Able explodes at Bikini AtollJuly 1, 1912: David Brower is born in Berkeley, Calif. Brower goes on to lead the Sierra Club and help bring the group to national prominence, and later founds both Friends of the Earth and the Earth Island Institute.

July 1, 1941: Mammoth Cave National Park is created in central Kentucky. One of the most extensive systems of underground caverns in the world, Mammoth Cave was vulnerable to commercial exploitation until it received its park designation. Steven Bishop, an early cave explorer and guide, called it "a grand, gloomy and peculiar place."

July 1, 1946: The U.S. detonates an atomic weapon, codenamed "Able," at Bikini Atoll in the Pacific in the first peacetime nuclear test (at right). The natives of Bikini island are relocated, and return in 1974 when the island is pronounced safe from radiation. But additional tests find a lingering radioactive health risk, and the island is evacuated a second time in 1978.

July 1, 1996: A groundbreaking book on endocrine-disrupting chemicals is published. "Our Stolen Future," by scientists Theo Colborn and Pete Myers and journalist Dianne Dumanoski, documents the ability of some organic chemicals to impact reproduction and even change the gender of both wildlife and humans.

July 1, 1999: The Edwards Dam in Augusta, Maine, is removed. Since the river was initially dammed in 1837, the upper Kennebec River is blocked as a spawning grounds for Atlantic salmon, river herring and shad. All three fish species are found upstream from the dam site a year later.

July 1, 2000: China bans the manufacture and use of leaded gasoline. Extensive research has linked the burning of leaded gasoline to brain damage and declining IQ levels in children.

Photo: National Park Service

This feature is compiled by Peter Dykstra, an MNN contributor and publisher of Environmental Health News and The Daily Climate.