"There was once a town in the heart of America where all life seemed to live in harmony with its surroundings … Then a strange blight crept over the area and everything began to change ... There was a strange stillness … The few birds seen anywhere were moribund; they trembled violently and could not fly. It was a spring without voices. On the mornings that had once throbbed with the dawn chorus of scores of bird voices there was now no sound; only silence lay over the fields and woods and marsh."

Silent Spring, 1962

This week marks what would have been Rachel Carson's 100th birthday. I'm embarrassed to write that until reading an article about her in last week's New Yorker, I didn't know that she was a National Book Award winner. Or that at the end of the last millennium Time magazine named her one of the most influential people of all time. In fact, as it turns out, I owe quite a bit of my environmental awareness to a woman, who until a week ago, I hadn't even known existed.

A former biologist at what is now called the Fish and Wildlife Service, Rachel Carson is best known for a series of articles called Silent Spring, written for the New Yorker in 1962. Essentially a critique of the USDA's pesticide use, the book spearheaded environmental activism and eventually triggered the creation of the Environmental Protection Agency, the Endangered Species Act, and the banning of pesticides like DDT.

Carson died from breast cancer two years after writing Silent Spring. But her effort to expose the dangers of environmental toxins continues through organizations like the Silent Spring Institute (http://www.silentspring.org/) in Newton, Massachusetts, which studies the relationship between women's health and exposure to toxins. This week, I'm remembering that every one of us owes our ecovalues to Muir, Emerson, Carson, and all the others who came before us. It's up to us to continue where they left off.