A researcher at the University of Rochester in New York has found that workers exposed to high levels of lead on the job have an increased risk of dying from brain cancer. Epidemiologist Edwin van Wijngaarden looked at data about more than 300,000 people over a nine-year period, comparing the kinds of jobs they had with their causes of death, and he saw a correlation.
"What I found was that people who had any likelihood or any chance of exposure to lead on the job had about a 50 percent increase of death from brain tumors." And, he says, automobile and heavy equipment mechanics, painters and welders -- who were more likely to be exposed to lead for longer periods of time -- had even higher risks of developing brain cancer than workers unexposed to lead.
"We've all at some point been exposed to lead in our lives," Van Wijngaarden points out, adding that the toxic metal is still present in some homes and neighborhoods, despite efforts to eliminate it. "So lead has been a very common exposure over the past half century or so, and if a common toxic exposure has an impact on health, it could affect a large sample of the population," he concludes.
Most research on lead has focused on its effect on children. Van Wijngaarden says not much is known about its impact over a lifetime. "There has been some link with blood pressure and possibly cardiovascular disease. But on the population level, lead has not really been studied much in relation to cancer."
Wijngaarden found only 119 brain tumor deaths. He is continuing his research, looking now at patients who already have brain tumors, to see whether they have higher levels of lead in their bones than other patients.