A SHORT LATENCY BETWEEN RADIATION EXPOSURE FROM NUCLEAR PLANTS AND CANCER IN YOUNG CHILDREN

http://www.radiation.org/spotlight/2006MarChildCancerIJHS.html

International Journal of Health Services
March, 2006

A SHORT LATENCY BETWEEN RADIATION EXPOSURE FROM NUCLEAR PLANTS AND CANCER IN YOUNG CHILDREN
Joseph J. Mangano, MPH, MBA

ABSTRACT
Previous reports document a short latency of cancer onset in young children exposed to low doses of radioactivity. The Standard Mortality Ratio for cancer in children dying before age ten rose in the period 6-10 years after the Three Mile Island and Chernobyl accidents in populations most exposed to fallout. SMRs near most nuclear power plants were elevated 6-10 years after startup, particularly for leukemia. Cancer incidence in children under age ten living near New York and New Jersey nuclear plants increased 4-5 years after increases in average Strontium-90 in baby teeth, and declined 4-5 years after Sr-90 averages dropped. The assumption that Sr-90 and childhood cancer are correlated is best supported for a supralinear dose-response, meaning the greatest per-dose risks are at the lowest doses. Findings document that the very young are especially susceptible to adverse effects of radiation exposure, even at relatively low doses.

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The developing fetus and infant has demonstrated a predisposition to cancer from various types of low-dose radiation exposure within a decade. Pelvic X-rays to pregnant women in the 1950s initially was linked to a near-doubling of the risk of cancer death before age ten. (17-18) Subsequent reports on larger populations confirmed this excess, both for leukemia and other childhood cancers. (19-21)

Elevated levels of radiosensitive cancers in the young shortly after exposure to atmospheric nuclear weapons test fallout have also been documented. Peaks in acute myeloid leukemia deaths in U.S. children age 5-9 occurred in 1962 and 1968, about five years after the peak testing periods of the late 1950s and early 1960s. (22) From 1948-1952 to 1958-1862, the number of Utah residents under age 30 who had their cancerous thyroid gland removed surgically rose from 6 to 30, much faster than the national increase. (23) In five Nordic countries, leukemia incidence in children under age five peaked during the highest periods of fallout from bomb tests. (24)

More recently, an elevation in leukemia diagnosed in the first year of life was seen in children born in 1986 and 1987, just after the accident at Chernobyl, representing a latency period of less than two years between in-utero exposure and diagnosis. These elevations were documented in multiple nations, including Belarus (25), Greece (26), Scotland (27), the U.S. (28), Wales (29), and West Germany (30), plus a grouping of European countries. (31) A latency beginning just four years between the accident at Chernobyl and elevated thyroid cancer rates in children has been reported in Belarus and the Ukraine. (32-34) Rising thyroid cancer incidence in children has also been reported within ten years of the accident in the moderately exposed areas of Belgium (35), East Hungary (36), and northern England (37). While some reports have found no excess in non-thyroid cancers in children irradiated by Chernobyl fallout, elevated rates within ten years of exposure have been documented in the Ukraine (38) and Turkey. (39)

Other reports have found unexpectedly high rates of childhood cancer, often leukemia and typically diagnosed before age ten, near nuclear installations. Early childhood cancer near nuclear plants likely represents effects of exposures in utero and in infancy. In the United Kingdom alone, at least eleven such reports representing different nuclear plants exist. (40-50) Similar results were observed in Canada (51), France (52), Germany (53), and the former Soviet Union. (54) Reports on this topic from the U.S. have been limited to several examining populations near a single facility at least two decades ago. (55-59) Data from a 1990 National Cancer Institute report show that cancer incidence age 0-9 near each of four U.S. reactors exceed the state rate. (60) A recent analysis shows that cancer incidence age 0-9 within 30 miles of each of 14 U.S. plants exceeds the national average for 1988-1997, based on 3669 cases. (61)

The many reports documenting a 5-10 year lag between radiation exposure and childhood cancer onset, plus elevated childhood cancer near nuclear power plants, illustrate the heightened sensitivity of the fetus and infant to toxins. This report will further examine this susceptibility by analyzing temporal trends in childhood cancer in populations exposed to low-dose nuclear power plant emissions 5-10 years after initial exposure.

http://www.radiation.org/spotlight/2006MarChildCancerIJHS.html