northern hemisphere, particularly more socio-economically developed countries like the USA, China, Germany, UK, and Canada. Since different species are known to have different sensitivities to toxic compounds (Van der Oost et al., 2003), it is questionable whether or not model organisms can act as representative samples for environmental studies concerning environments in the southern hemisphere.

Our research was concerned with conducting experiments to understand the potential negative impacts of metals and pesticides on South American, particularly Argentinian, aquatic ecosystems. These chemicals can enter the environment from industrial activities such as metalworking, tanneries, litter bins, open sky mega-mining with tons of rocks extracted each year, and large- scale agricultural production which are all common throughout South America. We had several questions while designing our research experiments:

1- Are native species useful (like model ones) to assess environmental degradation through biomonitoring programs?

2- Are studies carried out using species from European or North American countries representative of the sensitivity of species present in ecosystems from others regions of the world?

3- Are the established guidelines developed with model organisms “good” enough to protect species from South American ecosystems?

4- Could we develop our own guidelines with native species?

We were ultimately swayed to using multiple local species (shown in Figures 1 and 2) because we believe, along with the experts of the OECD (Organization for Economic Co-operation and Development, 2002), that multiple indigenous test species provide more robust results for resolving regional environmental concerns.  But this decision came with several advantages and disadvantages. Let’s start with the “worst” part of the story, the disadvantages of working with native species:

– The first problem is the absence or low availability of basic information about your object of study. Since no one else is studying them, there’s a lot more uncertainty in understanding how chemicals affect them. There is also little information about how to keep them healthy in a laboratory setting so it is hard to say if observations are caused by chemicals or just abnormal living conditions. Resolving this concern involves a lot of time, money, and resources (which are sparse when you’re a PhD student!) which can limit your experimental design and, sometimes, lead to make mistakes or to obtain non “suitable” results.

– Other problem arise when you try to publish your first paper and reviewer’s comments arrive in your inbox. Comments reflect great distrust in your results, even if standardized protocols were applied, because you are not using a model species. This leads some reviewers to doubt the usefulness of your research because is not a world recognized model and concern.



Figure 1- Australoheros facetus is a cichlid fish which inhabits the Parana’s basin in Brazil, Paraguay, Argentina, and Uruguay. It is a suitable and sensitive fish species to assess pesticides pollution in South American ecosystems. Ph: Fernando G. Iturburu.

But not everything is negative when you chose a native species to join you and your Ph.D. thesis for three or five years. Several advantages to using native species are:

– Usually, the “native” characteristic allows for better availability and accessibility to organisms for experimental tests. They don’t have to be shipped too far, and could even be collected close to your lab!

– You can avoid the introduction of exotic organisms into local waters when conducting field studies with foreign model organisms, which has the potential to cause serious ecosystems disorders.

– The lack of information about native species can also be considered a positive: ALL is new and the obtained information will improve the understanding of the sensitivity of these species and related ones, and how regional ecosystems would be affected in presence of pollutants. New biological mechanisms and responses can be found and published but, again, tips about how to communicate your research work are crucial! You must convince reviewers that non-model species results represent a novelty important for advancing global ecotoxicological knowledge.

– Results from native species studies would be considered for the selection of new, region-specific model species to use in the establishment of environmental guidelines of studied region, which could improve the protection of aquatic ecosystems.

When comparing results from our research to the existing body of literature, we found the advantages to outweigh the disadvantages. The literature describes that the LC50 (concentration at which 50 percent of organisms in a study exposed to a compound die) for the neonicotinoid insecticide imidacloprid in model fish is around 200 mg L-1 (IUPAC PPDB, 2018). Nevertheless, for the South American cichlid fish Australoheros facetus (Figure 1), we found that the LC50 value was much less: below of 10 mg L-1 (Iturburu et al., 2017)! Even more, this compound causes DNA damage from concentrations of 1 μg L-1 (Iturburu et al., 2018, remember that 1 microgram (μg) is a millionth part of 1 gram).

Figure 2- Palaemonetes argentinus represents a small decapod from water ecosystems of South America. Its sensitivity to pollutants exposure as well as its ecological relevance in trophic chains and, ecosystems, led to it being proposed as a possible bioindicator of environmental quality. Ph: Lidwina Bertrand.

We also found interesting results with respect to variability in sensitivity across organisms. For example, the Argentinean Environmental Water Quality Guidelines (AEWQG, 2003) recommends concentrations of the widely used insecticide chlorpyrifos (CPF) should not exceed 6 ng L−1 (being 1 nanogram, ng, a billionth part of one gram) for the protection of aquatic biota. This limit comes from experimental results with model species from others world regions. Nevertheless, the shrimp Palaemonetes argentinus (Figure 2) and the macrophyte Potamogeton pusillus showed significant response of studied biomarkers after 96hs of exposure at 3.5 ng L−1! In the case of the shrimp, several biomarkers responded significantly at 3.5 ng L−1 CPF, including metallothionein concentration (decreased), acetylcholinesterase (inhibited) and antioxidants enzymes (induced) activities; while in the macrophyte chlorophylls contents dropped in described conditions (Bertrand et al., 2016 and 2017). Usefulness of native species as bioindicators of water pollution was evidenced using them in river monitoring campaigns (Bertrand et al., 2018 a, b).  So, all these results (and many others) which show that different species can still be affected at different concentrations of a chemical, even below an accepted limit, telling us that species selection in ecotoxicology testing is very important.

Thus, the native species have a lot of information to bring us, and from our place (and with all necessary considerations) we will continue to promote the use of these organisms to understand the possible effects of pollution in South American and others ecosystems. And maybe one day (who knows!), we will be able to have our own model species and guidelines.



Blogpic-5Iturburu, Fernando Gastón obtained his Ph.D. in Biological Sciences at the National University of Mar del Plata, Argentina. His research focused on the effects of current use pesticides on two South American freshwater species: a cichlid fish (Australoheros facetus) and a macrophyte (Myriophyllum quitense). The thesis aimed to study different biomarkers of these organisms experimentally exposed to pesticides, as well as study factors which could modify the interpretation of these responses. As an ultimate goal, the project aimed to establish these organisms as freshwater bioindicators in South American aquatic ecosystems. Publications from PhD thesis can be found in:



Blogpic-6Bertrand, Lidwina obtained her Ph.D. in Biological Sciences at the National University of Córdoba, Argentina. Her research focused on the usefulness of two South American native species, a small shrimp (Palaemonetes argentinus) and a rooted macrophyte (Potamogeton pusillus), as freshwater bioindicators. The thesis involved firstly the study of biomarkers responses in mentioned organisms exposed to environmentally relevant concentrations of pollutants (metal and pesticide) laboratory conditions. Experiments involved exposure concentrations lower than those suggested by Argentinean environmental guidelines. Finally, organisms were used in an active monitoring with the aim to analyze their sensitivity in sites with complex mixture of pollutants associated with different land uses in the Ctalamochita River Basin as a case of study.  Publications from PhD thesis can be found in:




– AEWQG (Argentinean Environmental Water Quality Guidelines), 2003. Subsecretaria de Recursos Hídricos de la Nación, República Argentina.

– Bertrand, L., Monferrán, M.V., Mouneyrac, C., Bonansea, R.I., Asis, R., Amé, M.V., 2016. Aquat. Toxicol. 179, 72–81.

– Bertrand, L., Marino, D.J., Monferrán, M.V., Amé, M.V., 2017. Environ. Exp. Bot. 138, 139–147.

– Bertrand, L., Monferrán, M.V., Mouneyrac, C., Amé, M.V., 2018a. Chemosph. 206, 265–277. https://doi:10.1016/j.chemosphere.2018.05.002

– Bertrand, L., Monferrán, M.V., Valdés, M. E., Amé, M.V., 2018b. Env. And Exp. Bot. Under revision.

– Häder, D. P. and Erzinger, G. S., 2018.  Bioassays: Advanced Methods and Applications. Elsevier.

– Iturburu, F.G., Zömisch, M., Panzeri, A.M., Crupkin, A.C., Contardo-Jara, V., Pflugmacher, S., Menone, M.L., 2017. Ecotoxicol. Toxicol. Chem. 36(3), 699-708.

– Iturburu, F.G., Simoniello, M.F., Medici, S., Panzeri, A.M., Menone, M.L., 2018. Bull. Environ. Contam. Toxicol.

