Before the 1960s, the media reported sporadically on the environment—often then referred to as the 'ecology' issue.

But Rachel Carson's 1962 book, Silent Spring, which raised deep concerns about the nation's increasing reliance on synthetic pesticides, sparked the United States' modern environmental movement and, in turn, increased media scrutiny of its issues.

Before Silent Spring, some major pollution events, notably the "killer fog" of Donora, Pennsylvania, and the black afternoon smog of major industrial towns such as Pittsburgh and St. Louis, had largely been the limits of media coverage.

"Throughout most of the Sixties, unless a river was on fire or a major city was in the midst of a weeklong smog alert, pollution was commonly accepted by both the press and the general population as a fact of life," wrote David B. Sachsman in the SEJournal, the quarterly publication of the Society of Environmental Journalists...