May 11, 2001 -- Before you turn on the tap or twist open that fancy bottled water, there are a few things you should know. Even well regulated and tested drinking water can harbor potentially dangerous contaminants, say members of the CDC's elite force of Disease Detectives.
The CDC researchers presented findings from two investigations of drinking water safety at the 50th Annual Epidemic Intelligence Service Conference held this week in Atlanta.
In the first study, Melinda J. Wilkins, DVM, MPH, and colleagues examined infants whose mothers had consumed water containing low levels of arsenic during pregnancy.
"It's well established that very high levels of arsenic are associated with cancer. But very few reproductive studies done have looked at arsenic at low levels. We needed to make sure," says Wilkins, a CDC officer with the Michigan Department of Community Health.
The team analyzed birth records from nearly 320,000 babies born between 1989 and 1998 in nine Michigan counties, looking specifically for low birth weight, preterm birth, and small size for gestational age.
Wilkins says that they chose the area because the water there has some of the highest arsenic levels in the country.
"This is a naturally occurring situation," she tells WebMD. "The arsenic leaches out of the sandstone in the earth." It is not caused by dumping, or any other foreign source. Those relatively high levels still fall well within the EPA's current safety limit of 50 parts per billion.
The team found no evidence that the higher-than-usual arsenic levels in the drinking water had any ill effects whatsoever on the babies. For each of the three variables, "the percentages were close to Michigan as a whole, and not far from national averages," says Wilkins.
"At this point, mothers-to-be don't need to be overly concerned about arsenic," says Wilkins. "Traditional risk factors like smoking and drinking rank much much higher on the list of things to be concerned about when they're pregnant," says Wilkins.
Still, she says, it can't hurt to be cautious, especially when your baby's health is at stake.