Mesothelioma and Lung Cancer News - Return to Menu
Job Exposure to Pesticide Linked to Lung Cancer
By Amy Norton
NEW YORK (Reuters Health) - Nov 30, 2004 - Workers exposed to the pesticide chlorpyrifos may have an elevated risk of lung cancer, U.S. government researchers reported Tuesday.
Scientists at the National Cancer Institute found that among the more than 54,000 farmers and insecticide applicators they followed for six years, those with the highest chlorpyrifos exposure had twice the risk of developing lung cancer as did those who did not work with the pesticide.
Those in the highest-exposure group had worked with the chemical an average of 224 days over their lives.
The fact that the study found an "exposure-response" relationship -- meaning lung cancer risk rose in tandem with chlorpyrifos use -- is probably the strongest piece of evidence that the pesticide may promote lung cancer, study co-author Dr. Aaron Blair told Reuters Health.
However, he and his colleagues are urging caution in interpreting the results, since more research is necessary to establish a definite cause-and-effect relationship.
"This is the first study to show this," Blair said. He added that the findings should be viewed along with the "totality of the evidence available," which includes animal research suggesting that chlorpyrifos is not a strong carcinogen.
Blair and his colleagues report the findings in the December 1st issue of the Journal of the National Cancer Institute.
Chlorpyrifos is widely used in U.S. agriculture, and until recently it was found in many home and garden insecticides. Starting in 2000, the pesticide was phased out of products used in homes, schools, parks and certain other public areas after the Environmental Protection Agency (EPA) revised its risk assessment of the chemical.
Chlorpyrifos, sold as Dursban, is one of an older class of pesticides that can harm the central nervous system, and the EPA move was designed to limit children's exposure to the chemical.
However, there has been relatively little evidence that chlorpyrifos may raise cancer risk, though some laboratory research has suggested it's possible.
The new study recorded the incidence of various cancers among 54,383 farmers and full-time pesticide applicators in Iowa and North Carolina, more than 22,000 of whom had worked with chlorpyrifos. All of the mostly male participants are part of the Agricultural Health Study, a project begun in 1993 to follow the health effects of farmers' and pesticide applicators' occupational exposures.
Blair and his colleagues found that while exposed and unexposed workers had a similar risk of developing cancer in general, lung cancer risk was higher among those who had worked with the pesticide. The link held after the researchers weighed other factors, such as age, smoking, family history of cancer, and other on-the-job exposures.
The findings, Blair said, only apply to people who have worked directly with chlorpyrifos. He explained that the main concern with this and other pesticides is not inhalation, but skin exposure, since the skin is believed to be the main route of pesticide absorption into the body.
SOURCE: Journal of the National Cancer Institute, December 1, 2004.
We're so proud
22/02/2005 - A TERMINALLY-ILL shipyard welder killed his sick wife before hanging himself, an inquest heard. In an apparent act of mercy, cancer victim John Lewis, 56, strangled his blind, wheelchair-bound wife Enid, 57, with a luggage strap.
The former Barrow shipyard welder had days to live and was agonising about how Enid, who had multiple sclerosis, would cope. He had been diagnosed with mesothelioma, an asbestos-related cancer.
Yesterdays inquest into Mrs Lewiss death ruled she had been unlawfully killed. After the hearing Mr Lewiss sister, Margaret OConnor, 53, told the Evening Mail: We are very proud of him. It took a great deal of courage to do that.
That was the only way he could be sure she would be safe. He put himself second. His only concern was Enid. Mr Lewiss brother Joe, also from Liverpool, said: It was a mercy killing. It is the only way for some people and it should be made lawful.
The couples bodies were found by an estate agent who was about to show prospective buyers the bungalow in Riggs Close, Grange, last August. John was hanging from the ceiling while Enid was found in her bedroom with a black and yellow luggage strap around her neck.
South Cumbria Coroner Ian Smith said it was unclear whether Mrs Lewis had consented to the killing. He said that might never be known. No suicide note was found, just a letter typed weeks before with detailed instructions on legal matters.
Study: Natural asbestos risks low
By Eric Bailey
Los Angeles Times
SACRAMENTO, Calif. -- A study has found that everyday exposure to naturally occurring asbestos boosts the chances of developing a deadly form of cancer but also cautioned that the risks were relatively low.
The statewide study by the University of California, Davis, researchers is expected to shade the continuing debate over how to tackle the problem in fast-growing communities in the Sierra foothills, where asbestos fibers embedded in the ground are being unearthed by construction crews.
In California, researchers determined that the risk of contracting mesothelioma -- a rare and lethal form of cancer -- was about one in 100,000 people each year, although those chances increased the closer residents lived to a pocket of natural asbestos.
While the overall danger is low, researchers encouraged public officials to work toward reducing risks of exposure, particularly where new housing developments were pushing into terrain dotted with the type of rock that acts as a seedbed of naturally occurring asbestos.
Marc Schenker, chairman of the University of California, Davis, department of public health sciences and lead author of the study, called the threat in such spots a health hazard that should be considered seriously.
The research, funded by the National Cancer Institute, pinpointed victims of mesothelioma across California during the 10 years ending in 1997.
A person living within four miles of an asbestos deposit has about double the odds of contracting mesothelioma as someone about 40 miles away.
Mesothelioma has a latency period of about three decades but then strikes with a vengeance. Patients typically die within a year of diagnosis.