A new Canadian study suggests a link between air pollution and autoimmune diseases like rheumatoid arthritis and lupus. Researchers analyzed demographic data from Alberta and Quebec over roughly a 20 year period to search for correlations between ambient pollution levels in certain areas of each province and medical records of people in those areas suffering from autoimmune rheumatic diseases. The results confirmed a correlation.
“Our data suggest that fine particulate (PM2.5) exposure may be associated with an increased risk of systemic autoimmune diseases (SARDs),” the study’s authors write.
Fine particulate pollution is air pollution containing microscopic materials of a size 2.5 microns or smaller – 1/30th the width of a human hair. Different chemicals make up these pollutants such as nitrates and sulfates, carbon, soil and dust particles. Their small size allows them to be breathed deep into the lungs and result in a host of health problems, including asthma, cardiovascular disease and lung cancer.
Sources of outdoor fine particulate matter include motor vehicles and industrial plants while indoor sources include cigarette smoke, cooking fumes and cleaning products. According to the Ontario Ministry of the Environment and Climate Change, adverse health effects can result from fine particulate exposure over a period of years but also from short term exposure – in some circumstances as brief as one day.
Whereas the effects of fine particulate pollution on respiratory health are well documented, the connection between pollution and autoimmune disease is only now being uncovered.
But whereas the effects of fine particulate pollution on respiratory health are well documented, the connection between pollution and autoimmune disease is only now being uncovered.
Scientists theorize that for those who have contracted autoimmune rheumatic diseases, exposure to pollutants could have played a role in triggering the production of autoantibodies in the lungs and the transformation of the amino arginine into the citrulline, known precursors to autoimmune disease.
The World Health Organization says worldwide, fine particulate pollution causes 16% of lung cancer death, 11% of chronic obstructive pulmonary disease and more than 20% of ischaemic heart disease and stroke.
In Canada, millions are afflicted with autoimmune diseases, with rheumatoid arthritis alone affecting 1% of Canadian adults (at least twice as many women as men are affected).
The research on the link between autoimmune disease and fine particulate pollution is in its infancy stage, however, as evidenced by a recent review published in Rheumatologist, the journal of the American College of Rheumatologists, which asked the question, is there an association between air pollution and rheumatic disease? Their answer? “At this time, there is no definitive association determined for any air pollutant in any rheumatic disease. More data are needed to elucidate the progression from pollution-related immune stimulation, the formation of antibodies and the ultimate progression to clinically apparent disease.”
The Government of Canada recommends that to limit indoor exposure to fine particulate pollution, residents should ensure adequate ventilation and use in-duct air filters and stove top fans. And, of course, don’t smoke.
The lead author of the new study is Dr. Sasha Bernatsky of the Department of Epidemiology, Biostatistics and Occupation Health at McGill University.
The study was published in the December 2015 edition of the journal Environmental Research.