There is a plaque attached to the Golden Gate bridge, in San Francisco, dedicated to the life and work of a lady whose unswerving belief in the natural world led her into controversy and fame. Conservation and ecology are vitally important in the world today, but were not always so. At least, not before the life's work of this shy, retiring little girl, who loved to explore the local woods and countryside in the early 20th century.

She was the youngest of three children by a full seven years and a loner who loved to write about what she saw and felt. In later life, an editorialist was to say about her – "A few thousand words from her and the world took a new direction." She was to become one of America's truly great nature writers, putting pen to paper from an early age.

Born on 27 May 1907, in Springdale, Pennsylvania – to an insurance salesman dad and schoolteacher mom - her passion for the pen was apparent from an early age, and she was first published in the St. Nicholas literary magazine for children.

Her persuasive and evocative writing style won her a national story competition at the age of ten, and she carried on writing through adolescence, submitting poetry to periodicals. She was a shy girl, plain in looks, and a keen student. It seemed logical for her to study for an English major at Pennsylvania College for Women, despite her fascination with the environment; yet, for Rachel Louise Carson, the whole course of her life was to change.

In junior year, her sense of wonder for nature was re-awakened by a biology course, and she switched majors, to zoology, giving a solid foundation of scientific knowledge to what had been a childhood passion. She graduated magna cum lauda in 1929, with one of the best degrees of her year, going on to study at the Woods Hole Marine Biological Laboratory, and achieving her masters degree in zoology at Johns Hopkins University in 1932.

For a few years, she taught at the University of Maryland. Her time at Woods Hole had made her a devotee of sea-life, and in 1935 she began writing radio scripts for the old Department of Fisheries. This was for a science series called "Romance Under the Water", and her writing style made it an enormous favourite with the public.

"Ray", as friends knew her, had soon impressed the department enough to offer her a full time job as junior aquatic biologist, the first female biologist ever to be employed by them. The pay wasn't great, so she supplemented it with writing, contributing feature articles to the "Baltimore Sun," among many other publications.

Her two loves in life – writing and the natural world – complemented each other so well that her first publication in a national magazine – a piece called "Undersea," appeared when she was 30. She worked on science in the daytime, writing about it at night. Her own favourite book was her first, "Under the Sea-Wind," published in 1941. Although it did not receive much public attention at the time, fellow scientists and critics were full of praise.

This was an era when two basic beliefs were central to people's thinking. Firstly, that the curing of diseases like smallpox had eradicated environmental hazards, and secondly, that technological advance was worth the sacrifice of some aspects of the natural world. This was not Rachel Carson's feeling, however.

From this time on, she began to write more openly on the issue that would bring her lasting fame: the need for environmental awareness. She wrote pieces on conservation, turning government research into prose, and she rose to become editor of all publications for what was now the Fish and Wildlife service, at a youthful 42, in 1949.

At that time, she was working on a project that – having been rejected by 15 magazines (including National Geographic!) – was to be serialised in the New Yorker as "A Profile of the Sea", going on to be published as the book "The Sea Around Us" in July 1951. It was a best-seller, winning the John Burroughs Medal, topping the best seller list for 86 weeks and selling over 200,000 copies in a year!.

Suddenly, she'd become a national celebrity. "Under The Sea-Wind" was re-issued, and she had two best sellers on the New York Times list. She became a full-time writer in 1952, more confident in speaking out about her concerns for the natural world. Though not a likely candidate as a crusader, she nonetheless felt she had to act.

It had been as early as 1945 that she'd first become alarmed about the new "wonder" pesticide, DDT, and when a friend's bird sanctuary was decimated by arial spraying of the substance, she really began to investigate. Ever greater use was made of DDT in the forties, as a miracle cure for insect borne diseases.

It had first been produced in Germany in 1874, though it was fifty years later that Swiss chemist Paul Muller discovered its insecticidal properties. It seemed the perfect solution to insect problems from mosquitoes to Colorado beetles, and was gratefully taken up.

Carson was especially concerned about the so-called "pest" and "predator" programs, because no thought was given to the poisonous effects on wildlife in general. Her article on this was rejected by the Readers Digest in 1945, and even more lethal compounds – dieldrin, parathion and heptachlor for example, began to be sanctioned by the government for commercial manufacture and public use.

"The more I learned about the use of pesticides, the more appalled I became. I realised that here was the material for a book. What I discovered was that everything which meant most to me as a naturalist was being threatened, and that nothing I could do would be more important." She later recalled.

