A study out of Italy could have ramifications for the United States and other countries with disinfected tap water. The study found that infants whose mothers drank water with two chemical byproducts were more likely to be born with spina bifida or a cleft palate.
The study was based in the Emilia Romagna region of northern Italy. In addition to using chlorine, which creates a chemical byproduct known as trihalomethanes (THM) that is regulated in both Europe and the United States, the Emilia Romagna region also treats water with two other disinfectants: chlorine dioxide and sodium hypochlorite. These disinfectants create chemical byproducts such as chlorite, chlorate and chloride ions.
Researchers looked at the connection between eight types of birth defects and the mother's exposure to THMs, chlorate, and chlorite in drinking water during her first trimester of pregnancy. In particular, researchers examined: the number of babies born in Emilia Romagna with congenital abnormalities (6,134) compared with those born without abnormalities; the water authority responsible for delivering water to the mother's address during her first trimester; the mother's exposure to chemical byproducts; and the mother's exposure to THMs and chlorine required to be at regulation levels.
The study found that 3.4% of pregnant mothers were likely exposed to levels of chlorite higher than the nationally allowable threshold, resulting in them being three times more likely of giving birth to infants with renal defects, and almost seven times more likely of having a baby with abdominal wall defects. As for chlorate, pregnant mothers exposed to extremely high levels were 9.6 times more likely to have a baby born with a cleft palate, nearly five times more likely to have a baby born with spina bifida, and nearly three times more likely of having a baby with obstructive urinary defects, compared to mothers who were exposed to much lower levels.
Researchers noted that the study samples were quite small, which meant that more studies would need to be conducted in order to verify whether the study's findings were, in fact, accurate. If they are accurate, it could pose a problem for any country considering alternative ways of disinfecting drinking water. At present, THMs have already been linked to birth defects and cancer. It is unknown what other effects chemical byproducts -- which people are exposed to through showering, as well as drinking -- may have on people as a whole.