– International Union of Pure and Applied Chemistry (IUPAC). PPDB: Pesticides Properties DataBase. University of Hertforshire, Hatfield, Hertfordshire, UK. [cited 2018 April 19]. Available from:

– OECD (Organization for Economic Co-operation and Development). Testing guidelines. Available from:

– van der Oost, R., Beyer, J., Vermeulen, N.P.E., 2003. Environ. Toxicol. Pharmacol. 13, 57–149,


Why we Need a Science-Based Approach to Help the Monarch Butterflies

By Niranjana Krishnan

I will start by acknowledging this: I am lucky to be working with monarch butterflies. Not only are they fascinating and beautiful, very few labs in the country have colonies to run year-round bioassays. At Iowa State University, where I am a PhD student, the colonies are maintained by the U.S. Department of Agriculture (USDA).

monarch butterflies
USDA’s monarch butterfly colony in Ames, Iowa

There are several factors that make monarchs captivating species: their four-stage life cycle, their annual passage across North America, their reproductive diapause (i.e., suspension of mating) before migration to overwintering sites, and so on. As you can find all this information easily online, I will stick to something which isn’t written or published anywhere (yet!): my research. I assess the risks of insecticide exposure on monarch butterfly larvae. Before I delve more into this exciting work, I would like to explain why it is important and what can be achieved with this research.

In the US you see two major migratory populations, one to the east of the Rocky Mountains and the other to the west. Both populations have declined by nearly 80% in the last two decades¹. In response to this, U.S. Fish and Wildlife Service (USFWS) was petitioned to list the monarchs as endangered species. The agency will come up with a listing decision in June 2019², but in the meantime released a working document that stressed the need to know risks of insecticide exposure on the butterfly³. The decline also made then President Obama specifically include monarch butterflies in his Pollinator Memorandum, where he tasked the U.S. Environmental Protection Agency (USEPA) and USDA to restore their populations⁴. One of the major reasons for the butterfly decline is believed to be the loss of milkweed⁵- the only food the caterpillars eat. Thus, conservation efforts are focused on planting milkweeds, especially in Iowa and the neighboring Midwestern states, which form the summer breeding grounds of the eastern monarch migratory population. As these states also have large swaths of land devoted to agriculture where insecticides are often used, there is a concern that planting milkweeds in such landscapes could negatively impact larval survival and adult recruitment. Because of this concern, USDA issued a guideline discouraging milkweed establishment within 125 feet of insecticide-treated crop fields⁶. For a representative county in Iowa, we found that this ‘no plant zone’ would exclude over 80% of rural roadside rights-of-ways and nearly 40% of non-crop lands. That is a lot of area being lost where potential habitat could go. And unfortunately, there is very little monarch toxicology or exposure data to know at what distances to plant milkweeds away from insecticide-treated fields.

And that’s what my lab is trying to find out! We selected insecticides commonly used in corn and soybean fields, as they are the predominant crops grown in the midwestern states. Our six representative insecticides cover four different groups based on modes of action: pyrethroid, organophosphate, neonicotinoid and anthranilic diamide. In corn and soybean fields, these insecticides are either sprayed or coated on the seeds. If they are sprayed, they can drift and land on nearby milkweeds or larvae. If they are coated on seeds, they can leach into the soil and be absorbed by milkweeds downslope of the crop field. Thus larvae can be either directly exposed to insecticides through their cuticle or indirectly exposed by consumption of milkweed leaves. Our toxicology bioassays mimic these two routes of exposure.

To figure out at what distances to plant milkweeds from crop fields, we are doing the following:

  1. Determining the toxicity of insecticides on the larvae by generating dose-response curves, i.e., finding concentrations that cause a spectrum of mortality (0% to 100%).
  2. Estimating exposure concentrations that the larvae are likely to face at different distances from treated fields (the further away they are, insecticide exposure will decrease). We rely on computer models and field studies to obtain this information.
  3. Using the dose-response curves and exposure estimates to calculate larval percentage mortality at different distances away from the field. This is called a patch-scale risk assessment.
  4. Incorporating the above information into an agent-based model⁷ to see how the monarch population responds at the landscape level. This is called a landscape-scale risk assessment and it is more realistic and informative than a patch-scale risk assessment since monarch butterflies fly across the landscape and lay one or two eggs on milkweed stems here and there. They don’t lay all their eggs in one basket!

The final step can help answer questions like how many monarchs would be produced with and without a ‘no plant zone’ (125 feet or otherwise) over a ten-year period in Iowa. Based on our data, the habitat placement option that produces the most monarchs can hopefully be implemented on the ground.

So far, we have obtained comprehensive results for spray applications where the insecticide directly lands on larvae. Based on our toxicology studies, pyrethroid (beta-cyfluthrin) and anthranilic diamide (chlorantraniliprole) insecticides cause the greatest mortality, followed by organophosphates (chlorpyrifos). Neonicotinoids (imidacloprid and thiamethoxam) cause negligible mortality, especially to older larvae. The larval mortality away from the field is much greater if the insecticide is applied via an aircraft as compared to ground applications⁸. Based on our landscape modeling data so far, more adult monarchs are produced by planting milkweeds in all available space as compared to scenarios with 125 feet ‘no plant zone’ around corn and soybean fields, even with the larval mortality due to spray drift⁹. Our ongoing studies are looking at how larval consumption of milkweeds that contain insecticides can influence monarch production and inform options for placement of new habitat.



Niranjana Krishnan is obtaining a doctorate degree in toxicology from the entomology department at Iowa State University. She is a student member of Iowa Monarch Conservation Consortium (



  1. Brower L.P., Taylor O.R., Williams E.H., et al (2012) Decline of monarch butterflies overwintering in Mexico: Is the migratory phenomenn at risk? Insect Conserv Divers 5:95–100.
  5. Flockhart DTT, Pichancourt JB, Norris DR, Martin TG (2015) Unravelling the annual cycle in a migratory animal: Breeding-season habitat loss drives population declines of monarch butterflies. J Anim Ecol 84:155–165. doi: 10.1111/1365-2656.12253
  6. National Resources Conservation Service (NRCS) Monarch Butterfly Wildlife Habitat Evaluation Guide (2016)
  7. Grant T., Parry, H., R., Zalucki, M.J., and Bradbury, S.P. (2017) Predicting monarch butterfly movement and egg laying with a spatially-explicit agent-based model: The role of monarch perceptual range and spatial memory. Ecological Modelling (Submitted).
  8. Krishnan, N., Bidne, K., Hellmich, R., Coats, J. and Bradbury, S.P. (2017) Risk assessment of insecticides commonly used in corn and soybean production on monarch butterfly (Danaus plexippus) larvae.  Society of Environmental Toxicology and Chemistry North America 38th Annual Meeting. November 12 -16, Minneapolis, MN (Abstract ID# TP106).
  9. Bradbury S.P., Grant, T.J., Krishnan, N. (2017) Landscape Scale Estimates of Monarch Butterfly (Danaus plexippus) Population Responses to Insecticide Exposure in an Iowa Agroecosystem. Society of Environmental Toxicology and Chemistry North America 38th Annual Meeting. November 12 -16, Minneapolis, MN (Abstract ID# 182).


The Arctic was not what I expected

By Neal Bailey

I was surprised from the moment I stepped off the bush plane. No exposed rock, snow, or cold winds. Instead, a sunny and warm stretch of flat, mossy soil extended to a low crest of hills ahead. There were a handful of fuel barrels placed strategically across the landscape as markers – an attempt to impose some sort of border on the landscape. There was a cabin – Green Cabin; a single room with a table, some supplies, and a small camp oven. Everything else was the Arctic summer- the blaze of a sun that swung overhead in a perpetual arc. I hadn’t read that it would be hot. I had, however, read about the mosquitos. They saw us, correctly, as their only chance for blood, and I applaud their persistence. Persistence, in the Arctic, is key.


Banks Island – Location of the Thomsen River


Aulavik sees few visitors; in a typical year, perhaps a dozen people set foot there. Usually, these few are either Parks Canada employees on a survey, or people looking for a chance to canoe up the most northerly navigable river in North America. The costs and conditions involved are both forbidding – planes need to be specially chartered, supplies need to be carried, and the terrain is vast and almost playfully unfriendly. The sheer isolation of the place is what makes it interesting to a scientist; here we have a corner of the world almost as far from human impacts as possible, and yet still the shadows of our influence loom. Each year, the winter grows softer and the summer season longer. The northern reaches of the Thomsen valley looked more like Scottish highlands than a classical Arctic scene; rolling terrain draped in bright green. Rain falls constantly, a stark contrast to the Arctic desert pictured in textbooks.

surprisingly green
Thomsen River Bank
surprisingly green 2
Grassy hillsides in northern Aulavik Park

As a researcher, I’d come to Aulavik to look at permafrost slumps, and how they chemically impact the aquatic ecosystem. The damage is obvious – jagged scars of black earth run down the sides of mountains, draining into muddy riverbanks below. It’s visible from miles away. What’s less visible is what is actually in the slumps. The clear water of the Thomsen River flows brown for kilometers downstream of the muddy wounds, but without samples to analyze, such descriptions are meaningless. So, we began a canoe trip spanning over 100 km, riding the Thomsen as it rolls into the Arctic Ocean.

