Nuclear radiation doused corals, but they didn’t get cancer
Bikini Atoll could hold clue to DNA defense
It has been more than 60 years since the United States dropped 23 atomic bombs on Bikini Atoll, a small ring of sand and sea teeming with corals in the Pacific Ocean.
Scientists are trying to figure out why long-term radiation ex- posure from the nuclear tests on the area, about 2,500 miles southwest of Hawaii, hasn’t caused the marine invertebrates to develop cancer.
Radiation exposure is known to cause DNA mutations that can lead to cancer in humans and animals alike. Corals are particularly prolific, living thousands of years and growing up to 30 feet long.
“We would expect them to get cancer at some point,” said Elora López, a biology graduate student at Stanford University and a member of the research team that studied the coral.
Yet somehow, the fast-growing coral in Bikini Atoll — and other living things in the area — appear unharmed by the high levels of radiation that saturate the region, even as cancer rates among residents on the Marshall Islands remain elevated, Lopez said.
“We know the mystery is worth answering because corals must be doing some things to protect their genes that we cannot,” said Stephen Palumbi, a professor of marine science at Stanford University, who led the research. “By understanding how corals could have recolonized the radiation-filled bomb craters, maybe we can discover something new about keeping DNA intact.
“The terrible history of Bikini Atoll is an ironic setting for research that might help people live longer.”
The research team is examining the effects of radiation on other animals and plants on the atoll and in the surrounding seas. Palumbi said nurse sharks with only one dorsal fin instead of two have been spotted, possible evidence of mutations caused by radiation exposure.
Researchers witnessed seemingly healthy crabs feeding on coconuts contaminated with a radioactive isotope from groundwater and plan to study that species in the future.