SAN DIEGO, May 04 (Reuters Health) - Workers exposed to lead have an
increased risk of developing Alzheimer's disease in later years, according to
research presented here at the American Academy of Neurology's 52nd annual
meeting.
"People who have worked in jobs with high levels of lead exposure are up to
three to four times more likely to develop Alzheimer's disease," said Dr. Amir
Halim Soas, director of the Alzheimer's Project at Case Western University
Medical School's department of neurology.
In the study, Dr. Elisabeth Koss and colleagues at Case Western compared the
work histories of 185 Alzheimer's disease patients with 303 people without the
memory-robbing disorder. The investigators found that those with the highest
on-the-job lead exposure had up to four times the risk of Alzheimer's disease as
those with the lowest exposure levels after taking into account education and
other factors that can influence the disease. Overall, 14% of those with
Alzheimer's had exposure to lead at work compared with 6% of people without the
disease.
The researchers found no association between Alzheimer's disease and
exposure to other potential toxins, such as aluminum, copper, iron, mercury,
zinc and solvents.
Workers can be exposed to lead if they are smelting or casting lead,
removing old lead-based paints, or involved in the manufacture of products such
as lead-acid batteries, lead-glazed pottery, ammunition, lead pipe, cable
shielding, electronic components or paint and ink. People who work with stained
glass can also be exposed to high levels of lead.
Lead can be absorbed through the skin or inhaled as a dust, the most toxic
route of exposure. According to Soas, the Case Western research is the first to
confirm a definite association between occupational exposure and risk of
Alzheimer's.
Laws passed in the 1970s resulted in the removal of lead from gasoline and
paint. However, lead can still be found in the paint in older homes, as well as
in contaminated soil or drinking water, Koss said.
