We can decide that the presence of cancer-causing substances in our air, water, and food is too expensive. A 2009 study, for example, has found that coal miners in Appalachia costs the region five times more in premature deaths, including from cancer, than it provides to the region in jobs, taxes, and economic benefits. In California, the production and use of hazardous chemicals cost the state $2.6 billion in 2004 alone in lost wages and health-care expenses to treat workers and children with pollution-linked diseases.

Drink a bottle of French water and then step into the shower for ten minutes and you've just received the exposure equivalent of drinking a half gallon of tap water. We enjoy the most intimate of relationships with our public drinking water, whether we want to or not.

Here in the United States, a study of nearly 700 women in California showed an increased risk of fetal death among babies whose mothers lived near crops when certain pesticides were sprayed. The largest risks were found among pregnant women exposed during the critical first trimester and among those who lived in the same square mile where pesticides were used.

The study of how substances alter gene expression is part of the field of epigenetics. Some chemical exposures appear to turn on and turn off genes in ways that disregulate cell growth and predispose for cancer. From this perspective, our genes are less the command-and-control masters of our cells and more like the keys of piano, with the environment as the hands of the pianist.

I have always been a big advocate of tap water-not because I think it harmless but because the idea of purchasing water extracted from some remote watershed and then hauled halfway round the world bothers me. Drinking bottled water relieves people of their concern about ecological threats to the river they live by or to the basins of groundwater they live over. It's the same kind of thinking that leads some to the complacent conclusion that if things on earth get bad enough, well, we'll just blast off to a space station somewhere else.

By 1990, the EPA had tallied up 32,645 sites of past chemical waste dumping in need of cleanup. Some of these are actual waste landfills, but many are former manufacturing sites where drums full of chemicals have been simply abandoned. The names of the most notorious appear on the EPS's National Priorities List. These are the so-called Superfund sites, names for the super fund of money put together by Congress in 1980 to clean them up. In 2009, the Superfund list contained 1,331 sites.

We can decide that the presence of cancer-causing substances in our air, water, and food is too expensive. A 2009 study, for example, has found that coal miners in Appalachia costs the region five times more in premature deaths, including from cancer, than it provides to the region in jobs, taxes, and economic benefits. In California, the production and use of hazardous chemicals cost the state $2.6 billion in 2004 alone in lost wages and health-care expenses to treat workers and children with pollution-linked diseases.