Relation of Trihalomethane Concentrations in Public Water Supplies to Stillbirth and Birth Weight in Three Water Regions in England

Abstract

We investigated the association between total trihalomethanes (TTHMs) and risk of stillbirth and low and very low birth weight in three water regions in England, 1992–1998; associations with individual trihalomethanes (THMs) were also examined. Modeled estimates of quarterly TTHM concentrations in water zones, categorized as low (< 30 μg/L), medium (30–59 μg/L), or high (≥60 μg/L), were linked to approximately 1 million routine birth and stillbirth records using maternal residence at time of birth. In one region, where there was a positive socioeconomic deprivation gradient across exposure categories, there was also a positive, significant association of TTHM with risk of stillbirth and low and very low birth weight. Overall summary estimates across the three regions using a random-effects model to allow for between-region heterogeneity in exposure effects showed small excess risks in areas with high TTHM concentrations for stillbirths [odds ratio (OR) = 1.11; 95% confidence interval (CI), 1.00–1.23), low birth weight (OR = 1.09; 95% CI, 0.93–1.27), and very low birth weight (OR = 1.05; 95% CI, 0.82–1.34). Among the individual THMs, chloroform showed a similar pattern of risk as TTHM, but no association was found with concentrations of bromodichloromethane or total brominated THMs. Our findings overall suggest a significant association of stillbirths with maternal residence in areas with high TTHM exposure. Further work is needed looking at cause-specific stillbirths and effects of other disinfection by-products and to help differentiate between alternative (noncausal) explanations and those that may derive from the water supply.

Chemicals in the water environment. Where do the real and future threats lie?

“…Several studies also reported positive associations between THM concentrations and a number of adverse reproductive effects, particularly stillbirth and low weight for gestational age [25,26]. However, as better studies were carried out these were increasingly negative and evidence started to emerge of confounding factors.…”

Presença de trialometanos na água e efeitos adversos na gravidez

“…Quanto maior o tempo de contato da maté-ria orgânica com o cloro, maior a produção de trialometanos 5 . Vários estudos [6][7][8][9][10] têm demonstrado uma associação entre a presença de trialometanos na água de abastecimento, em concentrações que variam entre 80 e 100µg/L, e efeitos na saúde da população. Também tem-se focalizado a relação entre a concentração de trialometanos e efeitos adversos no aparelho reprodutor, bem como no desenvolvimento fetal.…”

Effects of key reaction parameters on the reductive dechlorination of chloroform with Pd/Fe0bimetal in aqueous solution

“…However, formation of chlorinated byproducts such as trihalomethanes (THMs) that are recognized to cause adverse health effects is of great concern. [1,2] Besides the employment of advanced oxidation processes such as ozonation, photocatalytic oxidation, and Fenton reaction for oxidative degradation, the chlorinated byproducts could be alternatively reduced to their nonchlorinated analogues [3] with less toxicity and better biodegradability.…”