Exposure to PM 2.5 constituents and risk of adult leukemia in Denmark. - GreenMedInfo Summary
Exposure to PMconstituents and risk of adult leukemia in Denmark: A population-based case-control study.
Environ Res. 2020 Nov 3:110418. Epub 2020 Nov 3. PMID: 33157111
BACKGROUND: Leukemia is one of the most common forms of hematologic malignancy, which can affect people of all ages. We previously showed an association between exposure to ambient particulate matter 2.5μg (PM) and risk for leukemia in adults. The aim of this study was to investigate which PMconstituents were responsible for our previous observation.
METHODS: This is a nationwide register-based case-control study. We identified 14,983 persons diagnosed with leukemia at age 20 or above, 1989-2014, in the Danish Cancer Registry. We selected up to four sex and age-matched controls per case at random from the entire Danish population (n=51,613). We modelled concentrations of ambient PMand its constituents at the addresses of cases and controls for the 10-year period before index date with a state-of-the-art multiscale air pollution modeling system. We used conditional logistic regression to estimate odds ratios (ORs) adjusted for individual and neighborhood level socio-demographic variables.
RESULT: The results showed higher risk for overall leukemia in association with interquartile range exposure to PM(OR=1.09; 95% CI: 1.02, 1.17), black carbon (BC) (OR=1.02; 95% CI: 1.00, 1.03), secondary inorganic aerosols (SIA) (OR=1.15; 95% CI: 1.03, 1.29) and its components ammonium (NH) (OR=1.08; 95% CI: 1.00, 1.17) and nitrate (NO) (OR=1.08; 95% CI: 1.02, 1.14). In leukemia subtype analysis, statistically significant associations were found for AML with PM(OR=1.14; 95% CI: 1.00, 1.29), BC (OR=1.03; 95% CI: 1.00, 1.07), SIA (OR=1.23; 95% CI: 1.01, 1.51), NH(OR=1.16; 95% CI: 1.01, 1.34) and NO(OR=1.12; 95% CI: 1.01, 1.24). The association between PMand leukemia persisted in two pollutants models including sum of primary emitted black and organic carbon (BC+OC), secondary organic aerosols (SOA), or sea-salt. The association between black carbon (BC) and leukemia persisted in two pollutants models including organic carbon (OC). The three pollutant model with sulfate (SO), NHand NOshowed an association with NObut not with SOor NH.
CONCLUSION: Ambient concentrations of the PMcomponents BC, NHand NOat the residence showed associations with risk of incident leukemia in adults.