THMs linked to stillbirths
8/15/2000
HALIFAX, NOVA SCOTIA — Researchers have found a link between
high levels of chlorine byproducts in drinking water and stillbirths in
this Canadian province.
Perinatal data on about 50,000 births was analyzed and correlated
with individual exposure to trihalomethanes (THMs) in public water
supplies, based on the mothers' residences at the time of delivery.
Total THMs and specific THMs both were associated with increased
risk of stillbirth, reported researchers at the IWK Grace Health Centre,
Dalhousie University and Queen's University in Kingston, Canada.
"These findings suggest the need to consider specific chlorination
byproducts in relation to stillbirth risk," wrote the authors, who
published their findings this month in Environmental Health
Perspectives.
The strongest association was found between stillbirths and
bromodichloromethane exposure. Stillbirth risk doubled for mothers
exposed to 20 parts per billion (ppb) of the chemical compared with
those exposed to less than 5 ppb. THM levels were most strongly
associated with deaths caused by asphyxia.
The US Environmental Protection Agency's drinking water limit for
total trihalomethanes is 10 ppb.