Drivers of maternal accumulation of organohalogen pollutants in Arctic areas (Chukotka, Russia) and 4,4′-DDT effects on the newborns

Background: One of the most worrying consequence of the production and use of persistent organohalogen pollutants (POPs) is the high accumulation in Arctic populations because of long-range transport. Study of the effects in these populations may illustrate human impacts that are difficult to assess in other locations with lower exposure to these compounds and more diverse pollutant influences. Objective: We aimed to identify the main maternal characteristics influencing on the accumulation of these compounds and the effects on the newborns in a highly exposed Arctic population (Chukotka, Russia). Methods: Organochlorine and organobromine compounds were analysed in maternal venous serum (n=250). The study included data on residence, educational level, age, parity and body mass index (BMI) from selfreported questionnaires and measured anthropometric characteristics of newborns. Results: Concentrations of β-hexachlorocyclohexanes, hexachlorobenzene, 4,4′-DDT and polychlorobiphenyls were high when compared with those generally found in adult populations later than year 2000. The polybromodiphenyl ethers were negligible. These POP concentrations were higher than in Alaska and Arctic Norway and similar to those in Canada. The Chukotka mothers living in inland areas showed significant lower concentrations than those living in the coast (p < 0.001) except for 4,4′-DDT. The population from the Chukotsky District, a specific coastal area, showed the highest concentrations. Residence was therefore a main concentration determinant (p < 0.001) followed by maternal age, and in some cases parity and BMI (p < 0.05). 4,4′-DDT showed an association with the anthropometric characteristics of the newborns (p < 0.05). Mothers with higher 4,4′-DDT concentrations had longer gestational ages and gave birth to infants with higher weight and length. Conclusions: The maternal accumulation patterns of POPs were mainly related with residence. Most of these compounds were found in higher concentration in women living at coastal areas except 4,4′-DDE and 4,4′-DDT which were of inland origin. This last pesticide was the pollutant showing positive associations with gestational age and newborn's weight and length. To the best of our knowledge, this is the first study reporting statistically significant associations between maternal 4,4′-DDT exposure and anthropometric characteristics of the newborns