In this study, we measured the relationship between exposure to air pollutants and RA activity. Data on RA patients were extracted from the Kuwait Registry for Rheumatic Diseases KRRD . ...Air pollution was assessed using air pollution components PM 10 , NO 2 , SO 2 , O 3 , and CO . Air pollution data were obtained from Kuwait Environmental Public Authority K EPA from six different air quality monitoring stations during the same period. ...