Soils provide records of the past, and the sediments of Aulavik, locked in permafrost, tell a history different from the rocky spars of the eastern Arctic. Southern soils are sandy, dull and pale brown, whereas the northern reaches of the park darken to near black. Mounds of vegetation give way underfoot, releasing pools of tea-colored water in each footprint; in moments, those footprints vanish as the ground springs back, seemingly eager to erase any trace of our presence. Strange patterns of narrow gullies and raised hillocks stretch across the valleys, interspersed by shallow, dark lakes. No one has ever cultivated these lands, and nobody is sure what’s in the ground. This is why we need to gather samples from both the soil itself and the water in tandem.

slumps in the distance
Black streaks of visible permafrost slumping in Aulavik Park

Sample gathering for trace metals in water is challenging. Out in the field, in the snow and wind, there can be many complications. We needed two people for the clean hands-dirty hands protocol – one person is ‘clean hands’ and is the only one who comes into direct contact with the sampling environment, the samples themselves, and the containers that hold the samples. The other is ‘dirty hands’, and is responsible for handling more or less everything else. This method is designed to avoid contamination at all costs, and under harsh conditions it’s absolutely necessary to make sure everything is done properly. The biggest complication was never the weather, but the ‘wildlife’: when the temperature got above 6 degrees or so, bugs would start appearing, like some strange haze rising from the soil.

Water sampling in southern Aulavik Park

Thankfully it was usually too cold (we were in Canada’s coldest spot for a while there!) but when they could fly, they would fly into everything: sample bottles, gloves (as you’re putting them on), clothes, hair, ziplock bags, open mouths.

Permafrost cores were also collected. Depending on what’s in the permafrost, there are a huge variety of ways the slumps could impact the waters. Heavy metals such as mercury could find their way into phytoplankton, the base of the food chain. Mercury in particular can be methylated via bacterial processes and then easily sequester itself into basal biota, at which point it poses a risk to more complex forms of life further up the food chain [1]. Mercury was suspect number 1 in the tests we conducted.

Tests are ongoing, but initial analysis reveals a pristine river, with minimal mercury impacts in even the densest slumps. This, at least, is good news for the ecosystem. So far. Only total mercury concentration has been examined to date, and mercury’s toxicity varies drastically depending on speciation. Of key interest are organo-mercury compounds, which are not only very toxic but tend to sequester in tissue and biomagnify up the food chain [2,3]. Depending on the methyl mercury (and to a less extent dimethyl mercury, which usually degrades into methyl mercury in situ), the river’s fish population may have excessive mercury loads.

On the carbon side, chemical changes are obvious; the volume of soil and nutrients draining into the river from the permafrost melt is massive. Organic carbon compounds form the bedrock for all manner of food webs in natural waters, but whether this is good news or not is up for debate. Rapid changes in fragile, easily disturbed ecosystems have a habit of causing problems, even if it would at first appear that a simple equation of more food equals more productive river would apply. As we look into the specifics of the system, we can hopefully answer questions about the river’s health and apply them to similar Arctic ecosystems, many of which are changing rapidly today.

Neal Bailey studies environmental chemistry at University of Manitoba. Previously a writer, he was drawn to environmental science both for its contemporary relevance, and the option to work in both laboratory and natural environments.


  1. Chasar et al; Mercury Cycling in Stream Ecosystems. 3. Trophic Dynamics and Methylmercury Bioaccumulation; Environmental Science and Technology (2009), Vol 43 Issue 8 pp 2733-2739
  2. Morel F. M. M., Kraepiel A. M. L., Amyot M.; The Chemical Cycle and Bioaccumulation of Mercury; Annual Review of Ecology and Systematics (1998), Vol 29 pp 543-566
  3. Mason R. P., Reinfelder J. R., Morel F. M. M.; Bioaccumulation of Mercury and Methylmercury; Water Air and Soil Pollution (1995), Vol 80 Issue 1-4 pp 915-921

Our Role in Combating Pseudoscience

By Mandy McDougall

The prevalence of pseudoscience in our society is getting out of hand.

Pseudoscience (including bad science, chemophobia, and full-fledged anti-science) presents itself as a multidisciplinary problem. Though many pseudoscientific claims concern personal and public health (for instance, vaccines and vaccine-preventable diseases, homoeopathy, and ‘detox’ cleanses), some also concern environmental toxicology, including misconceptions surrounding many environmentally relevant compounds, such as pesticides. Although pseudoscience is by no means a new phenomenon, tea detox advertisements and chemtrail conspiracy theory pages are now polluting the internet and social media. When combined with the growing glorification of pursuing ‘alternative’ agricultural and medical practices, pseudoscience often tries to disguise itself as quality science.

Such frequent disregard of the scientific method calls for scientists – particularly toxicologists – to play a vital role in tackling pseudoscience. Those who understand the science have an obligation to passionately and unapologetically communicate the threats of pseudoscience as it relates to public health, food security, and scientific literacy. How many times have you seen ads for a ‘chemical-free’ dish soap, granola bar, or makeup powder? Seems innocent enough, but excusing bad science in marketing is just the beginning of something much worse.

Overall, this issue is bigger than the specific area of toxicology or chemistry that we study. People are being encouraged to put their families, their children, and public health at risk, on account of advice from sources claiming to be an enlightened alternative to the evil ‘Bigs’ – Big Pharma, Big Ag, Big Chem – you get the picture.

Some people have adopted a reaction whereby they believe that any product developed by a large company – let’s say pesticides – is inherently bad. No questions asked; no case-by-case evaluation; no room for logic and reasoning. These knee-jerk reactions to words like ‘pesticide’ and ‘chemical’ are brought on by fear-mongering campaigns and clever marketing schemes for ‘alternative’ products. There is this unfounded assumption that in maintaining a healthy environment, the use of conventional pesticides cannot occur. However, these two things are not, as some may think, mutually exclusive.

Perhaps the most well-known example of this involves the continued use of DDT (dichlorodiphenyltrichloroethane) in select tropical regions of the world. DDT was once believed to be completely safe for widespread application. However, we eventually learned about the long-term bioaccumulative and toxic effects related to DDT exposure in ecosystems, wildlife, and humans.

Despite these serious toxicological concerns, DDT is still approved for use in certain regions of the world in an effort to combat malaria. Such decisions are the result of complex risk assessments. When the benefits of DDT’s anti-malaria properties are weighed against the adverse long-term bioaccumulative and toxic effects of exposure to the compound, DDT use wins in some cases, but not in others. It is important to remember that the world is full of wicked problems where there fails to be one ‘right’ solution. In such cases, pragmatic problem solving prevails over ideological thinking. In environmental decision-making, a one-size-fits-all solution is often unachievable. We must look at the evidence and calculate the potential benefits and costs via the risk assessment process.

That being said, an important question to ask someone standing firm in their anti-science or pseudoscientific position is, “What would it take to change your mind on this issue?”, whether it be vaccine safety, the impracticality of detox cleanses, or agrochemicals. To someone who is concerned about the potential effects of a herbicide like glyphosate, you may, as an environmental toxicologist, want to challenge their claim that glyphosate is inherently a ‘bad chemical’. You may explain the role of route and exposure in estimating the risk of toxic effects from pesticides and herbicides. You may explain to them what it actually means when something is labelled as a ‘probable carcinogen’. You may explain how the International Agency for Research on Cancer (IARC), like most organizations, has their own agenda.

If nothing you say could ever make them even consider a different perspective, it means that they are no longer thinking in terms of scientific truth, but simply in their beliefs. Their belief that ‘chemicals are bad for the environment’ is no different from other types of beliefs. No amount of scientific data could change their perspective on ‘chemicals’. Ultimately, such beliefs stem from a lack of knowledge in chemistry and toxicology. Although they may consider themselves enlightened because they believe in information contrary to ‘mainstream science’, this does not mean that what they believe is legitimate.

