A dose of radiation for health?

Sixteen hundred people died following the Fukushima nuclear accident. But scientists have recently found that none of the deaths were caused by radiation. “It was the fear of radiation that ended up killing people” says Dr. Mohan Doss, a medical physicist. “The government basically panicked.” Many of those who died were evacuated from intensive care units and other health facilities and did not survive the move. Some deaths were suicides.

If people had stayed put, they would have been OK. Even in the hottest spots, their exposure would have been roughly comparable to receiving a high-resolution whole-body scan each year. But most residents would have received far less radiation. Below a certain threshold, according to Dr. Doss and other scientists, low doses are harmless and possibly even beneficial. The phenomenon of beneficial radiation is called radiation hormesis, which means that weak radiation can have favorable effects. Life evolved in a mildly radioactive environment. What’s more we’re all exposed to a natural “background radiation” from the earth (an amount less than half of what most Fukushima residents received).

Some laboratory experiments and animal studies have shown that low exposures unleash protective antioxidants and stimulate our immune systems, conceivably protecting against cancers. Thirty years ago in Taiwan, authorities discovered that about 200 buildings housing 10,000 people were constructed from steel contaminated with radioactive cobalt. Over the years residents were exposed to double the average for the people of Fukushima. Yet a study in 2006 found fewer cancer cases among these folks compared with the general public. More recently, a study of radon by Johns Hopkins scientist suggested that people living with higher concentrations of the radioactive gas had correspondingly lower rates of lung cancer.

I like the idea of hormesis—the notion that low exposure to toxins and other stressors can be good for you. While scientists don’t know the exact biochemical mechanisms by which it works, the general belief is that low doses of otherwise toxic substances can stimulate our bodies’ natural repair mechanisms. I like the theory because it fits with my overall approach to health: don’t worry about it.

Next week: In defense of fat people

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