Lifetime exposure to lead from paint in older houses, drinking water pipes and other sources appears to increase men’s risk of cataract development, researchers reported Tuesday.
“This research suggests that reduction of lead exposure throughout a man’s lifetime should help reduce his chances of developing cataracts and of requiring cataract surgery,” said Debra Schaumberg of Brigham and Women’s Hospital in Boston, lead author of the study.
“By preventing or delaying the onset of this condition, many instances of blindness worldwide could be prevented,” she added.
Her study, published in this week’s Journal of the American Medical Association, looked at data from 795 U.S. men age 60 and older for whom bone lead levels were measured between 1991 and 1999. The report did not speculate about whether the findings would also apply to women.
Leading cause of blindness
In the United States about 20 percent of those in their 60s develop cataracts. The problem accounts for more than 40 percent of all cases of blindness worldwide, the report said.
Schaumberg and colleagues found that those with the highest levels of lead exposure had more than two-and-a-half times the risk of developing cataracts compared to those with the lowest levels.
“Lead exposure continues to pose a significant public health problem,” she said.
“While lead exposure has been reduced over the past several decades, for example through the elimination of leaded gasoline, it has not been eliminated, and older Americans still have a significant amount of lead accumulated in their bodies,” she added.
“Because prevention of age-related cataracts is an important worldwide public health goal, this study adds to the evidence that continued reduction of lead exposure should be a priority, she said.
In the United States where more than 80 percent of homes built before 1980 are believed contaminated by lead-based paint, leaded water pipes or both. Accumulated lead in the body has previously been linked to high blood pressure and mental decline.
Lead stored on bones migrates from the skeleton and circulates in blood plasma at low levels, the study said. While the way it may impact cataract formation is not clear, some previous research has suggested it could affect protein formation in the eye lens, the report added.