Prevalence of Birth Defects in the Vicinity of Hongyanhe Nuclear Power Plant Before Its Normal Operation, from 1996 to 2009

The study was to determine the prevalence, types and epidemiologic patterns of birth defects in the vicinity of Hongyanhe nuclear power plant from 1996 to 2009. Hongyanhe nuclear power plant is the first nuclear power plant in northeast China and the first one receiving central government approval to build four units at the same time. We used the database of the Liaoning Birth Defects Monitoring Network to investigate birth outcomes for infants with defects from 1996 to 2009, in Wafangdian. The infant must have been born in there with a birth diagnosed within 7 days after delivery, and the mothers living in Wafangdian for more than one year were enrolled. During 1996 to 2009, a total of 783 birth defects were identified among 95,632 births, which yielded a prevalence of 81.88 per 10,000 births. The highest prevalences of birth defects was observed in 2007 (128.98 per 10,000 births), and the lowest one was in 1996 (42.24 per 10,000 births). There was an upward trend detected in the time span. The major types of birth defects in our study were: congenital heart disease, hydrocephalus, cleft lip and cleft palate, polydactyly, spina bifida and cleft lip. All of the prevalences were lower than the national prevalence and other studies. The major types of birth defects in our study are similar with the types of national. The prevalences of NTDs and trisomy 21 thought to be caused by ionizing radiation are lower than other studies of China. To our knowledge, few studies about prevalence of birth defects have the large intervals of time, from 1996 to 2009 in northeast China.