When you read about health issues caused by air pollution, one automatically thinks about pulmonary problems. But there is now consideration of a new link between a particular kind of air pollution and Parkinson’s disease. Can air pollution cause Parkinson’s Disease?
Nitrogen dioxide (NO2) is produced by internal combustion engines burning gasoline. High levels of NO2 in the air can be caused by motor vehicle traffic outdoors, and from cigarette smoke, and butane and kerosene heaters and stoves indoors.
A retrospective study by Korean scientists found that people living in area with the highest NO2 exposure had a 41% higher risk of newly diagnosed Parkinson’s disease that people who lived in area with the least exposure. Their findings were published in JAMA Neurology.
It is now thought that exposure to environmental pollution, including pesticides, metals, and other fine particulate material is associated with Parkinson’s and other neurological diseases. The pathophysiology of this association is particularly interesting. “Pathological studies have found that the olfactory bulb is commonly filled with misfolded alpha-synuclein and that Lew bodies in the olfactory bulb preceded those in the intracerebral basal ganglia structures.”
In simple terms, these environmental pollutants are breathed in through the nose and cause olfactory abnormalities that then affect brain cells. Among the earliest and most common features of Parkinson’s is a loss of smell, or hyposmia. This seems to support the theory of how Parkinson’s and the olfactory process are related.
The association between air pollutants and Parkinson’s and Alzheimer’s has not yet been firmly established, but is primarily found in retrospective studies such as the one from Korea. There are much larger – and well-known — risks associated with environmental pollutants such as the pesticide paraquat and the industrial solvent trichloroethylene.
But the authors point out that “air pollution, which is often concentrated in densely populated urban areas, may affect hundreds of millions of people, so small increases in risk can have large effects.”
