Radioactive milk harmless, but will consumers buy it?

Radioactive milk, detected in two states, contains tiny amounts of radioactive iodine that probably originated in Japan but pose no health threat. So far, milk sales seem steady.

Milk waiting to be tested sit on shelves in a cooler at the Environmental Protection Agency’s National Air and Radiation Environmental Laboratory in Montgomery, Ala., March 24, 2011. The laboratory has added a few extra contract workers because of the threat from Japan, officials say, including radioactive milk.

Dave Martin / AP

April 1, 2011

The Environmental Protection Agency (EPA) and the state of California discovered trace amounts of radiation in milk on the West Coast this week, but not nearly enough to cause concern, the agency says – and not enough to impact consumption, say representatives from the milk industry. The level of Iodine-131 that the EPA detected is 5,000 times below the level at which the Food and Drug Administration would intervene.

So far, there has been no effect on the milk business in California, says the executive director of the Dairy Institute of California, a trade association that represents dairies in the state and elsewhere.

“It's hard to say how people will react, but we are hopeful that they will look to the facts that we believe are available to them,” says Rachel Kaldor of the Dairy Institute.

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A spokesman for Dean Foods, the largest dairy processor and distributor in the country that includes brands like Mayfield, Garelick, and California's Alta Dena, says it's too early to tell if there has been any financial impact to the company since the radiation was detected. But the company has seen an increased volume of calls from concerned consumers. Yesterday, about 100 people called to ask about the radiation.

“It's not an alarming volume of calls," says the spokesman Jamaison Schuler. "As a company we have 40 brands across the country, you’re looking at two, two and a half calls per region.”

Iodine-131, or I-131, was found in milk samples from Spokane, Wash., on March 25, and San Luis Obispo County, Calif., on March 28. While milk can normally contain radiation, the particular I-131 is not usually present. So, its presence in the milk has been linked to the release of I-131 from Fukushima Daichii plant in Japan. The EPA found 0.8 picocuries per liter in the Spokane samples. The California Department of Public Health has not yet released the radiation level it detected, but a spokesman said it was comparable to the amount found in the Spokane samples. That amount of radiation is far, far less than the average person gets from natural radiation from the ground and sky, according to one radiological expert.

“It would have been surprising if very low levels of I-131 had not shown up in milk there,” David Brenner, director of the Center for Radiological Research at Columbia University, writes in an e-mail, “But that's a testament to sensitive measurement technology, and not a public health issue.”

For comparison, the human body has 100,000 picocuries of naturally occurring, radioactive potassium, and milk usually contains about 2,000 picocuries per liter of that isotope. The curie, named after Marie and Pierre Curie, is a unit used to measure the rate of decay of radioactive substances. The isotope has a half-life of about eight days, so the level found in the milk will decline rapidly, and should be basically nonexistent within 64 to 80 days.

“From what we think we know about Japan's nuclear accident, we’re pretty confident that that was expelled in the early days,”says Mike Sicilia, a spokesman for the California Department of Public Health.

It's still early to tell if consumers will cut back on milk consumption, but Ms. Kaldor says that if the milk industry were to be affected, it wouldn't happen until the I-131 had disappeared.

"By that time the situation will be resolved, or people will understand [the low risk]," she says.

Normally, the EPA tests milk for radiation every three months at about 30 stations around the country. But, in light of Japan's nuclear crisis, the EPA bumped up the testing dates by a week.The I-131 was probably present in the milk because cattle ingested grass or water that had been contaminated by I-131 that leaked from the nuclear plant.

“We obviously have a challenge of environmental exposure,” says Stephen Apatow, director of research and development at Pathobiologics International, a branch of the Humanitarian Resource Institute in Milford, Conn.

But Mr. Apatow stresses that it’s important to understand how minuscule the radiation levels actually are.

“It’s very easy to create a massive scare,” he says. “Yes, iodine-131 having come from the plant, even in very small amounts, is kind of an alarming thing.”

If ingested or breathed in in large amounts, the isotope would be absorbed by the thyroid gland. Researchers say it would potentially increase the risk of cancer or other thyroid problems. In fact, I-31 is commonly used to diagnose and treat thyroid cancer, but at considerably higher doses than was seen in the milk.

When the FDA sets safety levels for radiation, it takes into consideration that people could be ingesting the harmful element on a regular basis for an extended period of time. So, even if people are continuously drinking milk with such trace amounts of radiation as were found in Washington and California, they should not be worried.