Essay: Is This the Poster Food for a Radiation Menace?

I didn’t have much use for them until I started writing about radiation from the damaged nuclear reactors at the Fukushima Daiichi power plant in Japan. Recently, one of my interviews took a turn for the weird. I asked a scientist about possible health effects from radioactive materials leaking out of the plant, and he started talking about bananas.

“Why, we ingest radioactive material every day,” he said in a tone of wonderment. “Bananas are a most potent source.”

They contain a naturally occurring form of radioactive potassium, more than other fruit, he explained.

“It stays in our body, in our muscles,” he said. “Every second, our bodies — yours and mine — are irradiating.”

Brazil nuts are even hotter than bananas, he added, sounding almost gleeful. “The radium content is off the wall!”

I tried to steer the interview back to nuclear reactors, and for a few minutes it seemed to work. He said unnecessary exposures to radiation should be avoided.

But then he said: “I love bananas. I will not give them up.”

A few days later, I tried another expert, halfway across the country from the first. I asked about radioactive iodine and cesium being found in some Japanese milk and produce.

He said there wasn’t much risk, but it would probably still be better not to eat the food. Then he said, “I just had a banana for lunch.”

Uh oh, I thought, here comes the banana speech again. Is there a script circulating out there in radiation land, “How to Calm the Public With Bananas”?

“Bananas are radioactive,” he went on soothingly. “Everything is radioactive, including the food we eat and, for many people in this country, the water we drink. There is a point at which we say there’s no more than Mother Nature out there.”

Is there a point at which we say the urge to reassure people might get in the way of straight answers? A point at which, for instance, a reporter might think that if one more person brings up bananas, she herself will melt down, or, with all due respect, giggle.

I know the experts were just trying to put the invisible menace of radiation into perspective. But it did feel like a Wizard-of-Oz effort to distract the audience from the real questions: Pay no attention to those fuel rods behind the curtain!

When I told Peter Sandman about the banana speech, he laughed. Dr. Sandman is a risk communication expert based in Princeton, N.J., who has spent much of his long career advising scientists to avoid doing things like answering in bananas when the question is milk.

“The right comparison is the food they’re talking about,” Dr. Sandman said. “You can say: ‘The average amount is X. Now we’re seeing Y.’?”

“It’s very bad risk communication to communicate in ways that make people feel as if you think they’re stupid,” he said.

He said he had worked with nuclear scientists who were irritated by the public’s ignorance about radiation, but were also proud to be recognized as experts. Pride plus irritation, he said, can be a recipe for pronouncements that come off as pompous and condescending. Mix in an agenda — whether it’s the urge to reassure people, or to stir them up — and the message can really backfire.

“People smell it,” Dr. Sandman said. “And they don’t trust you.”

That’s where the Geiger counters come in handy. Just how radioactive are bananas?

My husband, who teaches high school chemistry, took a banana to school and tested it with one of the Geiger counters he keeps in his classroom. He put the probe near the banana, then against the skin, then poked into the fruit — two five-minute runs at each spot. He did multiple runs to test the background radiation in the classroom. For good measure, he even tested an apple, an orange and a granola bar. The banana was not so hot. Not hot at all, in fact, no more counts per minute than the other stuff, or the background. He ate the banana.

I’m not saying the experts were wrong. But my husband staunchly defends the sensitivity of his Geiger counter. Maybe it was an odd banana. It doesn’t matter now.