It is likely that some of this mistrust stems from a lack of transparency and effective communication on behalf of regulators and environmental scientists. We will have to first overcome this lingering mistrust between scientists and the public. Twitter feuds and debates just seem to further divide the ‘conventional’ and ‘alternative’ science communities. To promote effective communication, advanced facilitation techniques are probably necessary. The main objective here should be to search for an idea or statement that both an agrochemical scientist and environmental activist could agree on. For instance, perhaps a statement like, “Pesticides have the potential to harm the environment and those who live within it” may be appropriate. I’m sure that there are situations in which both parties would believe this to be true. Once some common ground is established, subsequent conversations will likely be less defensive and circular.

Environmental pollution has been and continues to be, detrimental to the air, water, soil, and well-being of many communities worldwide. From biomagnification of harmful contaminants in Northern communities to hydrocarbon pollution at abandoned gas stations, environmental pollution is prevalent and a constant threat to humans, wildlife, and ecosystems. I began studying environmental toxicology because of my love for nature and the desire to protect the environment against anthropogenic harm – from a rational, scientific approach. Without this, we cannot know where to prioritize our efforts and would be easily distracted by the claims of pseudoscience enthusiasts.

I end with a plea. My plea to students studying environmental chemistry and toxicology is to speak up for sound science. Being a scientist does not disqualify us from sharing knowledge outside of an academic journal or a conference poster. If anything, we should feel compelled and eager, if not obliged, to contribute to such conversations.

Don’t let companies get away with marketing ‘chemical-free’ products. Don’t let your friends spread misinformation from websites with questionable agendas. It might seem innocent enough, but it’s these same ideas that influenced parents, in several instances, to attempt to cure their children’s very treatable diseases using pseudoscientific approaches, sadly resulting in their death. At some point, an innocent lack of scientific literacy grows to become a danger to public health, food systems, and the overall integrity of science. So for me, this is no longer just about silly semantics. It’s about our role in shaping a society equipped to interpret and challenge information.



Mandy is a graduate student at Simon Fraser University studying bioaccumulation behaviour of perfluorinated compounds in marine food webs.

Our World at the Nanoscale

By Alexis Wormington

What are nanoparticles?

Nanoparticles are particles with at least one dimension sized on the nanoscale, which is usually defined as 1-100 nanometers1 (Figure 1). Put in simpler terms, nanoparticles are very small.


Figure 1. The nanoscale2

Nanoparticles are on the same scale as many biomolecules, including antibodies, proteins, and sugars. We can’t see them, but, just like bacteria, they’re all over the place!

Where do nanoparticles come from?

Nanoparticles occur naturally in the environment – common sources include volcanic ash, ocean spray, dust, and sand3. Researchers are primarily interested in nanoparticles of synthetic (man-made) origin. Synthetic nanoparticles can be unintentional by-products of many commercial processes or intentionally synthesized for a variety of technological and industrial applications4. The latter are commonly referred to as engineered nanoparticles or engineered nanomaterials.

How do we use nanoparticles?

There are hundreds of different types of nanoparticles, and researchers are constantly engineering new ones in order to expand and invigorate the field of nanotechnology. Nanoparticles can be produced from a variety of elements, including carbon and metals such as titanium, gold, and silver.

Nanoparticles are interesting and useful because they have unique thermal, chemical, and optical properties compared to their larger, bulk elemental counterparts. These properties lend to a variety of applications, including those in the medical, environmental, engineering, technology, and commercial industries. Nanoparticles are often used as conductors in circuits and displays in electronic devices5, in textiles to improve or add functionalities (such as bacterial resistance, breathability, and strength6), as targeted drug-delivery vehicles in many cancer therapies7, and in environmental remediation efforts to bind and neutralize toxins.8


Figure 2. The many applications of nanotechnology9.

In other words, nanoparticles are everywhere! For example, the active ingredient in most SPF (sun protection factor) cosmetics is zinc or titanium dioxide nanoparticles. Soon, carbon nanotubes will replace silicon as semi-conducting transistors inside of our computers and smartphones. Some make-up products even contain gold nanoparticles!

Nanoparticles sound awesome – should we be concerned about them?

In the last ten years, the presence of nano-enabled (contains nanoparticles or nanoscale materials) products on the consumer market has increased exponentially. The Project on Emerging Nanotechnologies works on documenting nano-enabled consumer products in something called a Consumer Products Inventory (CPI). As of 2014, the CPI lists 1814 nano-enabled products currently available on the consumer market, compared to just 54 products listed in 200510. That’s an average increase of 362% every year!

A consumer market full of nano-enabled products means that nanoparticles and nanomaterials will inevitably end up in the surrounding environment – which means the water we drink and the air we breathe. The Environmental Protection Agency is currently researching the “most prevalent nanomaterials that may have human and environmental health implications”, which includes silver nanoparticles, carbon nanotubes, cerium and titanium dioxide, iron nanoparticles, and copper nanoparticles11.

The health implications of exposure to nanoparticles vary depending on the type of particle and the route of exposure, but researchers have proposed that nanoparticles smaller than 10 nm can enter biological tissue12. Silver nanoparticles, utilized commonly in the textile industry for their antibacterial properties, release silver ions which are associated with mitochondrial and oxidative damage in both vertebrates and invertebrates13. A famous pilot study published in Nature Nanotechnology in 2008 found that commercially available carbon nanotube fibers induced mesothelioma-like pathologies in the abdominal cavity of mice due to their structural similarity to asbestos14. Copper oxide nanoparticles, used not only as a semi-conductor but as the active spermicide in many intrauterine devices (a form of long-term birth control), are associated with multiple organ-level effects in experimental organisms15.

There are many organizations around the world that specialize in nanosafety research. These research groups focus on understanding the behavior of nanoparticles throughout the life cycle (manufacturing, product use, and disposal) in order to determine whether they pose a potential threat to humans or the environment11. This can be a daunting task – because some types of nanomaterials are more harmful than others, and some exposure scenarios are more relevant than others (i.e. inhalation versus ingestion versus injection). Nanoparticles are also maddeningly difficult to detect, which makes studying them a headache! For example, detecting carbon nanotubes in biological tissues is often described as “searching for a carbon needle in a carbon haystack”, and detection methods are still being optimized. Detection methods vary for different types of nanoparticles and range from microscopic methods (such as transmission electron microscopy), to light scattering methods, to spectroscopy techniques, to x-ray based methods16. Often times, researchers will send their samples off to another lab for quantification, because they simply do not have the proper equipment at hand!

Nanoparticles, while useful and incredibly versatile, should be approached with caution. The research on them is still in the preliminary stages, and there is still much we do not know about their potential effects on human and environmental health. As the field of nanotechnology grows, it is important to remain informed and vigilant to ensure that these particles are used safely and efficiently.


Alexis Wormington
is a PhD Student at the Center for Environmental Toxicology & Chemistry at the University of Florida. Her research is focused on the toxicity of nanomaterials in aquatic ecosystems.



  1. “Nanomaterials.” National Institutes of Environmental Health Sciences. National Institute of Health, n.d. Web. 11 Jan. 2017.
  2. Tarafdar, J.C., Adhikari, T. (2015). Nanotechnology in Soil Science. In Ratten, R.K. et al (Eds.), Soil Science: An Introduction (pp 775-807).
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  11. “Research on Nanomaterials.” EPA. Environmental Protection Agency, 18 Oct. 2016. Web. 11 Jan. 2017.
  12. Bahadar, H., Maqbool, F., Niaz, K., & Abdollahi, M. (2015). Toxicity of Nanoparticles and an Overview of Current Experimental Models. Iranian biomedical journal, 20(1), 1-11.
  13. Stensberg, M. C., Wei, Q., McLamore, E. S., Porterfield, D. M., Wei, A., & Sepúlveda, M. S. (2011). Toxicological studies on silver nanoparticles: challenges and opportunities in assessment, monitoring and imaging. Nanomedicine, 6(5), 879-898.
  14. Poland, C. A., Duffin, R., Kinloch, I., Maynard, A., Wallace, W. A., Seaton, A., … & Donaldson, K. (2008). Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study. Nature nanotechnology, 3(7), 423-428.
  15. Bahadar, H., Maqbool, F., Niaz, K., & Abdollahi, M. (2015). Toxicity of Nanoparticles and an Overview of Current Experimental Models. Iranian biomedical journal, 20(1), 1-11.
  16. López-Serrano, A., Olivas, R. M., Landaluze, J. S., & Cámara, C. (2014). Nanoparticles: a global vision. Characterization, separation, and quantification methods. Potential environmental and health impact. Analytical Methods, 6(1), 38-56.

