A controversial new study from the United Kingdom has concluded that pregnant women living near landfills may have a slightly higher risk of bearing children with birth defects or low birth weights.

Funded by the British government, the study finds that four out of five U.K. residents, or 80 percent of the population, live within 1.25 miles of a landfill. According to the study, babies born to women living this close to landfills may experience problems with their central nervous systems and abdominal walls, as well as other anomalies.

Researchers found that the overall risk of birth defects was 1 percent higher in those living within 1.25 miles of landfills, and the risk of low birth weights was 5 percent higher. Those living near hazardous waste sites had a 7 percent higher rate of birth defects.

Despite the seemingly alarming statistics, researchers note that the report does not conclusively link living near landfills with birth defects. The study also did not take other lifestyle factors into effect, such as smoking and diet.

However, according to Dr. Pat Troop, England's deputy chief medical officer, “We cannot say that there is no risk from landfill sites. But given the small number of congenital abnormalities and the uncertainties in the findings, we are not changing our advice to pregnant women.”

Aside from lifestyle issues, the study is limited by other factors. For example, the study did not strictly compare the risk before a landfill site opened with the risk after it opened. In one case, though, researchers found that risks for abdominal wall defects were higher in one area before a landfill opened than they were during its operation and after it closed, which suggests that other factors may be responsible.

Lending some weight to the study is the fact that it is the first to examine all of the landfills in the country — a total of 19,196. In 1998, a study of hazardous waste landfills throughout Europe found that babies born near hazardous waste sites were one-third more likely to suffer serious heart, circulatory and neural defects — but the study examined only 21 sites.

Still, environmental groups are using the most recent study as an opportunity to urge the British government to continue reducing the amount of waste disposed in landfills. “This study adds to our fears that if you are born near a landfill site, you are more likely to be born with a birth defect,” says Mike Childs, campaign director for Friends of the Earth's United Kingdom office. “Although the authors rightly say that we need further research, the government must not use this as an excuse to delay action.”

The study seems to have little relevance to the United States, which has different waste regulations and definitions, according to one industry source who examined the report. However, it appears to be the latest in a series of studies showing a link between living near waste sites and the incidence of birth defects.

For example, an April 1999 study by the California Birth Defects Monitoring Program, funded by the California Department of Health Services, Sacramento, found that women who lived within a quarter-mile of a Superfund site had a greater risk of having babies with serious heart and neural defects.

In 1998, the New York State Department of Health, Albany, studied 38 state landfills that were thought to be leaking methane gas. The study found that women who lived near these sites were four times more likely to contract bladder cancer or leukemia.

The most notorious of all was a 1989 report showing that children living near the Love Canal, the hazardous waste site near Niagara Falls in New York, suffered from low birth weight and smaller size.

Nearly all of these reports contain caveats regarding their statistical reliability, reinforcing the importance of opening and operating landfills safely.