Wednesday, August 02, 2006

IAQ Update - Allerair Newsletter

Harvard Study Bolsters Link between Pesticides and Parkinson's




By Karen Schrock, Scientific American

People who have been exposed to pesticides are 70 percent more likely to develop Parkinson's disease than those who haven't, according to a new study. The results suggest that any pesticide exposure, whether occupationally related or not, will increase a person's risk of the disease. This means that using pesticides in the home or garden may have similarly harmful effects as working with the chemicals on a farm or as a pest controller.

The research, published in the July issue of Annals of Neurology, provides the strongest evidence to date of the link between pesticide exposure and Parkinson's. The study included over 143,000 men and women who completed extensive lifestyle questionnaires beginning in 1982, and follow-up surveys through 2001. All subjects were symptom-free at the beginning of the project, when they were asked about their occupation and exposure to potentially hazardous materials. Since then, 413 of them have developed confirmed cases of Parkinson's, with a greater incidence of the disease in those who spent time around pesticides. "Low- dose pesticide exposure was associated with a significant increase in risk for Parkinson's disease," says lead author Alberto Ascherio of the Harvard School for Public Health. "I think this is one reason to be careful about using pesticides in general."

Although the causes of Parkinson's are not well understood, it has long been suspected that environmental factors play a large role. Animal studies have shown that chemical compounds commonly used as pesticides can cause a degeneration of dopamine-producing neurons. In Parkinson's, a shortage of dopamine causes the disease's characteristic motor abnormalities, including muscle tremors and muscle rigidity. Previous small-scale human studies had suggested a link between pesticides and Parkinson's, but this new study is the first to establish a clear correlation in a large patient population.

The researchers also looked for links between Parkinson's and other environmental contaminants, including asbestos, coal dust, exhaust, formaldehyde and radioactive material. They found no correlation between the disease and any of the materials besides pesticides, however. Because of the design of the questionnaires, the study was not able to determine how the frequency, duration, or intensity of pesticide exposure affected the incidence of Parkinson's. The next step, according to Ascherio, is to figure out which class of chemicals is actually causing the disease, so that people can reduce their exposure.

It is well known within the air purification industry that purification devices that produce ozone are actually harmful, not helpful. Though it is well known that ozone itself carries negative health effects, a recent study also points to other dangers of ozone. Ozone (O3) "neutralizes" chemicals in the air by attaching a oxygen atom to the chemical. However, this new chemical that is produced may carry its own dangers.

Ozone Interaction May Produce Formaldehyde

United Press International





BERKELEY, Calif., July 17 (UPI) -- Ground-level ozone pollution, aproblem in summer in many U.S. cities, may contribute to a previously unrecognized form of indoor air pollution.

Ozone seeps indoors from outdoor air and it also forms indoors from operation of certain increasingly popular electronic "air purifiers," as well as printers, faxes and other office equipment, according to William Nazaroff.

Nazaroff, Hugo Destaillats and colleagues at the Lawrence Berkeley National Laboratory report that ozone can interact with ingredients in household cleaning products and air fresheners to produce a group of secondary air pollutants. The researchers' tests included a pine-oil cleaner, an orange-based household cleaner and a plug-in air freshener.

Ozone interacted with the products to form secondary air pollutants that included formaldehyde, a known human carcinogen and mucus membrane irritant, according to the study published in the journal Environmental Science & Technology.

The full study can be found here (pdf) - http://pubs.acs.org/cgi-bin/sample.cgi/esthag/2006/40/i14/pdf/es052198z

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