As the Japanese government widens the exclusion zone around the Fukushima plant, it is worth remembering that not everyone can stay indoors or leave the area.
The workers dealing with the crisis have a monumental responsibility — which could leave them with lifelong health problems, or even kill them.
It has been reported that two workers have been missing at Fukushima since Friday, the day the quake and tsunami struck. They have not been named but Japan's nuclear safety agency said they had been in the turbine area of reactor four.
After most emergency workers were evacuated earlier, about 50 remained inside the plant.
They have had to perform emergency tasks in extremely difficult conditions — battling to keep the nuclear reactors from entering meltdown and fighting off outbreaks of fire.
Dressed in protective gear, they have had to pump seawater into the failing reactors to try to keep them cool, and all their work has been carried out in conditions of escalating radiation.
“I'm fairly sure the workers inside are being subjected to high levels of radiation,” said Rianne Teule, an anti-nuclear campaigner for Greenpeace.
“The information we have is they are working in 15-minute shifts to reduce exposure.”
Japanese authorities have not released information about maximum doses of radiation workers will be exposed to, or whether they will be replaced.
But with a finite pool of workers available, unless the problem is brought under control, they will ultimately be exposed to dangerous doses — or the work will be abandoned.
There has been speculation that volunteers from other plants and retirees might be called in.
Such calculations are familiar to those who worked at Chernobyl.
After that catastrophe, a group of older experts travelled to the site to offer help on the principle that long-term consequences such as cancers, which emerge years later, would matter less to them.
In the aftermath of the disaster, the earliest responders were exposed to doses of radiation so large that many of them died in weeks.
Later, Soviet authorities flew in hundreds of thousands of workers to aid the clean-up. Some of them worked for as little as 15 seconds before they had reached the maximum dose.