Celia Chen, a principal investigator in the Dartmouth Toxic Metals Superfund Research Program and biology professor, is an expert in ecotoxicology and aquatic ecology. She has researched the effects of metal contaminants on aquatic food chains both in freshwater and estuarine ecosystems over the last 15 years. Last month, she represented Dartmouth as a non-governmental organization at a United Nations conference. There, she advocated that scientists be involved in the implementation of the Minamata Convention on Mercury, a United Nations treaty adopted in 2013 that aims to protect human health and the environment from the hazardous effects of mercury. At the meeting, Chen joined delegates of signatory countries of the treaty.
How did you become interested in the field of ecotoxicology?
CC: I went to Dartmouth, and I was a biology major modified with environmental studies. Then I got a masters in biological oceanography. And then I got a Ph.D. in aquatic ecology, which was in freshwater. So, I sort of have been working in aquatic systems most of the time. I became part of a submission for a big grant for a program called the Dartmouth Toxic Metals programs. We applied for a program grant in 1994, got it, and we have continuously funded that by going through these competitive resubmissions for a new grant every five years, and we’ve had it now for almost 23 years. We study mostly arsenic and mercury because those are two of the most important priority pollutants in the U.S., and mercury is a perfect one to study for someone like me because the main exposure route for humans is fish consumption.
How was the Dartmouth Toxic Metals Superfund Research program developed?
CC: The program looks at the various chemicals in the environment and how they affect human health as well as environmental health. The National Institute of Environmental Health Sciences funds this program within it called the Superfund Research Program. There are about 15 to 20 institutions around the country like Dartmouth, and we all study chemicals that are found in contaminated sites, which are called the superfund sites. The superfund sites have lots of different chemicals. We don’t necessarily study the sites. We study the chemicals found in those sites and how they affect biological processes and human health. Some of the studies look at human populations, and some of them look at molecular science and how they affect molecular or cellular processes.
Within that program, we have four projects. Two of them are what we call biomedical projects. They look at effects on human health processes. And then two are non-biomedical. My project is a non-biomedical project because I study aquatic ecosystems. The other non-biomedical project here in our program is one by [biology professor] Mary Lou Guerinot . She studies the uptake of arsenic in rice. Arsenic is a problem in rice grown in certain areas, and so her study is really plant genetics.
Of two biomedical studies, one looks at the populations of humans and how arsenic exposure affects early outcomes. The other biomedical project in our program is the effect of arsenic on lung function because arsenic has been shown to be related to respiratory kinds of problems. We’re really different kinds of scientists, but we’re unified by the fact that we all study metals, and we have a lab that is also funded by this big program that analyzes our samples.
How was the Minamata Convention adopted and what do you hope comes out of the Minamata Convention?
CC: The reason it’s called the Minamata Convention is because of the realization of Minamata disease, which was discovered in a population in Minamata, Japan, where people had been eating a lot of seafood, and over time there was a recognition that this chemical plant built in the 1950s had started discharging all this mercury waste into Minamata Bay. Nobody realized then that mercury gets into the water, and then into fish, and each level of the food chain gets higher and higher. It’s biomagnification. So people didn’t realize it — they found people were getting really sick and dying, and there were all these birth defects. And then they started to realize that the disease was showing up in other cities besides just Minamata, but the treaty was called that in honor of those people who were first affected.
I think in the early 2000s, they started to recognize globally that there was this problem with mercury. Scientists have known it for a long time, but there was no collective will to have a treaty and that was in part because George W. Bush was our president, and he was not an environmental guy. But there were other countries that were getting very interested in it. And then it wasn’t until Barack Obama became our president, and he had always been interested in the mercury issue. He was a senator before, and he actually had introduced a mercury export ban in the U.S. because of this concern over mercury. When he came into office as president, he then was the impetus for the U.S. to say that we are interested in an international treaty. I’ve talked to other people who were very involved in the treaty and negotiations over these years, and they said that had Obama not been the president, we wouldn’t have this treaty right now, which I think is interesting because hardly anyone knows that Obama had anything to do with mercury.
How is your research related to classes you teach at Dartmouth?
CC: My research is in estuaries, which is one of the systems I teach in marine biology and ecology. I, often at the end of my course, talk about applied issues in marine systems. So sometimes, I will do one lecture on my research. I think it’s really from having been trained in marine science that is why I can teach marine biology, and I love teaching that course. And I also teach the biology foreign studies program, in the coral reef ecology course. The fact that I teach in Costa Rica has made me want to think about doing research down there — there’s an opportunity to go look at the world of mercury science where we have a lot of research that has been going on in the temperate zone. But there isn’t research that has been done in the tropical areas. Since I go to the Caribbean, I started to collect samples just this last year, so it’s teaching that course has given me opportunity to expand my research to that system. So, it’s both ways. One is that I bring my research to one of my courses, and the course has allowed me to think about that set of issues down there.
Are you currently doing research on any other topics?
CC: Most of my research has something related to mercury, but one project I’m involved in is on the evaluation of economic valuation of small streams. Should we, in our communities, protect our water streams? What do they give us? What do people think? So the economic valuation has to do with what people value and the protection of resources that has to do with whether people value them enough to protect them. I’m on another project that has to do with ALS, the Lou Gehrig’s disease. There are a couple of neurologists who are interested if any of the chemical predictors and algal blooms seem to predict the incidents of the Lou Gehrig’s disease. So we’ve been looking at exposure to mercury, cyanotoxins, which are blue-green algal toxins. This has a little bit to do with mercury, but it has a lot to do with other stuff too. I think that’s one of the coolest things about getting to work in science — you can work on as much as your comfort zone allows you to, and getting to collaborate with people in other areas of expertise is just cool because I constantly am learning from people.
This interview has been edited and condensed for clarity and length.
