Low Birth Weight and Exposure to Disinfection By-Products in Pregnant Women in Crete (Rhea Study)

Abstract

ISEE-0517 Background and Objective: Exposure to disinfection by-products (DBPs) during pregnancy has been associated with adverse birth outcomes. We evaluated exposure to DBPs through ingestion, inhalation and dermal absorption among women, in relation to birth weight and other reproductive outcomes. Methods: The mother-child birth cohort in Crete (“Rhea” study) enrolled 1500 pregnant women at the third month of pregnancy (2007–2008) who were residents in the prefecture of Heraklion. Exposures were assessed through 2 general and 2 Food Frequency questionnaires during pregnancy, requesting extensive information on personal water related habits. Tap water samples were collected in the homes of the representative mothers on the basis of detailed water distribution patterns, and were analysed for major DBPs including trihalomethanes (THMs). Logistic and linear regression models were applied. Results: Pregnant women reported a high consumption of bottled water at home (76%), and work (96%). About a third of the women reported water consumption of more than 1.5 L/day. More than half the women (59%) washed dishes by hand whereas only 12% used a dishwasher, nearly all women (94%) took showers rather than baths (1%), and only 2% attended a swimming pool. THM levels were low (<20 micrograms/L) with a relatively high proportion of brominated compounds. After adjusting for educational status, smoking during pregnancy and ethnicity, birth weight was found to be lower among women drinking tap water (beta coefficient = −132 gr, 95%CI −251 to −14) and those drinking bottled water (beta = −96 gr, −202 to 11) as compared to women drinking water from springs. No statistically significant results were found for other reproductive outcomes. An analysis incorporating home specific modelled total THM and specific THM values is ongoing and is taking into account all routes of exposure. Conclusion: These results provide some evidence of differences in birth weight in relation to source of drinking water.