How I ended up in the Arctic

By Sara Pedro

I became interested in contamination of the polar regions during my master’s while researching mercury concentrations in Antarctic Gentoo penguins (Pygoscelis papua). This species spends their complete life cycle in many of the sub-Antarctic islands, such as South Georgia and the Kerguelen Islands, and reproduce in colonies of about 320 000 breeding pairs (Borboroglu and Boersma 2013). Because of their large numbers, wide distribution in the Antarctic Ocean, and easy access, Gentoo penguins are good biomonitors of local contaminant concentrations; a major reason we studied this species. We found that mercury concentrations in Gentoo penguins were not at concerning levels (Pedro et al. 2015). Nevertheless, the fact that mercury accumulates in species in the Antarctic, one of the most remote regions in the world, indicates the widespread contamination of pollutants released mostly in industrialized areas.

In transitioning to my PhD, I switched poles to focus on the Arctic. Like in the Antarctic, the Arctic region is impacted by global pollution. At the same time, the Arctic has been facing marked sea-ice loss associated with increasing temperatures. The Arctic is more susceptible to these changes in climate than other regions around the globe (Screen and Simmonds 2010) due to the albedo effect: less sea-ice to reflect solar radiation leads to more absorption by the ‘darker’ ocean surface. Because contaminants are transported by air and oceanic currents, climate change will likely alter contaminant dynamics and pathways into Arctic ecosystems (Macdonald et al. 2005). One situation that leads to this change in contaminant dynamics is the alteration of Arctic food web structure, such as the replacement of native with invasive prey fish.

My current PhD project at the University of Connecticut focuses on legacy persistent organic pollutants (POPs) and mercury in invasive versus native prey fish in the Eastern Canadian Arctic, and consequent levels in ringed seals (Pusa hispida). Legacy POPs include several pesticides and polychlorinated biphenyls (PCBs) that can travel long distances, often by atmospheric transport, eventually accumulating in remote regions. These POPs take a long time to break down in the environment, and can accumulate in animals to potentially cause toxic effects (Letcher et al. 2010). Mercury is released mainly during gold mining and coal burning and is transported to remote regions where, similarly to POPs, it can accumulate in the food web and cause toxic effects (Dietz et al. 2013).

With the recent increases in average temperatures in the Arctic, some fish species have expanded their habitat ranges from boreal areas to more northern regions and are now found more frequently in the Canadian Arctic. Studies on Arctic seabird and marine mammal diets suggest that invasive fish such as capelin (Mallotus villosus) and sand lance (Ammodytes sp.) are replacing Arctic cod (Boreogadus saida) as the most important prey species in lower Arctic regions (Provencher et al. 2012; Chambellant et al. 2013; Hop and Gjøsæter 2013). Although POPs and mercury are transported to the Arctic, they are still at higher environmental levels closer to the direct sources (e.g. intense agricultural areas, waste incineration). A switch in diet from native to invasive fishes may therefore change ringed seal contaminant burdens. My PhD research will compare contaminant levels in invasive capelin and sand lance to Arctic native fish species, including Arctic cod. I will also determine contaminant levels in ringed seals to better understand how climate change impacts contaminant transfer in Arctic food webs. The results of this project are also important for local communities because, although they do not eat these invasive and native Arctic fishes in particular, locals eat Arctic marine mammals, such as ringed seals that feed on these fishes.

Part of this project includes visiting the local communities in the Arctic that are the most affected by these habitat changes. Arviat, Nunavut is one of the communities collaborating in this project and participated in collecting fish samples. This was my opportunity to visit the Arctic! Last spring, I flew up to Arviat (Figure 1) and gave a few talks regarding preliminary results of my research at the high school, the Arctic College, and the Hunters and Trappers Association.

Figure 1: Town of Arviat, Nunavut (left) in the Eastern Canadian Arctic (right).

My visit in April was short and sweet, consisting of 4 different flights each way… 8 flights in three days (luckily, none of the flights were delayed)! Given the thaw doesn’t happen until June/July in Arviat, late April means snow boots and warm coats. Hudson Bay was a beautiful, expansive white plain (Figure 2)! However, I could tell that it was the spring for them. The locals were walking on the streets, kids were out playing and the roads were clear enough to easily drive through. Everyone looked happy and they were very welcoming. At the high school, I gave a few talks to different classes about my research. The students were interested and engaged, and I even got the wise question “So why does this matter?” from a 12-year-old. Another girl told me that she didn’t like fish and when I asked what she eats instead, she told me about how her father hunts caribou. She invited me to join them on a hunt. If it weren’t for my tight schedule, I would have definitely gone out for a caribou hunt! In this region, they mostly depend on caribou (Rangifer tarandus), seals, and Arctic char (Salvelinus alpinus) for subsistence. High school students will often miss classes and come in tired because the main priority for many of them is to help their families hunt and fish.

Figure 2: Frozen Hudson Bay in Arviat, NU

After visiting the high school, I went to the Arctic College (Figure 3). Most of the students were gone for the summer but I met a few that stick around and volunteer for research projects. Getting locals involved in environmental research in these remote regions is very important given their sensitivity to climate change and environmental pollution. Fishers and hunters at the Hunters and Trappers Association are concerned about having contaminants in their food, since they depend largely on local food sources. The Arctic Monitoring and Assessment Program (AMAP) has been monitoring contaminants in the Canadian Arctic for over twenty years. The levels of some POPs, such as DDT and PCBs have been declining or have stabilized in the Arctic, mostly since the Stockholm Convention to ban these contaminants (Stockholm Convention 2008). However other contaminants such as mercury have been increasing in some Arctic animals (Riget et al. 2010; McKinney et al. 2015). As a polar environmental scientist, it is my duty to continue researching the impacts of climate change on contaminant levels in these remote regions and to address the communities’ questions and concerns.

Figure 3: Arctic College, Arviat, NU

Being able to visit one of the most fascinating regions in the world while doing environmental research is why I enjoy being a scientist!

Sara Pedro has a Master’s in Ecology and is currently a PhD student in the Natural Resources and the Environment department of the University of Connecticut, CT.


Borboroglu PG, Boersma PD (2013) Penguins: Natural History and Conservation. University of Washington Press, Seattle

Chambellant M, Stirling I, Ferguson SH (2013) Temporal variation in western Hudson Bay ringed seal (Phoca hispida) diet in relation to environment. Mar Ecol Prog Ser 481:269.

Dietz R, Sonne C, Basu N, et al (2013) What are the toxicological effects of mercury in Arctic biota? Sci Total Environ 443:775–790. doi: 10.1016/j.scitotenv.2012.11.046

Hop H, Gjøsæter H (2013) Polar cod (Boreogadus saida) and capelin (Mallotus villosus) as key species in marine food webs of the Arctic and the Barents Sea. Mar Biol Res 9:878–894.

Letcher RJ, Bustnes JO, Dietz R, et al (2010) Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish. Sci Total Environ 408:2995–3043. doi: 10.1016/j.scitotenv.2009.10.038

Macdonald RW, Harner T, Fyfe J (2005) Recent climate change in the Arctic and its impact on contaminant pathways and interpretation of temporal trend data. Sci Total Environ 342:5–86. doi: 10.1016/j.scitotenv.2004.12.059

McKinney MA, Pedro S, Dietz R, et al (2015) A review of ecological impacts of global climate change on persistent organic pollutant and mercury pathways and exposures in arctic marine ecosystems. Curr Zool 61:617–628.

Pedro S, Xavier JC, Tavares S, et al (2015) Mercury accumulation in gentoo penguins Pygoscelis papua: spatial, temporal and sexual intraspecific variations. Polar Biol. doi: 10.1007/s00300-015-1697-9

Provencher JF, Gaston  AJ, O’Hara PD, Gilchrist HG (2012) Seabird diet indicates changing Arctic marine communities in eastern Canada. Mar Ecol Prog Ser 454:171–182. doi: 10.3354/meps09299

Riget F, Bignert A, Braune B, et al (2010) Temporal trends of legacy POPs in Arctic biota, an update. Sci Total Environ 408:2874–2884. doi: 10.1016/j.scitotenv.2009.07.036

Screen JA, Simmonds I (2010) The central role of diminishing sea ice in recent Arctic temperature amplification. Nature 464:1334–1337. doi: 10.1038/nature09051

Stockholm Convention (2008) Listing of POPs in the Stockholm Convention. Accessed 28 May 2015

Human Exposure to Pharmaceuticals via Vegetables: Current Research and Future Directions

By Sara Nason

Like many scientists, I often find myself explaining my research to my friends and family.  However, I am usually hesitant to launch into a full explanation of my projects, as most people are not as interested in the mechanisms of how plants take up pharmaceuticals as I am. As soon as I start describing my research, all sorts of questions come up – most of which are not directly related to my work.

