Rising Thyroid Cancer Incidence Proximate to a New York City-Area Nuclear Power Plant

Thyroid cancer incidence has risen steadily in the US for several decades. While any cause of this trend has yet to be clearly identified, most analyses have concluded that there are factors other than improved detection accounting for the increase. Since exposure to radioactive iodine is the only acknowledged root cause of thyroid cancer, a review of temporal trends in incidence since the late 1970s near the Indian Point nuclear power plant, just 23 miles from the New York City border, was conducted. Rates in the four counties closest to Indian Point, where virtually the entire population resides within 20 miles of the plant, were compared with national trends in the US. The relative ratio in the local area was 0.778 in the period 1976-1981, or 22.2 percent lower than the national rate. This ratio increased steadily, to 1.579 (57.9 percent greater than the US) by the period 2000-2004, which slightly declined to 1.515 (51.5 percent greater) in the latest period available (2010-2014). Significant increases occurred for both males and females, and in each of the four counties. Annual new cases diagnosed among residents of the four counties increased from 51 to 412 between 1976-1981 and 2010-2014. Because the two large reactors at Indian Point began operations in 1973 and 1976, and exposures to radioiodine isotopes can manifest as cancer from five years to several decades after exposure, iodine emissions from Indian Point emissions should be considered as a potential factor in these trends. More studies near Indian Point and other nuclear installations should be conducted to further explore this potential association.