Cohort study of thyroid disease near the Nevada Test Site: a preliminary report.
The atmospheric testing of nuclear weapons in Nevada beginning in 1951 resulted in exposure of regions surrounding the Nevada Test Site (NTS) to fallout. A cohort of children born between 1947 and 1954 in two counties near the NTS, one in Utah and one in Nevada (UT/NV), were examined in 1965-1968 for thyroid abnormalities that might have been a result of exposure to radioiodine in fallout. The prevalence of thyroid abnormalities in these children (11-18 y) was compared to that in a control group selected from a county in Arizona (AZ) that was presumed to have received little or no fallout from the NTS. Thyroid nodules were found in 76 of the 4,819 children examined (15.8/1000). Of the 76 thyroid nodules, 22 were diagnosed as neoplasms. The rate of thyroid neoplasms among the UT/NV subjects was higher (5.6/1000) than among the AZ subjects (3.3/1000) (RR = 1.7), but because the number of neoplasms was small, the difference was statistically insignificant. In 1985-1986, 3,122 of the original study subjects were reexamined. In this reexamination, thyroid nodules were found in 125 individuals (44.2/1000). Of the 125 thyroid nodules detected during this later study period, 65 were considered to be thyroid neoplasms. Rates of thyroid neoplasms in UT/NV (24.6/1000) are again slightly higher than in AZ (20.2/1000) (RR = 1.2), but the difference is not significant (p = 0.65). Based on the rates of thyroid neoplasms in the two geographic locations, we conclude that living near the NTS in the 1950s has not resulted in a statistically significant increase of thyroid neoplasms in subjects from UT/NV when compared with subjects of the same age and gender living in AZ.
University Medical Center, University of Utah, Salt Lake City 84132.
M L
ML
Rallison
T M
TM
Lotz
M
M
Bishop
W
W
Divine
K
K
Haywood
J L
JL
Lyon
W
W
Stevens
D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D009505:Nevada / Q000453:epidemiology; D009689:Nuclear Warfare; D011847:Radioactive Fallout; D013959:Thyroid Diseases / Q000453:epidemiology* / Q000209:etiology; D014589:Utah / Q000453:epidemiology
D007457:Iodine Radioisotopes; D011847:Radioactive Fallout