When deciding on a topic to write about for the SETAC student blog, I considered focusing on the research that I work on every day.  However, I would probably digress into a detailed description using lots of scientific jargon, and my blog entry would not be very exciting.  Instead, this post is about an issue that often comes up when I discuss my research with someone outside of my field – human exposure to pharmaceuticals that have been taken up by crop plants.  Specifically, I focus here on a recent paper in Environmental Science and Technology by Ora Paltiel and others: Human exposure to wastewater-derived pharmaceuticals in fresh produce: A randomized controlled trial focusing on carbamazepine.1

Scientists working at the Hebrew University of Jerusalem recently detected carbamazepine, an anti-epileptic drug, in the urine of people eating vegetables that were irrigated with treated wastewater.  This is the first study to demonstrate that pharmaceutical contamination in irrigation water results in human exposure to pharmaceuticals via consumption of irrigated crops.

Researchers provided study participants with a box of vegetables to consume over the course of a week. Some participants received vegetables grown with freshwater irrigation, while others received vegetables grown using treated wastewater irrigation. New boxes were provided the following week that only contained vegetables irrigated with freshwater.  The scientists collected urine samples from the participants throughout the two weeks, and found that urine concentrations of carbamazepine increased during the first week for participants eating the treated wastewater vegetables, but not for the freshwater group.  Carbamazepine levels returned to baseline levels by the end of the second week.

Irrigation using treated wastewater is a surprisingly common practice worldwide, especially in arid locations.  In California, where most of the produce in the United States is grown, nearly half of treated wastewater is used for agriculture, and in Israel, more than 70% of treated wastewater is used directly for irrigating crops.2 Pharmaceuticals enter the wastewater treatment system because humans and animals do not fully break down most drugs and a significant portion is excreted in urine. Even in fully industrialized nations, most wastewater treatment does not fully remove pharmaceuticals, so the chemicals go wherever the treated wastewater goes – into lakes, rivers, and streams, or directly onto crop plants.

Plant uptake of pharmaceuticals became a topic of concern starting about 10 years ago, after several studies found pharmaceuticals in run-off water from crop fields.  The first few years of research focused largely on proof-of-concept experiments – tests where plants were grown in labs and greenhouses and exposed to higher concentrations of pharmaceuticals than are typically found in the environment.  These studies showed that plants can take up many types of pharmaceuticals.  More recent studies have investigated exposures to lower concentrations of pharmaceuticals using plants grown in more realistic scenarios, showing that the potential for plants to take up pharmaceuticals in standard agricultural systems clearly exists.3

The big question that is still up for debate is whether or not human exposure to pharmaceuticals via consumption of contaminated crops might have impacts on human health. Within the big question, there are two smaller questions that are the focus of current research.

Figure 1: A recent publication demonstrates that people can be exposed to pharmaceuticals by eating vegetables that were irrigated with treated wastewater. Continuing research focuses on understanding the exposure pathway well enough to predict any potential health impacts.

First, we need to know more about the effects low concentrations of pharmaceuticals may have on human health – at what amount (in plants) will pharmaceuticals begin to have an effect on people?  Pharmaceuticals in the environment are usually present as mixtures, so although the concentration of each one may not be close to a normal therapeutic dose, there could be unexpected effects from drug mixtures and interactions.  While scientists are currently researching the effects of very low doses of pharmaceutical mixtures, much of the research that has been done so far has focused on model organisms for aquatic ecosystems, such as water fleas, zebra fish, and minnows, rather than on plants and humans. Most human risk assessment so far has used estimates of toxicity based on the molecular structure of pharmaceuticals and not on experimental data.

Second, we need to have a better understanding of how much of different pharmaceuticals is being taken up by crop plants in the field – enough to meet the threshold for effects on humans? While more than 100 pharmaceuticals have been studied in plant uptake experiments,3 thousands more are currently in use, with new drugs constantly being developed.  Testing all produce samples for the presence of pharmaceuticals is highly impractical, so accurate predictions of plant uptake are necessary. Some scientists have attempted to use models to predict plant uptake, but there are still large gaps in our understanding of the biological and chemical processes involved.

My research focuses on these knowledge gaps – I look at variables such as soil pH, nutrient availability, and toxicity of pharmaceuticals to plants – factors that may affect how much of a pharmaceutical can enter and accumulate in a plant. I work with model organisms and do a lot of method development – things that don’t feel relevant to the outside world by themselves. Reading articles like the one described above and thinking about the larger questions connected to my research makes me feel like a part of the greater scientific community and like I am doing something of significance for the world.  I think that is one of the great things about being in the environmental toxicology and chemistry field.  It will be exciting to see where the science goes next!

Sara Nason is a PhD student in Environmental Chemistry and Technology at the University of Wisconsin-Madison


(1)        Paltiel, O.; Fedorova, G.; Tadmor, G.; Kleinstern, G.; Maor, Y.; Chefetz, B. Human exposure to wastewater-derived pharmaceuticals in fresh produce: A randomized controlled trial focusing on carbamazepine. Environ. Sci. Technol. 2016, acs.est.5b06256.

(2)        Sato, T.; Qadir, M.; Yamamoto, S.; Endo, T.; Zahoor, A. Global, regional, and country level need for data on wastewater generation, treatment, and use. Agric. Water Manag. 2013, 130, 1–13.

(3)        Miller, E. L.; Nason, S. L.; Karthikeyan, K.; Pedersen, J. A. Root Uptake of Pharmaceutical and Personal Care Product Ingredients. Environ. Sci. Technol. 2015, acs.est.5b01546.

Formulating Future Career Options within Green Chemistry

By Alicia McCarthy

Green chemistry, according to the Environmental Protection Agency (EPA), is the design of chemical products and processes that take into consideration the entire life cycle to reduce and eliminate the use or generation of hazardous chemicals. An aspect of green chemistry that can, at times, be overlooked is the communication up and down the supply chain of a substance. It is easy to sum up good practices for green chemistry, but it is another thing to implement those principles.

During my academic career, I knew I was passionate about sustainable chemistry, toxicology, and environmental health, but I had no idea what career options I had beyond what was listed in my major’s brochure. I took the time to reach out to professionals I met through my university and at conferences to hear about their own journey. When I was curious about certain career directions, I actively looked to join projects that would help me get a taste for different fields relating to green chemistry and toxicology. These projects provided hands-on experience and facilitated interaction with professionals, allowing me to see the bigger picture of substances from upstream, which could be the development and manufacturing of a substance, and following it downstream where it reaches end-users; revealing where the practice of green chemistry principles are or should be implemented.

When green chemistry principles are not initially utilized, certain occupations and fields become vital to the protection of human health and the environment. This blog will discuss a few areas related to green chemistry that I have learned about from my own experiences. There are plenty of other areas that benefit from a background in green chemistry and toxicology, but in this post I will go over hazard communication, recycling, chemical policy, environmental certification organizations and third party testing laboratories, formulation, the military and medical writers.

Hazard Communication

Communication is essential during the entire lifecycle of a substance; from the formulator to the recycling or disposal workers. Most workers that use hazardous substances only have labels to depend on to warn them of risks. However, there is a considerable difference between hazard and risk that is posed by a substance. The hazard will be present in all situations due to a substance’s intrinsic chemical or physical properties, but a risk posed by a substance is dependent on how a substance is handled, contained, and transported.

Whether on a global, national, state, or industry level, hazard communication is a field that has many opportunities for refinement. Countries adopt different editions of the GHS (Globally Harmonized System), and there are still inconsistent substance classifications on national harmonized lists. Just because there is a harmonized system does not mean there is harmonized labeling. Labeling and classification is dependent on hazard groups, categories adopted, editions of GHS utilized, national substance classification lists, country-specific requirements, and many other factors. Understanding the variables associated with national adoption of GHS brings opportunities to improve hazard communication.

Substances may be intended for one type of function, or for use in a mixture, however when downstream users are untrained in the risks of straying from those expected functions, the specific hazards and precautionary measures defined by the manufacturer may no longer be relevant. Having knowledge of chemical reactions and properties, mechanistic toxicology, and green chemistry can assist when training and educating workers and suppliers about the risks that go beyond the scope of the SDS (Safety Data Sheet) or GHS labeling.

