Long-term Exposure to Ambient Air Pollution and Incidence of Brain Tumor: the European Study of Cohorts for Air Pollution Effects (ESCAPE)

Abstract

Background

Epidemiological evidence on the association between ambient air pollution and brain tumor risk is sparse and inconsistent.

Methods

In 12 cohorts from six European countries, individual estimates of annual mean air pollution levels at the baseline residence were estimated by standardized land-use regression models developed within the ESCAPE and TRANSPHORM projects: particulate matter (PM) ≤ 2.5, ≤ 10, and 2.5–10 μm in diameter (PM_2.5, PM₁₀, and PM_coarse), PM_2.5 absorbance, nitrogen oxides (NO₂ and NO_x) and elemental composition of PM. We estimated cohort-specific associations of air pollutant concentrations and traffic intensity with total, malignant and nonmalignant brain tumor, in separate Cox regression models, adjusting for risk factors, and pooled cohort-specific estimates using random-effects meta-analyses.

Results

Of 282,194 subjects from 12 cohorts, 466 developed malignant brain tumors during 12 years of follow-up. Six of the cohorts had also data on nonmalignant brain tumor, where among 106,786 subjects, 366 developed brain tumor: 176 nonmalignant and 190 malignant. We found a positive, statistically non-significant association between malignant brain tumor and PM_2.5 absorbance (Hazard Ratio and 95% Confidence Interval: 1.67; 0.89–3.14 per 10 ^–5/m ³), and weak positive or null associations with the other pollutants. Hazard ratio for PM_2.5 absorbance (1.01; 0.38–2.71 per 10 ^–5/m ³) and all other pollutants were lower for nonmalignant than for malignant brain tumors.

Conclusion

We found suggestive evidence of an association between long-term exposure to PM_2.5 absorbance indicating traffic-related air pollution and malignant brain tumors, and no association with overall or nonmalignant brain tumors.

from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2vIUczO