0:00:06.841,0:00:09.871 In 1958, Rachel Carson received a letter 0:00:09.871,0:00:13.280 describing songbirds suddenly dropping [br]from tree branches. 0:00:13.280,0:00:16.920 The writer blamed their deaths [br]on a pesticide called DDT 0:00:16.920,0:00:19.920 that exterminators had sprayed [br]on a nearby marsh. 0:00:19.920,0:00:23.660 The letter was the push [br]Carson needed to investigate DDT. 0:00:23.660,0:00:27.700 She had already heard from scientists [br]and conservationists who were worried 0:00:27.700,0:00:32.232 that rampant use of the pesticide [br]posed a threat to fish, birds, 0:00:32.232,0:00:33.862 and possibly humans. 0:00:33.862,0:00:36.920 She began to make inquiries [br]through government contacts 0:00:36.920,0:00:40.356 from her years working [br]in the United States Bureau of Fisheries. 0:00:40.356,0:00:45.501 She asked: “what has already silenced [br]the voices of spring?” 0:00:45.501,0:00:50.784 In 1962, Carson published her findings [br]in "Silent Spring." 0:00:50.784,0:00:53.514 Her book documented [br]the misuse of chemicals 0:00:53.514,0:00:56.374 and their toll on nature [br]and human health. 0:00:56.374,0:01:01.337 "Silent Spring" immediately drew both [br]applause and impassioned dissent— 0:01:01.337,0:01:04.247 along with vicious personal attacks [br]on the author. 0:01:04.247,0:01:10.123 How did this mild-mannered biologist [br]and writer ignite such controversy? 0:01:10.123,0:01:13.773 Carson began her career [br]as a hardworking graduate student, 0:01:13.773,0:01:17.584 balancing her studies in biology [br]at John Hopkins University 0:01:17.584,0:01:18.934 with part time jobs. 0:01:18.934,0:01:22.204 Still, she had to leave school [br]before completing her doctorate 0:01:22.204,0:01:25.274 to provide for her ailing father [br]and sister. 0:01:25.274,0:01:28.314 Carson found part time work [br]with the Bureau of Fisheries 0:01:28.314,0:01:31.964 writing for a radio program [br]on marine biology. 0:01:31.964,0:01:36.054 Her ability to write materials that could [br]hold the general public’s attention 0:01:36.054,0:01:39.314 impressed her superiors, [br]and in 1936, 0:01:39.314,0:01:43.354 she became the second woman [br]to be hired at the Bureau full time. 0:01:43.354,0:01:47.769 In 1941, she published [br]the first of three books on the ocean, 0:01:47.769,0:01:52.165 combining science with lyrical meditations[br]on underwater worlds. 0:01:52.165,0:01:56.514 These explorations resonated [br]with a wide audience. 0:01:56.514,0:01:59.482 In "Silent Spring," [br]Carson turned her attention 0:01:59.482,0:02:03.824 to the ways human actions [br]threaten the balance of nature. 0:02:03.824,0:02:08.980 DDT was originally used during [br]World War II to shield crops from insects 0:02:08.980,0:02:12.490 and protect soldiers [br]from insect-borne diseases. 0:02:12.490,0:02:17.337 After the war, it was routinely sprayed [br]in wide swaths to fight pests, 0:02:17.337,0:02:19.647 often with unforeseen results. 0:02:19.647,0:02:22.886 One attempt to eradicate fire ants [br]in the southern U.S. 0:02:22.886,0:02:29.060 killed wildlife indiscriminately,[br]but did little to eliminate the ants. 0:02:29.060,0:02:33.170 In spite of this and other mishaps, [br]the US Department of Agriculture 0:02:33.170,0:02:37.096 and chemical companies [br]extolled the benefits of DDT. 0:02:37.096,0:02:41.170 There was little regulation or public [br]awareness about its potential harm. 0:02:41.170,0:02:44.394 But Carson showed how [br]the overuse of chemicals 0:02:44.394,0:02:47.416 led to the evolution [br]of resistant species— 0:02:47.416,0:02:51.746 which, in turn, encouraged the development[br]of deadlier chemicals. 0:02:51.746,0:02:54.330 Since DDT does not dissolve in water, 0:02:54.330,0:02:58.802 she asserted that over time [br]it would accumulate in the environment, 0:02:58.802,0:03:03.101 the bodies of insects, the tissues [br]of animals who consume those insects, 0:03:03.101,0:03:04.841 and eventually humans. 0:03:04.841,0:03:09.907 She suggested that exposure to DDT [br]might alter the structure of genes, 0:03:09.907,0:03:13.727 with unknown consequences [br]for future generations. 0:03:13.727,0:03:17.172 The response to "Silent Spring" [br]was explosive. 0:03:17.172,0:03:20.542 For many people the book [br]was a call to regulate substances 0:03:20.542,0:03:22.942 capable of catastrophic harm. 0:03:22.942,0:03:26.802 Others objected that Carson [br]hadn’t mentioned DDT’s role 0:03:26.802,0:03:30.432 controlling the threat insects [br]posed to human health. 0:03:30.432,0:03:35.285 Former Secretary of Agriculture [br]Ezra Taft Benson demanded to know 0:03:35.285,0:03:40.497 “why a spinster with no children [br]was so concerned about genetics?” 0:03:40.497,0:03:44.767 and dismissed Carson [br]as “probably a Communist.” 0:03:44.767,0:03:49.796 A lawyer for a pesticide manufacturer [br]alluded to Carson and her supporters 0:03:49.796,0:03:55.579 as “sinister influences” [br]aiming to paint businesses as “immoral.” 0:03:55.579,0:03:59.099 In reality, Carson had focused [br]on the dangers of chemicals 0:03:59.099,0:04:03.602 because they weren’t widely understood, [br]while the merits were well publicized. 0:04:03.602,0:04:06.008 She rejected the prevailing belief [br]that humans 0:04:06.008,0:04:08.736 should and could control nature. 0:04:08.736,0:04:11.536 Instead, she challenged people [br]to cultivate 0:04:11.536,0:04:16.686 “maturity and mastery, not of nature, [br]but of ourselves.” 0:04:16.686,0:04:20.216 Carson died of cancer in 1964, 0:04:20.216,0:04:23.906 only two years after [br]the publication of "Silent Spring." 0:04:23.906,0:04:28.584 Her work galvanized a generation [br]of environmental activists. 0:04:28.584,0:04:32.324 In 1969, under pressure [br]from environmentalists, 0:04:32.324,0:04:36.046 Congress passed [br]the National Environmental Policy Act 0:04:36.046,0:04:41.559 that required federal agencies to evaluate[br]environmental impacts of their actions. 0:04:41.559,0:04:42.989 To enforce the act, 0:04:42.989,0:04:47.216 President Richard Nixon created [br]the Environmental Protection Agency. 0:04:47.216,0:04:53.566 And in 1972, the EPA issued [br]a partial ban on the use of DDT. 0:04:53.566,0:04:58.254 Long after her death, Rachel Carson [br]continued to advocate for nature 0:04:58.254,0:05:00.934 through the lingering impact [br]of her writing.