Science Update - Mercury Pollution and Public Transport

Bob - This week the topic is climate change, where all the news seems to be bad. And in fact I'll bring you some bad news later about how climate change may be leading to an influx of mercury in the environment. But first, some good news. We all know that taking public transportation over driving is the right thing to do as far as the environment is concerned. But new research suggests that, in some cases, what's good for the environment may also be good for you.

Chelsea - It's an old debate that's been rehashed countless times: Train commuters claim that their ride is less stressful because they don't deal with traffic; drivers swear they're more relaxed because they're in control. Now new research on New York commuters supports the train riders' side. Environmental psychologist Richard Wener of Polytechnic University in New York and his colleagues asked commuters about their psychological states before and after commutes.

Richard - And what we found was that train commuting was significantly less stressful than car commuting, that it seemed to be largely because it was perceived to be significantly less effortful and also more predictable.

Chelsea - Wener says this predictability is key, because it means people can relax knowing they'll get to work and back home on time. Of course that requires that the commuter trains run more or less on schedule, something that's not true in every city. He adds that the effects of stress are not only psychological but also physical, and the daily commute is a potentially significant but still poorly understood contributor to people's stress levels.

Bob - Thanks, Chelsea. Wildfires raging at unprecedented intensities in the north may be unleashing massive amounts of mercury into the environment. The mercury has accumulated harmlessly over thousands of years in the soils of wetlands, particularly in a type of soil called peat in northern North America. But Michigan State University ecologist Merritt Tueretsky says that in just a few decades, forest fires in these regions have more than doubled in size-a result of global climate change.

Merritt - Forest fires don't just burn forests. And our data show that when peat layers within boreal wetlands burn, it releases very large quantities of mercury into the atmosphere.

Bob - She says the mercury could disperse over long distances and find its way into the food chain, where it could eventually reach animals and people.

Chelsea - Thanks, Bob. That's all for this week. Next week we'll bring you a piano piece composed by Mount Etna. Until then, I'm Chelsea Wald.

Bob - And I'm Bob Hirshon, for AAAS, The Science Society.