Air pollution is everywhere. When it’s elevated, it can challenge even the healthiest individuals. Air pollution has been shown specifically to have adverse effects on the respiratory system. But just how long do the effects last?
A new study suggests that exposure to air pollution more than 30 years ago may still be a factor in a person’s lung disease. This new study followed more than 368,000 people over a 38-year period in England and Wales. Air pollution levels were measured every 10 years. The study found that there were measurably higher risks for chronic bronchitis, emphysema and pneumonia in individuals exposed to air pollution thirty years earlier. The study also found an increased risk of mortality from cardiovascular disease associated with this years ago exposure to air pollution.
This is not the first time that the effects of pollution have been studied for its lasting effects on lung disease. Research finds the effects are even more dramatic in children.
The California Environmental Protection Agency Air Resources Board has done at least at least two studies on the effects of air pollution on children living in high traffic density neighborhoods in the Los Angeles area. A separate study found that there was a higher prevalence of asthma in disadvantaged and high-traffic neighborhoods in Los Angeles County.
In another study, the Board looked retrospectively over an eight-year period at the data collected from 7,000 children during hospital visits and found an association with hospital activity (visits and treatments) and exposure to primary and secondary organic aerosols.
What are the specific elements of air pollution?Ozoneis a form of fortified oxygen (O3 instead of regular oxygen gas which is O2). It can be considered a “good gas” when it occurs in the stratosphere, 20 miles above the earth, where it forms a protective layer. However, when it occurs very close to the earth’s surface after a reaction between nitrous oxides and volatile organic compounds (VOCs), it is highly toxic. There is a condition called oxygen toxicity, which can occur in hospital patients given a high concentration of oxygen, and it’s related to the presence of this O3 (super oxide ion) formation. One of the more dreaded consequences of this condition is lung scarring or ** pulmonary fibrosis**.
Nitrogen oxides are formed whenever fuel, gasoline vapors, and other volatile organic compounds are combusted at high temperatures and fixed with nitrogen in the air. The major sources of nitrogen oxides are emissions from transportation vehicles. Indoor sources are stoves, heaters and cigarette smoking.
Sulfur oxides can be primary gases such as sulfur dioxide, or secondary particulates formed when fossil fuels containing sulfur (coal or oil) are burned during smelting of metals and during other industrial processes. Most of the sulfur dioxide in the United States comes from electric utilities, especially those that burn coal, but it also results from oil refineries and metal processing facilities.
Pollens are natural pollutants from plants, grasses, and trees. Pollens are extremely light, travel long distances with the wind, and remain airborne for days. Individuals with underlying allergies are the most susceptible to their effects.
Particulate Matter (PM) is a class of solid or liquid particles that form aerosols and thus can remain suspended in air. Particles that are less than ten microns in size are able to penetrate the lower airways of the lungs. The measures used to determine air quality, a PM10 for example, indicates the count of PM of a size of ten microns and PM 2.5 for those sized at 2.5 microns.
The Environmental Protection Agency (EPA) considers a PM 10 count of 50 micrograms per cubic meter in outdoor air, averaged over a 24-hour period, to be the standard for safety.
The state of California became known years ago for having some of the worse air pollution in the country, and has made large strides by instituting drastic measures in automobile and industry regulations.
It is evident that living in an industrialized society, we cannot avoid exposure to all the air hazards I’ve just described. Awareness of air quality measures on a given day and implementing efforts to avoid outdoor activities on days with high levels of air pollutants is the best way to limit exposure and health consequences.
Awareness of indoor pollutants and implementing modification of your indoor environment is another important strategy to limit pollution exposure. The U.S. Environmental Protection Agency offers air quality measures nationwide and links to local information as well.
Eli Hendel, M.D. is a board-certified Internist and pulmonary specialist with board certification in Sleep Medicine. He is an Assistant Clinical Professor of Medicine at Keck-University of Southern California School of Medicine, Qualified Medical Examiner for the State of California Department of Industrial Relations, and Director of Intensive Care Services at Glendale Memorial Hospital. His areas of expertise in private practice include asthma, COPD, sleep disorders, obstructive sleep apnea, and occupational lung diseases.