Background: In China, the incidence of lung cancer is notably elevated. As reported by the International Agency for Research on Cancer, China saw an estimated 815,563 new cases of lung cancer in 2020, comprising 17.9% of all new cancer cases, and 714,699 deaths, accounting for 23.8% of all cancer-related deaths. Numerous studies have demonstrated a strong relationship between particulate matter (PM2.5) pollution and lung cancer.Assessment of the cancer burden due to PM2.5 Pollution is crucial in guiding policymakers to design effective national cancer control programs.  Exposure to PM2.5 can occur both indoors and outdoors, and both have negative health effects and increase the risk of lung cancer.Separately assessing indoor and outdoor PM2.5 will provide a more accurate estimation of the impact of PM2.5 on lung cancer burden in different environments and is essential for understanding the sources and determinants of lung cancer burden. Most studies evaluating cancer burden attributed to ambient fine particulate matter in China were based on incidence, prevalence or mortality rates. Few has utilized the DALYs, a well-accepted metric for assessing (or to measure) the health consequences of environmental pollution and overall burden of a disease of a population. It takes into account both years of life lost due to premature mortality and years of healthy life lost due to disability caused by a particular disease or risk factor. Thus, DALYs capture the full impact of a disease on both mortality and morbidity.
Objectives: To examine whether the disease burden of lung cancer attributable to PM2.5 pollution  has changed in China from 1990 to 2019.
Methods: We applied Joinpoint regression models to disability-adjusted life years (DALYs), to assess the time trends and estimate the impact of PM2.5 on the overall disease burden of lung cancer. Furthermore, age-period-cohort models were conducted to assess the relationships between lung cancer DALYs attributed to PM2.5 exposure and attained age, calendar period, and birth cohort trends of in China from 1990 to 2019.
Results: Lung cancer DALYs attributable to HPE decreased with the average annual percent change (AAPC) of 2.9% per 100,000 population, while those attributable to APE increased (AAPC: -4.7% per 100,000 population) over the past 30 years. The burden of lung cancer in terms of DALYs in males were higher than in females, and it demonstrated an age-dependent increase. The period and cohort effects also had a significant impact on the DALYs rates of lung cancer attributable to APE, indicating an overall increase in lung cancer DALYs for all age groups in each year.
Conclusions: This study highlights the need for effective strategies to reduce PM2.5 exposure in China, particularly from outdoor sources. Gender differences and age, period, and cohort effects observed in the study provide valuable insights into long-term trends.