Concern in Tokyo Over Radiation in Tap Water

Twelve days after the magnitude-9 earthquake and tsunami crippled the Fukushima Dai-ichi nuclear plant, the crisis reached Japan's dinner tables -- and then its taps. March 23, 2011, was the day the disaster stopped being something that happened 140 miles north of Tokyo and became something in the water.

Officials announced that Tokyo tap water contained 210 becquerels per liter of iodine-131 -- more than twice the recommended limit of 100 becquerels for infants, though below the 300-becquerel limit for adults. Parents were advised to stop giving tap water to babies; older children and adults were told there was no immediate risk. Chief Cabinet Secretary Yukio Edano tried to steady nerves, saying that even a year of drinking the water would not affect people's health. Experts noted that iodine-131 decays fast -- half of it gone every eight days -- and that the spike was likely wind-driven, a shift in the breeze from the plant toward the capital. In Tokyo, bottled water sold out.

The water scare was only one thread of a terrible day's news. Radiation had seeped into vegetables, raw milk, and seawater; broccoli joined the list of tainted produce, and the United States blocked imports of Japanese dairy and other food from the region. In an area about 40 kilometers northwest of the plant, one leafy green -- kukitachina -- measured 82 times the government's limit for radioactive cesium and 11 times the limit for iodine.

At the plant itself, black smoke billowed from Unit 3, forcing another evacuation of workers; the cause was unknown, and there was no corresponding radiation spike. There had been progress -- power restored to all six units, lights on at Unit 3 for the first time since the disaster -- but cooling the reactors remained intermittent, disrupted by rising radiation, pressure spikes, and overheated storage pools.

The human ledger kept growing: more than 9,400 dead, over 14,700 missing, hundreds of thousands in shelters without heat or medicine. The government put the cost at up to $309 billion -- already, it said, the most expensive natural disaster on record.

Fifteen years on, March 23 reads as a case study in crisis communication under radical uncertainty: officials balancing candor against panic, parents making decisions with incomplete information, and a public learning -- in real time -- the difference between a limit designed for a lifetime of exposure and a spike measured in days. The fear that day was real. The physics, as it turned out, was on Tokyo's side.