In 1962, a controversial book about the environmental and human health dangers of chemical pesticides sparked a major shift in public thinking about the environment.

The book was Silent Spring. Its author was Rachel Carson.

To mark the 40th anniversary of "Silent Spring" publication, VOA's Rosanne Skirble visits Rachel Carson's birthplace and explores the life and legacy of a woman many consider the mother of the environmental movement.

In a white clapboard farmhouse in the rolling hills of Pennsylvania lived a little girl. She liked to play in the woods, pick apples in the orchard and draw and write about what she saw.

"These are the very grounds that Rachel Carson walked on as a child. This is the place where she learned to love nature, where she learned to observe nature, where she learned in a very personal and intuitive way that she was a part of nature, All of the human world is a part of the living planet. This is the place where she first developed that love," Vivienne Shaffer said.

We are walking in the Rachel Carson Homestead, the author's historic childhood home. The 65-acre (26-hectare) farm has been divided many times since the Carson family lived here in the early 1900s. Our guide is the Homestead's executive director, Vivienne Shaffer.

"It is possible to come out here on the nature trail and just to sit quietly and imagine that a little girl is going to come walking along carrying her lunch, looking under leaves and trying to find wild flowers and looking up into the trees at the birds and then go skipping off to explore one of the streams running down the hill," she said.

The Carsons lived in this simple, five-room house from 1900 until 1930. None of the objects on display actually belonged to the Carsons, but they tell the story of a humble family.

The Carson house had no indoor plumbing or heat. But there was a piano in the parlor where Maria Carson Rachel's mother gave piano lessons and in Maria Carson's upstairs bedroom stand a small coal stove and an old foot-powered sewing machine.

From her room, young Rachel could see the Allegheny River, read her many books, or play with the broken bits of pottery she creatively turned into a tea set for her dolls.

But visitors also come to the Carson Homestead to learn more about Silent Spring. In that groundbreaking work, Rachel Carson meticulously documented how the excessive use of chemical pesticides was having harmful effects on the natural environment and human health.

Evidence of what life was like before Silent Spring's 1962 publication can be found on display in the Homestead's dining room.

"On the table next to the sea shell there is a spray bottle and an empty box of one of the insecticides that is now illegal to use. And, on one of the posters on the wall in this room there is a picture of a woman spraying DDT over the bed of her sleeping child. It was so widely believe that these chemicals could only harm insects and not have any effect on any other life form that it was promoted as something that was safe to use even around food," Ms. Shaffer said.

DDT was used during World War II to clear islands in the South Pacific of malaria-causing insects, and so protect U.S. soldiers from the often lethal disease.

But DDT also lingers in the environment. Scientists learned that when the chemical enters the food chain, it accumulates in the fatty tissues of animals and humans, causing cancer and genetic damage. This is the alarm Rachel Carson sounded in Silent Spring.

"She felt that it was being overused and she demonstrated in her book that many of the so-called pests that it was meant to destroy were becoming resistant to it. The prevailing understanding of the place of human beings in the world was that man would conquer the earth. That was a phrase that was repeated many times, the conquest of the earth. What Rachel Carson changed by writing Silent Spring, was to bring to the public the understanding that the conquest of the earth is suicide because we are part of earth. We are connected to everything else that lives on the earth. Everything else that lives on the earth is connected to us. And, any place that you rattle the web is going to rattle every other part of the web as well. There was not an understanding of that before Silent Spring," she said.

Silent Spring, with its 50 pages of footnotes, became a best-seller in part because of vociferous attacks on the book and its author by the U.S. chemical industry. But the controversy over the book's findings sparked a public outcry for change in the country's pesticide laws. A scientific committee appointed by President John Kennedy vindicated Rachel Carson and led to a ban of DDT in the United States.

Vivienne Shaffer says Rachel Carson's most enduring legacy is the environmental movement in the United States and in other countries that her book helped to launch.

"There are government agencies that are charged with safeguarding the elements of our environment that are most natural. Those agencies were all created after the publication of Silent Spring. So it is both a governmental responsibility and a public awareness of the importance of carrying out that responsibility to be responsible in the way that we walk on the earth," Ms. Shaffer said.

That is the message that the Rachel Carson Homestead hopes to pass on to visitors like 10-year-old Emily Lutts, whose father grew up just down the street from the Carson house. Mr. Lutts says he often brings his daughter to explore these same woods that attracted a young Rachel Carson so many years ago.

Mr. Lutts: "I think there is a connection that they have something in common. What do you think Emily?"

Emily Lutts: "Yeah!"

Reporter: "Emily, Why do you like Rachel Carson so much?"

Emily Lutts: "Because she is pretty much like me. She loved to play outside, and so do I. I usually spend my time in the summer always outside."

Reporter: "What do you think you'll find today?"

Emily Lutts: "Probably old mushrooms and everything!"