With new technologies will come new human health and environmental toxicity risks; 3D printers and carbon nanotubes are just a few examples of emerging technologies that lack complete hazard communication and full risk assessments. Hazard communication can be the gatekeeper when it comes to risk assessments of substances like these, especially when certain risk assessment tools rely heavily on SDS. Missing toxicological information on a substance, trade secrets, or availability of in-house alternatives for substances are dependent on hazard communication professionals who contribute to these important policies and documents. For more information on careers in this field, the Society of Chemical Hazard Communication is a great way to talk to professionals and learn about opportunities in this area.

Recycling Specialist

The reuse and recycling of substances and waste produced by industrial processes or consumer articles are also within the scope of green chemistry. Those with degrees in chemistry, environmental health, and toxicology are crucial to the understanding of a substances fate, exposure, and potential effects at the end of the pipeline, especially if an article or substance is being transformed into something else. Many businesses, as well as cities and states hire recycling specialists to help develop and run recycling programs.

When recycled, some materials can expose workers to toxic chemicals that would not have been released in the original state. The reuse of substances can also pose a potential health risk depending on the original material. An example of this would be tires used to make turf fields. Businesses that reuse material need to have the expertise of chemists who understand environmental health and consider the life cycle of the new product and any new exposures the frontline workers may face. This is an area that is often forgotten within green chemistry, but it is a growing process for companies looking to save money and reduce costs of disposal.

Chemical Policy: Agencies, Institutions, and Organizations (United States and Europe)

Many of the exposure limits set by national agencies are allowable concentrations defined between industry, third party laboratories, government agencies, and other organizations. Chemical policy is always changing around the world and having expertise in green chemistry and toxicology can help contribute to a better “big picture” view. Knowledge of mechanistic toxicology and chemistry is important for knowing how to test certain substances and not expect that all will react in the same way, e.g., endocrine disrupting chemicals and the ongoing debate on the criteria to test and regulate.

In the United States, the National Institute for Occupational Safety and Health (NIOSH) is a federal agency that is part of the U.S Centers for Disease Control and Prevention (CDC). NIOSH helps promote safe and healthy workers through interventions, recommendations, and capacity building. NIOSH has a diverse range of employees in the fields of epidemiology, medicine, nursing, industrial hygiene, chemistry, and different branches of engineering. OSHA works closely with NIOSH to create standards for occupational health. The EPA is another agency that plays a huge role in chemical policy and the research of substances. The EPA promotes the usage of green chemistry principles within their own laboratories, certification programs, and through grants.

On state and local levels within the United States, there are institutes and organizations that assist in the research, education, and professional opinion within chemical policy. Some examples of these would be Silent Spring Institute, The Endocrine Disruption Exchange, The Campaign for Safer Cosmetics, Warner Babcock Institute, the Office of Environmental Health Hazard Assessment (OEHHA), and the Toxic Use Reduction Institute (TURI). I recommend students and early professionals to learn what organizations or institutes are out there that share your interests, and talk with people who work at these places to find out what steps they took to advance their careers.

In Europe, the European Chemical Agency (ECHA) is in charge of the European Union (EU) regulation called REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals). There are also sectors of the European Commission that impact chemical policy such as the Directorate-General for Environment and the Directorate-General for Industry and Enterprises. Every country within the EU also has their own agencies, institutions, organizations, and trade unions that have their own research and development of safer substances.

Creating ties through volunteer work, internships, or pathway programs is a great way to secure a longer-term position at an institution or agency involved in policy. Internships abroad are also a great way to learn about other chemical policy systems. Do not restrict yourself to just the United States or the EU; look globally to see what is going on in chemical policy and what career options are available in other countries.

Environmental Certification Organizations / Third Party Testing Laboratories

Non-profit environmental certification organizations, like Green Seal, are another area offering jobs involving green chemistry. Green Seal provides science-based environmental certification standards to help manufacturers, purchasers, and consumers from cradle to grave and improve product quality. Not only do they certify products, but they also provide education and guidance for a more sustainable world. Safer Choice, by the EPA, is another certification that researches chemical toxicology and works with industry to improve health safety.

Research for certification of these labels also comes from third party testing laboratories, such as  TURI. Work at third party laboratories allows for experience in quality control, reformulation, and evaluation of comparative products already on the market. It is also a great way to get familiar with industry, regulations, and quality documentation.

Green Chemistry Formulation

Formulators are the first line of prevention of hazardous substances. Although most formulators work within the restriction of a company’s methods, some institutions and businesses look for those with an understanding and background in green chemistry for not only ethical reasons but also to reduce occupational disease costs.

An example of a type of business looking for chemists with a green chemistry background is a correctional facility. MassCor provides inmates training and skills through work that provides quality products at a competitive price. They recently hired a student who worked at TURI Laboratories as a head formulator for one of the Massachusetts correctional institutions to instruct the inmates within the shop department to manufacture Green Seal certified janitorial products. This position eventually will allow the formulator to innovate new formulations for these products that are safe for the inmates to create within a correctional institutional environment.

Commission Corps / Military Specialist

There is a section of the United States military that people in the public health, toxicology, and chemistry field may qualify for: the Commission Corps. Those who join can work as science and research health professional officers. These officers conduct cutting-edge research on public health topics for scientific and medical discoveries within the United States or abroad, and they provide oversight for national health research and development. Some of the distinct disciplines within this branch of the military include epidemiology, chemistry, toxicology, and microbiology.

Medical Writer

Toxicology and green chemistry research may eventually be distributed to the public. Readability of this information takes knowledge and skill so that the topic is accessible without being diluted or oversimplified. Nonprofits, hospitals, and even industry need people who have the writing skills and education to relay this information in layperson’s terms. The average readability level within the health field is 7th to 8th grade among Americans. In some cases, it can go as low as a 3rd grade reading level. Explaining important health risks and research at these levels is a huge asset and facilitates engagement at the community (tax-payer’s) level.

These are just a few of the career areas that intertwine toxicology and green chemistry. Most of the opportunities and jobs that I have been able to experience are due to putting myself out there and just asking to be a part of something. Even more so, the skills I have gained are partially due to finding mentors that are willing to help me grow within the many factions of green chemistry and environmental health. Connect with your professors and colleagues and get involved with associations. Find the people who inspire you and ask them to share stories of their own professional journeys. Stories from people in your field can give you amazing tips, areas to strengthen, information on current projects, more connections, and allow you to reflect on your own professional path. Never be afraid to actively ask to be a part of a project or apply for positions that may be a little bit outside of your experience.

AliciMcCarthya McCarthy graduated with a BS in Environmental Health and is currently in the Occupational and Environmental Hygiene Master’s program at the University of Massachusetts Lowell. She is a Research Assistant and CHO at the Toxic Use Reduction Institute Laboratory. Alicia is an intern at the ETUI this summer in Brussels, Belgium.

AliciaMcCarthy88 (at)

Antimicrobial Soaps and Other Products of Questionable Necessity

By David Faulkner

We’ve all seen phrases like “anti-bacterial” and “anti-microbial” emblazoned across aisles of imperious bottles of various soaps, and increasingly in other products such as cutting boards, gym bags and socks. But what is the purpose of antimicrobial compounds in these products? And do we truly need antimicrobial compounds to clean ourselves? The answers are nuanced, and depend on the product in question, but to begin with, we will consider a narrower case, for which there is ample evidence: hand soaps. To discuss the necessity of antimicrobials in hand soaps, let us begin by considering the process of hand washing to begin with.

We wash our hands to reduce disease transmission, and study after study has shown that proper hand washing before preparing and eating food can dramatically reduce rates of diarrheal diseases. Additional studies (1,2) have indicated that stringent hand washing regimens are vital in combating disease outbreaks in hospitals. Unfortunately, most of us don’t wash our hands for the recommended twenty seconds of scrubbing. In fact, one study found that health care workers washed their hands for just under nine seconds on average, while non-healthcare workers spent a little over four seconds at the faucet. The problem with this, is that while it may be satisfying to work up a good lather and rinse it off, the friction of rubbing your hands together and the flow of water to carry the bacteria away are the key to removing unwanted dirt and microbes. And the soap, while helpful for dislodging stubborn dirt and biofilms, is probably not as important as the running water when it comes to removing harmful bacteria – assuming that you’re washing properly. Why, then, is antibacterial soap so popular?

