Federal regulators are beginning the daunting task of trying to determine whether living near nuclear reactors and other facilities is linked to a higher risk of cancer more than two decades after a major study found such a link doesn't exist.

The Nuclear Regulatory Commission has asked the National Academy of Sciences to begin studying multiple cancer types in people living near six nuclear reactors and other sites in California, Connecticut, Illinois, Michigan, New Jersey and Tennessee. The academy will also examine cancers in children born near the plants in a case-control study.

The academy is slated to release its findings in 2014. If successful, the $2 million pilot project could be extended to all of the country's 104 operating reactors, NRC spokesman Scott Burnell said.

The NRC is currently relying on a 1990 National Cancer Institute survey that agency officials have pegged as outdated and limited in scope. That report found cancer mortality rates were not elevated in populations living near 62 nuclear facilities.

The NRC decided to update the study because of high public interest, Burnell said.

The study is slated to begin at six sites: the Dresden plant in Morris, Ill.; Millstone Power Station in Waterford, Conn.; Oyster Creek Nuclear Generating Station in Forked River, N.J.; the decommissioned Haddam Neck plant in Haddam Neck, Conn.; the decommissioned Big Rock Point plant in Charlevoix, Mich.; and the San Onofre plant near San Clemente, Calif. NAS will also review cancer rates in people living near the Nuclear Fuel Services plant in Erwin, Tenn., where nuclear fuel for the Navy's fleet of nuclear-powered aircraft carriers and submarines is manufactured.

But the academy faces challenges in collecting the data, and the leading nuclear industry group, the Nuclear Energy Institute, is opposing the pilot study.

NAS acknowledged in March that some state cancer registries have only recently attained quality data and that information about cancer risks might be insufficient to estimate the amount of radioactive material released from nuclear facilities (Greenwire, March 29).

Information on the movement of populations and external factors may also complicate the academy's findings, including exposure to cigarette smoke, access to health care, contact with toxic chemicals and exposure to other sources of radiation such as medical procedures like CT scans, NAS said.

NEI says it's questionable whether the study will generate "technically defensible results" and pointed out that the academy acknowledged the necessary data may be of poor quality or missing. The industry group also noted that routine releases of effluents into the air and water are carefully monitored and controlled at reactors across the nation.

Burnell said the NRC isn't expecting NAS to observe any increased cancer risks for people living near nuclear plants. The NRC receives information from plant operators -- through ongoing monitoring and sampling -- that suggests any radiation dose to the public is so low that being able to detect a difference in cancer rates is unlikely, he said.

"But the questions remain among the public, so we're having the academy do this work to provide independent answers on this basic question," he said.

Rep. Ed Markey (D-Mass.), an outspoken opponent of nuclear power, applauded the NRC's decision to move forward with the study.

"I have long been concerned about whether there are any adverse health impacts associated with living near nuclear reactors," Markey said in a statement. "It is my hope that this pilot study will result in a thorough, accurate accounting of the health risks associated with living near nuclear facilities."