She knew that her fame and eloquence on the subject of the environment would attract much scientific support, but the major publications were reluctant to pursue it, perceiving it as too gloomy for public consumption. Undeterred, she continued to research the matter with passionate intensity. She never once asked for a complete ban on chemical agents – except for DDT – recommending only that caution be exercised, until the full effects were known.

She released another book, The Edge of the Sea, in 1955, and she began to warn of pesticide poisoning of rivers and soils, but still people didn't seem to be listening. Her frustration ended in 1957, when a mosquito-control campaign in Duxbury, Massachusetts, led to an enormous loss of local wildlife. A vigorous war against the fire ants in the Southern States also did tremendous harm. Suddenly, the public began to feel alarmed, and questions began to be asked.

In 1958, she signed up to write a series of pieces for the New Yorker and a book about the damage pesticides were doing to the ecology. A huge public outcry developed against the use of aminotriazole on cranberries, leading to a ban on the marketing of the fruit just before Thanksgiving of 1959. Over the next few years, her investigations – minutely studying the reports of other scientists as well - revealed horrifying statistics.

Evidence surfaced that the totally indiscriminate use of pesticides all over America damaged the health of creatures as diverse as fish and man himself. As it passed through he food chain, untold millions of songbirds died. There was a savage irony, in 1960, after she'd spoken of a possible link between DDT and human cancer, when she herself was diagnosed as having the disease.

She was the one who brought the starkly grim reality of the dangers to a head, with but a few sentences "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 Spring without voices. On the mornings that had once throbbed with the dawn chorus of scores of bird voices there was no sound; only silence lay over the fields and woods and marsh."

Her book Silent Spring was serialised in the New Yorker in 1962. Even before it was published, she was besieged by lawyers representing giants of the chemical industry, like Monsanto and American Cydanamid. These were supported by the Agriculture Department, and in the press, a "smear" campaign against her took off, with accusations varying from her being simply "hysterical" to acting under communist influences!

Despite her family commitments – after the deaths of her father and a sister, the unmarried Rachel supported her mother – and her own fragile health, she stood firm, resolutely maintaining her campaign. As the year progressed, her attackers retreated. Silent Spring was a runaway best-seller, and the American public were angry.

She was, within a few months of the book being published, far and away the most controversial – and most admired – woman in America. In May 1963, she appeared on national television, to an audience of 12 million viewers, with government scientists. Avid watchers heard her say about pesticides: "We have heard a great deal about their safety, but very little about the hazards, very little about the failures." Those scientists tried to evade the issue, while chemical industry spokesmen talked of "Spurning science plunging the world into a new Dark Age of pestilence and disease," but she had them on the run.

Later in the 1960's, a UK study of 1000 wild bird corpses confirmed that pesticides had played a major part in their deaths, and that the reduction in the fox population could be directly attributed to their having eaten poisoned birds. Many bird species, like the robin, were in serious decline – a process which, strangely enough, reversed itself later as stricter controls on pesticides were introduced.

She appeared, calm and dignified, before a federal scientific advisory committee set up by President Kennedy in 1963, testifying about her findings. Sadly, she didn't live to see the full impact of her life's work, or her book, for the cancer finally claimed her on April 14th, 1964, in Silver Spring, Maryland. It was 1972 before DDT was banned in the USA.

She was no banner-waving zealot in her role as the world's first real "Eco-warrior," but a softly spoken, 55-year-old ex-government scientist with a genuine passion for the natural world. In a letter to a friend – written in 1962 – she wrote: "The beauty of the living world I was trying to save has always been uppermost in my mind – that, and anger at the senseless brutish things that were being done. I have been bound by a solemn obligation to do what I could – if I didn't at least try, I could never be happy again in nature. But now I can believe that I have at least helped a little. It would be unrealistic to believe one book could bring a complete change."

She may have been right, but Silent Spring became the cornerstone of the growing ecology movement around the world. As one of America's greatest nature writers, she inspired generations of activists. She will never be forgotten. Rachel Louise Carson - without doubt a woman of whom it can surely be said - "She was America"s 'Green' First Lady".

      Tony Leather is a UK writer, published fairly widely around the world, both in print and online. Only writing seriously for about three years now, he hopes to establish a name and reputation as a writer, and even one day earn a living from it. He appreciates comment from readers about his work, and can be contacted at tony@stables.worldonline.co.uk Your comments help him to improve his writing, he says, so don't be shy!