Part of the reason why antibacterial soaps are popular is because they’re useful: multiple studies have shown that they can be used effectively to control outbreaks of hospital-born illnesses, and the FDA has determined that the popular antimicrobial agent Triclosan is useful for controlling cavities and gum disease when added to toothpaste. Most people know that bacteria can make us sick, so it’s natural to think that if regular soap is good, then antibacterial soap must be better. Unfortunately, there’s not much evidence that this is the case for most products, in part because the concentration of antimicrobials found in consumer hand soaps is much lower than the concentrations used in hospital hand soaps, and in part because most people don’t wash their hands for long enough for it to matter anyway. But good marketing is good marketing, and consequently, antibacterial agents like Triclosan has been added to soaps and a menagerie of other products on the premise that it will kill the bacteria that cause disease and unpleasant odors – although the latter claim is even more questionable.

Triclosan is an antimicrobial agent, meaning that it kills microorganisms like bacteria and fungi. It’s considered a broad-spectrum antimicrobial because it can kill a wide variety of microbes, rather than only a specific type. This is because one of the ways that it kills microbial cells is by disrupting the membranes that make up the exterior and inner compartments of the cells, causing their contents to leak. There are several other ways that Triclosan kills bacteria, and one of them is similar to the way that other antibiotics kill bacteria – meaning that if bacteria develop resistance to Triclosan, they may become resistant to other antibiotics as well.  Resistance develops when a few bacteria survive an exposure to Triclosan, and they do so because they have developed mutations in their genes that protect them from the chemical. These bacteria then proliferate and can pass the Triclosan-resistance genes on to other bacteria, making them immune as well! Antibiotic resistance affects over 2 million people in the United States each year – some lethally so – and those numbers are increasing. One study found that by the year 2050, antibiotic resistance may cost the world economy over $100 trillion USD (4).

Unfortunately, the risk of antibiotic resistance is not the only reason why we need to reconsider the use of Triclosan in consumer products: growing evidence suggests that it may pose a hazard to human and environmental health as well (5, 6, 7). Much of the Triclosan that enters the environment does so via our sinks and drains when we wash our hands or brush our teeth with products that contain the compound. Not all water treatment processes destroy Triclosan, and the compound may be released into the environment with the rest of the treated effluent, whereupon exposure to direct sunlight can cause Triclosan to break down into molecules from a potent class of environmental contaminants: dioxins. Algae and other aquatic microorganisms can absorb the Triclosan that doesn’t break down in the sunlight, causing the compound to accumulate in the fish and other animals that eat them. High doses of Triclosan have been shown to affect the swimming ability of fish and to disrupt the function of their muscles, and a number of studies have indicated that Triclosan may cause endocrine disruption in mammals although the specific mechanism by which it does so is poorly understood (6, 7, 8, 9, 10).

All of this is to say that while antibacterial compounds such as Triclosan do have their uses – and are indeed quite effective when used judiciously – they probably aren’t necessary in hand soaps, and may do more harm than good when overused. So while it may be tempting to battle germs with antibacterial soaps, the best thing to do is to simply take your time at the sink. Maybe sing the “Happy Birthday” song once or twice?



David Faulkner is a PhD Candidate in Molecular Toxicology at The University of California at Berkeley. He has a few degrees from the University of Michigan, including a Master’s of Public Health. David’s research interests include green chemistry and hazard assessment of industrial toxicants. In his free time, he enjoys running, writing, and YouTube Videos.

Sources Cited:

  1. Jones, Rhonda D., Hanuman B. Jampani, Jerry L. Newman, and Andrew S. Lee. “Triclosan: a review of effectiveness and safety in health care settings.”American journal of infection control28, no. 2 (2000): 184-196.
  2. Pittet, Didier. “Compliance with hand disinfection and its impact on hospital-acquired infections.” Journal of Hospital Infection 48 (2001): S40-S46.
  3. Arias, Cesar A., and Barbara E. Murray. “A new antibiotic and the evolution of resistance.” New England Journal of Medicine 372, no. 12 (2015): 1168-1170.
  4. Review on Antimicrobial Resistance (London)., and Grande-Bretagne. Antimicrobial resistance: tackling a crisis for the health and wealth of nations. Review on Antimicrobial Resistance, 2014.
  5. Fang, Jia-Long, Robin L. Stingley, Frederick A. Beland, Wafa Harrouk, Debbie L. Lumpkins, and Paul Howard. “Occurrence, efficacy, metabolism, and toxicity of triclosan.” Journal of Environmental Science and Health, Part C 28, no. 3 (2010): 147-171.
  6. Yueh, Mei-Fei, and Robert H. Tukey. “Triclosan: a widespread environmental toxicant with many biological effects.” Annual review of pharmacology and toxicology 56 (2016): 251-272.
  7. Chalew, Talia EA, and Rolf U. Halden. “Environmental exposure of aquatic and terrestrial biota to triclosan and triclocarban1.” JAWRA Journal of the American Water Resources Association 45, no. 1 (2009): 4-13.
  8. Cherednichenko, Gennady, Rui Zhang, Roger A. Bannister, Valeriy Timofeyev, Ning Li, Erika B. Fritsch, Wei Feng et al. “Triclosan impairs excitation–contraction coupling and Ca2+ dynamics in striated muscle.” Proceedings of the National Academy of Sciences 109, no. 35 (2012): 14158-14163.
  9. Fritsch, Erika B., Richard E. Connon, Inge Werner, Rebecca E. Davies, Sebastian Beggel, Wei Feng, and Isaac N. Pessah. “Triclosan impairs swimming behavior and alters expression of excitation-contraction coupling proteins in fathead minnow (Pimephales promelas).” Environmental science & technology 47, no. 4 (2013): 2008-2017.
  10. Stoker, Tammy E., Emily K. Gibson, and Leah M. Zorrilla. “Triclosan exposure modulates estrogen-dependent responses in the female wistar rat.” Toxicological Sciences (2010): kfq180.

Students of SETAC

Alexander MacLeodMacLeod


Graduate Student, University of Maryland, College Park
Research interest: Endocrine disruption, immune function, ecotoxicology, fish biology

Leah Thornton

NASAC Vice Chair
PhD Student, University of North Texas
Research interest: Endocrine disruption, immune function

David Dreier

NASAC Outgoing chair
PhD Student, University of Florida
Research interest: Molecular Ecotoxicology

Sue Robinson

Board of Directors Liaison
Research interest: Ecotoxicology, Ecological & Human Health Risk Assessment

Samreen Siddiqui

SETAC-NASAC Outreach Co-chair
PhD student, Texas A & M University, Corpus Christi, Texas
Research interest:  E
cotoxicology, aquatic toxicology

Meaghan Guyader

Outreach Co-Chair
PhD Student, Colorado School of Mines
Research interest: Environmental Analytical Chemistry, High Resolution Mass Spectrometry, Endocrine Disrupting Mixtures

Kevin Stroski

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MSc Student, University of Manitoba
Research interest: Analytical Environmental Chemistry

Derek Green

Membership Liaison
PhD Student, University of Saskatchewan
Research interest:
 Ecotoxicology, selenium physiology

Niranjana Krishnan

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PhD Student, Iowa State University
Research interest: Ecotoxicology, Risk Assessment

Sivani Baskaran

Science Committee Liaison
PhD Student, University of Toronto
Research interest: Environmental Chemistry


Amanda Buerger

Associate Member
PhD Student, University of Florida
Research interest: Ecotoxicology, public health, microbiome

Heather Ikert

Regional Chapter Representative (Laurentian)
PhD Student, University of Waterloo
Research interest: Aquatic toxicology, physiology, molecular biology

Mariana Cains

Regional Chapter Representative (Ohio Valley) 
PhD student, Indiana University
Research interest: Environmental risk assessment and modeling

Karista Hudelson

Meetings Committee Liaison 
PhD Student, University of Windsor
Research interest: Fate of contaminants in the environment, contemporary and paleo- limnology

Amy Gainer

Publication Advisory Committee
PhD Student, University of Saskatchewan
Research interest: Soil Ecotoxicology

Rachel Leads

M.S. student, College of Charleston
Research interest: Ecotoxicology, aquatic toxicology



Shira JoudanShira

Chemistry Interest Group Liaison
PhD Student, University of Toronto

Research interest:  Environmental Chemistry, organic contaminants, persistence, partitioning, metabolism




Jonathan K. Challis

Graduate Student, University of Manitoba20150724_150626
Research interests: Aquatic chemistry, passive sampling, ecotoxicology, wastewater, pesticides, pharmaceuticals