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.

Between the late 1950s and the late 1980s, more than 750 million tons of chemical wastes were discarded.

Besides, the sense of safety offered by bottled water is a mirage. It turns out that breathing, not drinking, constitutes our main route of exposure to volatile pollutants in tap water, such as solvents, pesticides, and byproducts of water chlorination. As soon as the toilet is flushed or the faucet turned on-or the bathtub, the shower, the humidifier, the washing machine-these contaminants leave the water and enter the air. A recent study shows that the most efficient way of exposing yourself to chemical contaminants in tap water is to turn on a dishwasher.

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.

Indeed, the quantity of PCBs still in use plus the quantity still languishing in waste dumps exceeds the total amount that has already escaped into the general environment. Without a program to recall and contain them, semivolatile PCBs will continue to insinuate themselves into the food chain for decades.

In the world outside this glass room, songbirds are feeding and resting in the trees. Some will take off tonight and not land until they reach Venezuela. Sandpipers, plovers, and broad-winged hawks have already left for Patagonia and Panama. Bats are headed for caves in Kentucky and Tennessee. Out in the Atlantic, humpback whales pass by on their way to the Caribbean. Even now, Canada geese are honking toward us from Quebec. It is a good day for the beginnings of journeys.Every time I look at you, I think, Now I cannot die.

I'm beginning to perceive motherhood as a long, slow letting go, of which birth is just the first step.