Cancer incidence among residents of the Three Mile Island accident area: 1982–1995 $ Yueh-Ying Han a , Ada O. Youk b , Howell Sasser c , Evelyn O. Talbott d,n a Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA b Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA c Department of Epidemiology and Community Health, School of Health Sciences and Practice, New York Medical College, Valhalla, NY, USA d Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA article info Article history: Received 17 June 2010 Received in revised form 5 May 2011 Accepted 4 August 2011 Keywords: Three Mile Island Neoplasm Incidence Leukemia Low-dose radiation abstract Background: The Pennsylvania Department of Health established a registry of the Three Mile Island (TMI) nuclear power plant accident in 1979. Over 93% of the population present on the day of the accident within a 5-mile radius was enrolled and interviewed. We used the registry to investigate the potential cancer risk from low-dose radiation exposure among the TMI population. Methods: Cancer incidence data among the TMI cohort were available from 1982 to 1995. Because more than 97% of the population were white and few cancer cases were reported for those younger than 18 years of age, we included whites of age 18 years and older (10,446 men and 11,048 women) for further analyses. Cox regression models were used to estimate the relative risk (RR) per 0.1 m Sv and 95% confident interval (CI) of cancer by radiation-related exposures. The cancers of interest were all malignant neoplasms, cancer of bronchus, trachea, and lung, cancer of lymphatic and hematopoietic tissues, leukemia, and female breast. Results: Among men and women, there was no evidence of an increased risk for all malignant neoplasms among the TMI cohort exposed to higher maximum and likely g radiation (RR ¼1.00, 95% CI ¼0.97, 1.01 and RR ¼0.99, 95% CI ¼0.94, 1.03, respectively) after adjusting for age, gender, education, smoking, and background radiation. Elevation in risk was noted for cancer of the bronchus, trachea, and lung in relation to higher background radiation exposure (RR ¼1.45, 95% CI ¼1.02–2.05 at 8.0–8.8 mR/h compared to 5.2–7.2 mR/h). An increased risk of leukemia was found among men exposed to higher maximum and likely g radiation related to TMI exposure during the ten days following the accident (RR ¼1.15, 95% CI ¼1.04, 1.29 and RR ¼1.36, 95% CI ¼1.08, 1.71, respectively). This relationship was not found in women. Conclusion: Increased cancer risks from low-level radiation exposure within the TMI cohort were small and mostly statistically non-significant. However, additional follow-up on this population is warranted, especially to explore the increased risk of leukemia found in men. & 2011 Elsevier Inc. All rights reserved. 1. Introduction The Three Mile Island (TMI) accident was a partial core melt- down of the Three Mile Island nuclear generating station on March 28, 1979 in Dauphin County, Pennsylvania. The nuclear power plant released about 370 P Bq of noble gases, mainly 133 Xe and 550 G Bq of 131 I were released into the atmosphere (UNSCEAR, 2011). Based on residential location and the amount of time spent within a 5-mile radius area during the 10 days after the accident, Gur et al. (1983) estimated that the average max- imum and likely whole-body g-doses for individuals in this area were 0.25 m Sv and 0.09 m Sv, respectively. Although estimated radiation doses from the incident were low, the Pennsylvania Department of Health created the TMI population registry, which includes more than 35,000 residents living near the TMI facility within two months after the accident in order to monitor the possible health effects from low-level short-term exposure to TMI radiation emissions. A 13-year (Talbott et al., 2000) and a 20-year (Talbott et al., 2003) mortality assessment of the TMI cohort have been reported. Based on the Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/envres Environmental Research 0013-9351/$ - see front matter & 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2011.08.005 Abbreviations: CI, confidence interval; CLL, chronic lymphocytic leukemia; OR, odds ratio; RR, relative risk; TMI, Three Mile Island; UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiation $ Funding: This work was supported by a grant from the Three Mile Island Public Health Fund. No competing interests are declared. n Corresponding author at: Department of Epidemiology, A526 Crabtree Hall, University of Pittsburgh, Pittsburgh, PA 15261. Fax: þ412 624 7397. E-mail addresses: hany2@upmc.edu (Y.-Y. Han), ayouk@pitt.edu (A.O. Youk), howell_sasser@nymc.edu (H. Sasser), eot1@pitt.edu (E.O. Talbott). Environmental Research 111 (2011) 1230–1235