The Association between Outdoor Air Pollution and Lung Cancer Risk in China: Trends in the Last Decades and Sex Differences

Abstract

Background: This study aims to identify and examine lung cancer risks and mortality burdens associated with air pollutants, including PM10, NO2 and SO2, in China. Methods: The study population comprised a population from seven representative cities located in different regions of China. The yearly average values (YAV, μg/m3) of the PM10, NO2 and SO2 levels were extracted from CSYB for each selected city from 2006 to 2014. Data collected in the Chinese Cancer Registration Annual Report (CCRAR) provide lung cancer incidence and mortality information. The associations of PM10, SO2 and NO2 with the lung cancer incidence rate and mortality rate were analyzed by using a two-level normal random intercept regression model with a five-year moving window of past exposure to each pollutant. Findings: The male age-adjusted incidence rate (MAIR) and male age-adjusted mortality rate (MAMR) decreased significantly from 2006 to 2014. The yearly average values of PM10, SO2 and NO2 consistently and significantly decreased from 2006 to 2014. Compared to SO2 and PM 10, NO2 at an exposure window of 2~3 years had the highest RR values for the MAIR (RR=1.57, 95% CI: 1.19-2.05, p=0.002), MAMR (RR=1.70, 95% CI: 1.32-2.18, p=0.0002) and FAMR (RR=1.27, 95% CI: 1.08-1.49, p=0.003). Interpretation: Our findings suggested that air pollutants may be related to the occurrence and mortality of lung cancer. NO2 was most strongly associated with the risk of lung cancer, followed by SO2. Air pollutants have the strongest effect on the incidence and mortality of lung cancer with a 2-3 year lag. Funding Statement: Key Project of Hunan Provincial Science and Technology Department (2014TT1001), Project of Hunan Health Commission (C2014-34), Project of Hunan Health Commission (20201665), Project of Chinese Society of Clinical Oncology ( YHR2018- 234), Project of Hunan Cancer Hospital (No. A2011-03). Declaration of Interests: No interests to declare.