March 1 was Remembrance Day, a national holiday in the Marshall Islands.
On the morning of that date in 1954, the United States carried out Castle Bravo, the first-ever trial of a deliverable hydrogen bomb, on a man-made island in Bikini Atoll in the mid-Pacific Marshall Islands. It was 6:45 a.m. Sunrise.
Bravo’s explosive power turned out to be 15 megatons, the equivalent of 15 million tons of TNT, more than double what had been expected, and the largest nuclear test in U.S. history — almost 1,000 times more powerful than the bombs dropped on Hiroshima and Nagasaki.
Original projections suggested that Bravo might create a cloud of radioactive fallout 15 miles wide stretching into the atmosphere. Instead, a fireball brighter than the sun blasted 10 million tons of vaporized coral, sand and water into a 100-mile-wide radioactive plume boiling 130,000 feet into the stratosphere.
Five hours after detonation, a mist of radioactive particles began falling on Rongelap Atoll, 120 miles to the east of Bikini. That radioactive mist turned heavier around 1 p.m. and continued for hours. Fallout covered the trees and the flowers and the fruit, the roofs of houses and the beach along the lagoon. Rain fell briefly late in the afternoon, dissolving the radioactive ash on the roofs and sluicing it down drains and into the household water barrels. Rainwater carried the ash from the tin roofs into the island’s communal water supply.
The children playing along the beaches all day had been rolling in fallout. They were tired and thirsty by the time the rain ended, and they drank the radioactive water. So did some of the adults. For many, radioactive white limestone dust was held fast by the coconut oil that islanders used in their hair.
The women of Rongelap regularly wore dresses; men wore pants, but usually no shirts. Adults wore sandals or went barefoot. Children were always barefoot, and the youngest wore no clothes at all. In the heat and humidity that day, they perspired, and as the fallout came down it stuck to their hair and to their bodies, gathering particularly at the folds of their necks.
On parts of the island, the fallout was an inch and a half deep on the ground. When the moon broke through the clouds that night, the white powder glowed like snow. On parts of the island, the fallout was an inch and a half deep on the ground. When the moon broke through the clouds that night, the white powder glowed like snow.
Two days later, U.S. personnel took 82 Marshallese from Rongelap and the nearby Ailingnae atoll to a U.S. Navy base on Kwajalein, another atoll in the Marshall Islands. The Navy doctor supervising their examinations found two-thirds of the Rongelap people suffering loss of appetite, nausea and vomiting, and a majority felt itching and burning of exposed skin, all signs of exposure to radioactive materials.
The people of Rongelap were returned to new homes on their beautiful atoll by the United States in 1957, but left again in 1985 after finding continued radioactivity in the contaminated environment, which made locally grown food unsafe. Only security people live there now.
A 2019 study by Columbia University researchers found that levels of radioactive contamination on the island in northern Rongelap Atoll most affected by nuclear testing still exceeded the levels of radioactive contamination more recently found at Chernobyl, Ukraine, and at Fukushima, Japan.
Castle Bravo was carried out 70 years ago this month, but there is reason beyond the anniversary to remember this story.
A half-century ago, I went to Bikini and Rongelap, accompanying an American medical team that every year since 1954 has examined the exposed Rongelap Marshallese who are still alive. What I learned and saw on that trip contributed to my determination to keep reminding people of the danger of nuclear weapons. To me, one of the best ways to understand the potential long-term danger of nuclear warfare, and to realize why any use of such weapons must be deterred, is to replay what happened at Rongelap and imagine it occurring wherever you live.
Had an equivalent H-bomb exploded near the ground in D.C., the fallout might have extended as far as New York, blanketing thousands of square miles and affecting millions of people — leaving that area “contaminated to such an extent that avoidance of death or radiation injury would have depended upon evacuation of the area or taking protective measures,” according to the Atomic Energy Commission’s “The Effects of Nuclear Weapons,” published in 1962.
