Raaschou-Nielsen, O; Beelen, R; Wang, M; Hoek, G; Andersen, ZJ; Hoffmann, B; Stafoggia, M; Samoli, E; Weinmayr, G; Dimakopoulou, K; Nieuwenhuijsen, M; Xun, WW; Fischer, P; Eriksen, KT; Sørensen, M; Tjønneland, A; Ricceri, F; de Hoogh, K; Key, T; Eeftens, M; Peeters, PH; Bueno-de-Mesquita, HB; Meliefste, K; Oftedal, B; Schwarze, PE; Nafstad, P; Galassi, C; Migliore, E; Ranzi, A; Cesaroni, G; Badaloni, C; Forastiere, F; Penell, J; De Faire, U; Korek, M; Pedersen, N; Östenson, CG; Pershagen, G; Fratiglioni, L; Concin, H; Nagel, G; Jaensch, A; Ineichen, A; Naccarati, A; Katsoulis, M; Trichpoulou, A; Keuken, M; Jedynska, A; Kooter, IM; Kukkonen, J; Brunekreef, B; Sokhi, RS; Katsouyanni, K; Vineis, P
BACKGROUND: Particulate matter (PM) air pollution is a human lung carcinogen; however, the components responsible have not been identified. We assessed the associations between PM components and lung cancer incidence.
METHODS: We used data from 14 cohort studies in eight European countries. We geocoded baseline addresses and assessed air pollution with land-use regression models for eight elements (Cu, Fe, K, Ni, S, Si, V and Zn) in size fractions of PM2.5 and PM10. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses and random effect models for meta-analysis.
RESULTS: The 245,782 cohort members contributed 3,229,220person-years at risk. During follow-up (mean, 13.1years), 1878 incident cases of lung cancer were diagnosed. In the meta-analyses, elevated hazard ratios (HRs) for lung cancer were associated with all elements except V; none was statistically significant. In analyses restricted to participants who did not change residence during follow-up, statistically significant associations were found for PM2.5 Cu (HR, 1.25; 95% CI, 1.01-1.53 per 5ng/m(3)), PM10 Zn (1.28; 1.02-1.59 per 20ng/m(3)), PM10 S (1.58; 1.03-2.44 per 200ng/m(3)), PM10 Ni (1.59; 1.12-2.26 per 2ng/m(3)) and PM10 K (1.17; 1.02-1.33 per 100ng/m(3)). In two-pollutant models, associations between PM10 and PM2.5 and lung cancer were largely explained by PM2.5 S.
CONCLUSIONS: This study indicates that the association between PM in air pollution and lung cancer can be attributed to various PM components and sources. PM containing S and Ni might be particularly important.