Long-Term Exposure to Air Pollutants and Cancer Mortality: A Meta-Analysis of Cohort Studies

Abstract

The aim of this study was to examine the relationship between main air pollutants and all cancer mortality by performing a meta-analysis. We searched PubMed, EMBASE (a biomedical and pharmacological bibliographic database of published literature produced by Elsevier), and the reference lists of other reviews until April 2018. A random-effects model was employed to analyze the meta-estimates of each pollutant. A total of 30 cohort studies were included in the final analysis. Overall risk estimates of cancer mortality for 10 µg/m3 per increase of particulate matter (PM)2.5, PM10, and NO2 were 1.17 (95% confidence interval (CI): 1.11–1.24), 1.09 (95% CI: 1.04–1.14), and 1.06 (95% CI: 1.02–1.10), respectively. With respect to the type of cancer, significant hazardous influences of PM2.5 were noticed for lung cancer mortality and non-lung cancer mortality including liver cancer, colorectal cancer, bladder cancer, and kidney cancer, respectively, while PM10 had harmful effects on mortality from lung cancer, pancreas cancer, and larynx cancer. Our meta-analysis of cohort studies indicates that exposure to the main air pollutants is associated with increased mortality from all cancers.

PM2.5 exposure on daily cardio-respiratory mortality in Lima, Peru, from 2010 to 2016

“…The database included 109,951 recorded deaths from respiratory and circulatory disease, between January 2010 and December 2016. We excluded four districts (10,228 deaths) because the model may be inaccurate above 375 m (as noted above), and also excluded some other observations because pollution on some days could not be estimated due to lack of satellite coverage (12,753 deaths) (see below); the remaining sample was 86,970.…”

“…Epidemiological studies conducted mainly in developing countries have associated PM 2.5 with all cause and cause-specific mortality [2][3][4][5][6][7]. These studies have evaluated short-term and long-term PM 2.5 exposure on mortality, primarily cardiovascular and respiratory deaths [3,4,8], but also some kinds of cancer [9][10][11]. Based on epidemiological evidence, the World Health Organization (WHO) estimated that air pollution is associated with premature deaths related to ischemic heart disease, strokes, chronic obstructive pulmonary disease, acute lower respiratory infections and lung cancer [2-4, 6, 7, 9].…”

PM2.5 exposure on daily cardio-respiratory mortality in Lima, Peru, from 2010 to 2016.

“…We excluded four districts (10,228 deaths) because the model may be inaccurate above 375 meters (as noted above), and also excluded some other observations because pollution on some days could not be estimated due to lack of satellite coverage (12,753 deaths) (see below); the remaining sample was 86,970.…”

“…Epidemiological studies conducted mainly in developing countries have associated PM 2.5 with all cause and cause-specific mortality [2,3,4,5,6,7]. These studies have evaluated short-term and long-term PM 2.5 exposure on mortality, primarily cardiovascular and respiratory deaths [3,4,8], but also some kinds of cancer [9,10,11].…”

PM2.5 exposure on daily cardio-respiratory mortality in Lima, Peru, from 2010 to 2016.

“…Epidemiological studies conducted mainly in developing counties have associated PM 2.5 with all cause and cause-specific mortality [2,3,4,5,6,7]. These studies have evaluated short-term and long-term PM 2.5 exposure on mortality, primarily cardiovascular and respiratory deaths [3,4,8], but also some kinds of cancer [9,10,11].…”