Exposure to long-term air pollution and road traffic noise in relation to cholesterol: A cross-sectional study

•Traffic noise and air pollution are both associated with cardiovascular disease.•A potential mechanism includes raised levels of blood lipids.•Air pollution was associated with total cholesterol in a study of 36,039 elderly.•Noise was weakly associated with cholesterol before adjustment for air pollution.•It was difficult to separate effects of air pollution and noise in relation to cholesterol.