Deborah Swackhamer talks to Kathryn Lees and Neil Withers about water pollution and her dream to sing jazz in piano bars.

Deborah Swackhamer is professor of environmental chemistry at the University of Minnesota, US, and chair of the editorial board of the Journal of Environmental Monitoring. Her work focuses on water pollution, in particular, on the chemical and biological processes that control the fate of toxic organic contaminants in the Great Lakes of North America.

What inspired you to become a scientist?
As a child, I spent my summers in Canada. Our family had a summer cottage on a lake and it was so pristine and beautiful - I thought everyone had lakes like that! At college, I studied math but took a writing tutorial on water chemistry. This grabbed my interest and I switched majors to focus on environmental chemistry.

What is the focus of your research?
When I was a graduate student I saw the Great Lakes for the first time - I was stunned by their size and beauty. As a result, I spent my graduate work understanding the chemical behaviour of the Great Lakes and, ever since, I've focussed on water chemistry programmes of the Great Lakes basin. Because the Great Lakes act like fresh water oceans, you can understand global processes by studying them. They're also easily accessible and urbanised - 42 million people live in the basin so they're reasonably polluted.

What are the main pollutants in the Great Lakes?
There are still 'legacy pollutants' such as polychlorinated biphenyls (PCBs) and DDT coming from atmospheric deposition as well as phosphorus and nitrogen from agriculture and sewage. However, the new problem is with endocrine disrupters. We know little about where they're coming from but we know they're causing oestrogenic effects. At present, they are impacting fish and birdlife but we are not sure if they are affecting people who are drinking the water.

What is the greatest threat to the Great Lakes?
In addition to the chemicals, biologically, there are close to 200 invasive species and a new one is added every eight months. The impact on food webs and ecology could be enormous. However, a dominant factor is the physical threat of global climate change. It affects how chemicals behave in the environment and it drives change in an ecosystem too. Everything is interrelated.

Which species make good biomonitors in the Great Lakes?
A coho salmon lives for three years and grows to one metre so they take up a lot of chemicals. They're also easy to catch and analyse so they give you a good sense of what's in the water. If you're looking at endocrine disruptors then putting caged fish from the lab in the wild can be more effective, because you know their hormones prior to their exposure.

What are the main influences of where a particular pollutant will end up?
Luckily, it's pretty easy to predict that sort of thing from chemical structure. You can predict a chemical's behaviour by knowing two things: its aqueous solubility and its vapour pressure. Its solubility tells you whether it will be in fish or our food supply and its vapour pressure and Henry's law constant tells you whether it will end up in soil, water or air. Finally, you can use the structure of the chemical to see if it will break down or not. We know quite a bit about which bonds are easy to break or metabolise in animal systems.

You sometimes get featured on news programmes, how important is it for scientists to be a voice in the wider media?
It is absolutely critical. We often say the media doesn't ask good questions, but if that's the case it's because we're not communicating well enough with them. It's our responsibility to make sure that what we do is translated appropriately to the media and the general public. Otherwise, others will do it for us and will do it poorly. It's very important that scientists who deal with real world issues inform the decision makers too.

Do you have any involvement with politicians?
We often get asked our opinions on things, but there's a fine line between advocating for a policy and informing a policy. Many scientists say 'No, I shouldn't even talk to a decision-maker!', but others advocate very strongly. I think it is our role to speak out when people are misusing science to set policy. I'm not sure it's my role as a scientist advocate for a policy - but it's certainly my role to advocate for the truth.

Many of the pollutants you mentioned are of great use to many people - how can we find a balance?
Part of the problem is that our regulatory systems for evaluating chemicals are not rigorous enough. If you add something to a soap powder to make it an improved detergent, there are many things you could use. Typically, the least expensive product is added but these additives may be oestrogenic in the environment. The US Toxic Substances Control Act (TSCA) was meant to regulate toxic compounds, but they have allowed many harmful chemicals through their regulatory 'filter'. The EU is moving towards a more stringent filtering process with REACH. We need better modelling tools for predicting toxicity and environmental behaviour so that we can design chemicals that will benefit society and not hurt the environment.

If you weren't a scientist what would you do?
My second love is singing. If I could wave a magic wand, I would sing jazz in a piano bar. I'd have to find someone who could play the piano though!