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.

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.

We are all musicians in a great human orchestra, and it is now time to play the Save the World Symphony. You are not required to play a solo, but you are required to know what instrument you hold and play it as well as you can. You are required to find your place in the score. What we love we must protect. That’s what love means. From the right to know and the duty to inquire flows the obligation to act.

As currently written, the laws require certain manufacturers and users of such chemicals to report any and all environmental releases-either accidental or routine-to air, water, or soil. The Toxics Release Inventory is the main registry of such events, and it is available to the public through the Environmental Protection Agency. It is hardly comprehensive. Toxic emissions reported to the federal government are thought to account for only 5 percent of all chemical releases.

I have come to believe that extracting natural gas from shale using the newish technique called hydrofracking is the environmental issue of our time. And I think you should, too.

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.

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.