It's long been known that exposure to lead, even at low levels,
might increase the risk of numerous age-related diseases. Now, to
add one more to the list, a study in the Journal of the American
Medical Association (JAMA) has found that long-term lead exposure
increases the risk of cataracts, cloudy areas in the lens of the
eye that cause vision problems and even blindness.
The study, which included close to 800 men in their late 60s and
spanned nine years, was prompted by the fact that lead causes oxidative
damage in body tissues, and cataracts are known to be related to
such oxidative damage.
It was found that men with the most lead in their bones were 2.7
times more likely to have cataracts than those with the least lead.
Bone lead levels, which are more stable over time, were used in
order to determine the effects of long-term exposure, as lead levels
in the blood can vary over the short term. No link was found between
cataracts and lead levels in the blood, which suggests the incidence
of cataracts was associated with exposure to lead over several years
or more.
Researchers said being exposed to lead over time at levels commonly
experienced by U.S. adults appears to be an important risk factor
for cataracts. They suggested that reducing lead exposure could
help to decrease the "global burden of cataract," but
added that additional studies are needed to confirm the finding.
They also pointed out the importance of
protecting yourself from lead exposure in your environment by taking
the following measures:
- Don't use lead-based paint
- Make sure there's no lead in your drinking water
- Don't smoke (there's lead in cigarette smoke)
- Minimize work-related lead exposure
Journal
of the American Medical Association, December 8, 2004;292:2750-2754