Consequences which mothers' irrasiation has: risks of children's congenital malformations

It is vital to examine radiation-induced effects in children whose parents were exposed to radiation at their workplaces as it allows to work out standards for technogenic irradiation doses permissible for people in their reproductive age. It also helps to predict adverse consequences of parents being exposed to radiation for their children. Our goal was to analyze congenital malformations (CM) in children whose mothers were employed at "Mayak" Production Association (Mayak PA) and had accumulated pre-conception external gamma-radiation doses. Retrospective examination was performed on 1,190 people born in 1949-1969, 238 of them being children of female workers employed at radiation-hazardous production. We achieved maximum comparability of groups made of children population living in Ozersk in terms of age, birth year, and parents' age at a childbirth, via careful sampling. CM frequency was compared with χ² criterion, Fisher's exact criterion. We calculated odds relations (OR) with 95% confidence interval. To detect any latent factors, we applied factor analysis via principal components method with consequent Varimax normalized rotation. Gonads in female workers employed at Mayak PA were exposed to external gamma-radiation doses within 0.09-3523.7 mGy range; average accumulated dose was equal to 373.6 ± 34.2 mGy. Each tenth child in a group of children born by irradiated mothers was born by a mother who had an accumulated pre-conception external gamma-radiation dose on her gonads which was higher than 1 Gy. CM comparative analysis revealed that there were no statistically significant differences between groups in terms of CM frequency in general and as per various nosologic forms. OR in general was equal to 0.86 (0.46-1.59); 0.88 (0.35-2.2) among boys; 0,84 (0.36-1.94) among girls. We also detected difference in CM structure: CM of the nervous system, respiratory organs (23 % each), and the musculoskeletal system CM (15.3 % among all the malformations) prevailed among all the CM in children born by irradiated mothers; CM of the musculoskeletal system (23.3 %) and the nervous system (21.7 %) were most widely spread among children born by intact parents. We also noted there were gender discrepancies in the CM structure in the compared groups. We didn't register any chromosome pathologies in both groups. CM were diagnosed in those children born by those irradiated mothers whose gonads were exposed to accumulated pre-conception external gamma-radiation doses within 1.9-1635.5 mGy, with average dose being equal to 307.5 mGy. Factor analysis performed on children born by female workers employed at atomic production revealed four factors which characterized pre-concepption mothers' irradiation (21.5 % dispersion), antenatal children's period (17.1 % dispersion), obstetrician-gynecological case history (12.9 % dispersion), and mothers' bad habits, namely alcohol intake and smoking (11 %) dispersion). Given all the detected peculiarities, it is highly advisory to continue research on larger children's groups and longer observations periods.