Long-term exposure to traffic-related air pollution may contribute to the development of COPD with possibly enhanced susceptibility in people with diabetes and asthma.

OBJECTIVEdAnimal and cross-sectional epidemiological studies suggest a link between air pollution and diabetes, whereas the limited prospective data show mixed results. We studied the association between long-term exposure to traffic-related air pollution and incidence of diabetes.RESEARCH DESIGN AND METHODSdWe followed 57,053 participants of the Danish Diet, Cancer, and Health cohort in the Danish National Diabetes Register between baseline (1993-1997) and 27 June 2006. We estimated the mean levels of nitrogen dioxide (NO 2 ) at the residential addresses of the cohort participants since 1971 and modeled the association between NO 2 and diabetes incidence with a Cox regression model, separately for two definitions of diabetes: all cases and a more strict definition where unconfirmed cases were excluded.RESULTSdOver a mean follow-up of 9.7 years of 51,818 eligible subjects, there were 4,040 (7.8%) incident diabetes cases in total and 2,877 (5.5%) with confirmed diagnoses. Air pollution was not associated with all diabetes cases (hazard ratio 1.00 [95% CI 0.97-1.04] per interquartile range of 4.9 mg/m 3 mean NO 2 levels since 1971), but a borderline statistically significant association was detected with confirmed cases of diabetes (1.04 [1.00-1.08]). Among confirmed diabetes cases, effects were significantly enhanced in nonsmokers (1.12 [1.05-1.20]) and physically active people (1.10 [1.03-1.16]).CONCLUSIONSdLong-term exposure to traffic-related air pollution may contribute to the development of diabetes, especially in individuals with a healthy lifestyle, nonsmokers, and physically active individuals. 35:92-98, 2012 Diabetes Care

BackgroundVehicle engine exhaust includes ultrafine particles with a large surface area and containing absorbed polycyclic aromatic hydrocarbons, transition metals and other substances. Ultrafine particles and soluble chemicals can be transported from the airways to other organs, such as the liver, kidneys, and brain. Our aim was to investigate whether air pollution from traffic is associated with risk for other cancers than lung cancer.MethodsWe followed up 54,304 participants in the Danish Diet Cancer and Health cohort for 20 selected cancers in the Danish Cancer Registry, from enrolment in 1993-1997 until 2006, and traced their residential addresses from 1971 onwards in the Central Population Registry. We used modeled concentration of nitrogen oxides (NOx) and amount of traffic at the residence as indicators of traffic-related air pollution and used Cox models to estimate incidence rate ratios (IRRs) after adjustment for potential confounders.ResultsNOx at the residence was significantly associated with risks for cervical cancer (IRR, 2.45; 95% confidence interval [CI], 1.01;5.93, per 100 μg/m3 NOx) and brain cancer (IRR, 2.28; 95% CI, 1.25;4.19, per 100 μg/m3 NOx).ConclusionsThis hypothesis-generating study indicates that traffic-related air pollution might increase the risks for cervical and brain cancer, which should be tested in future studies.

Exposure to residential road traffic noise was associated with a higher risk for stroke among people older than 64.5 years of age.