Link Between Air Pollution and Rheumatoid Arthritis

Air pollution is associated with increased risk of developing rheumatoid arthritis, reveals research.Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.
Environmental factors have been connected with the development of RA, and exposure through a person''s airways is of particular interest to researchers. Researchers from Brigham and Women''s Hospital in the United States and the Karolinska Institute in Sweden recently examined whether long-term exposure to air pollution is associated with an increased risk of RA. They studied 1,330 cases of RA (as well as an additional 2,235 people without the disease) from the Swedish Epidemiological Investigation of Rheumatoid Arthritis, and 91,203 women from the US Nurses'' Health Study (among whom 762 developed RA over 30 years of follow up).
The researchers predicted exposures to several common air pollutants, classified as either gaseous (air pollution in gas form, such as carbon monoxide, sulfur dioxide and nitrogen dioxide) or particulate (air pollution that contains tiny particles, such as soot or dust), at homes of all participants based upon residential addresses. Then, they examined the association between increases in these different components of air pollution with the increased risk of developing RA. While looking at the risk associations between air pollution and RA, the researchers took into account other variables that might affect RA risk, such as age, gender, socioeconomic status, education, race, smoking ,reproductive factors, hormone use, physical activity and body mass index.