Global trends and projections of tracheal, bronchial, and lung (TBL) cancers associated with occupational exposure to diesel engine exhaust (DEE): insights from the Global Burden of Disease (GBD) 2021 Study for 1990 to 2021 and projections to 2035.

Background: Occupational exposure to diesel engine exhaust (DEE) is recognized as a major causative agent of tracheal, bronchial, and lung (TBL) cancers. This source emits hazardous substances, including carcinogenic compounds such as polycyclic aromatic hydrocarbons and benzene. In 2012, the International Agency for Research on Cancer (IARC) classified DEE as a Group 1 human carcinogen. However, the global disease burden due to occupational exposure-related TBL is not well understood. Utilizing the Global Burden of Disease (GBD) data for 2021, we examined the trends in mortality, disability-adjusted life years (DALYs), and standardized rates of occupational DEE-associated TBL from 1990 to 2021, with projections extending up to 2035. The study aims to identify regional, gender, and socioeconomic disparities to inform the creation of effective prevention and control strategies. Methods: A global analysis of occupational DEE-related TBL cancers was conducted using data from the GBD 2021 study. The analysis involved estimation of deaths, DALYs, and age-standardized rates [age-standardised mortality rate (ASMR)/age-standardized DALY rates (ASDR)] for 204 countries and regions worldwide. Joinpoint regression models were employed to calculate average annual percentage change (AAPC), while decomposition analyses were employed to explore the effect of population growth, ageing, and epidemiological changes on disease burden. Furthermore, frontier analyses were employed to examine the relationship between DALYs and the socio-demographic development index (SDI) in each country, whereas the Bayesian age-period-cohort (BAPC) modelling was employed to project the burden of disease to 2035. Results: From 1990 to 2021, the global number of occupational DEE-related TBL deaths increased from 7,896 to 21,620, and DALYs increased from 249,939 to 630,161. However, moreover, ASMR decreased slightly (0.31 to 0.24/100,000). The highest ASMR and ASDR values were observed in East Asia (0.51 and 14.67/100,000) and the lowest in western sub-Saharan Africa (0.04 and 1.22/100,000). The findings revealed a twofold higher disease burden in males compared to females, most notably in middle SDI regions. Decomposition analysis indicated that population growth (47.91%) and ageing (46.31%) were the primary drivers. Projections indicate that global deaths are expected to increase to 23,100 by 2035, while ASMR is likely to decrease to 0.410 per 100,000 people. Conclusions: The global burden of TBL cancer is significantly influenced by occupational DEE exposure, exhibiting notable regional, socioeconomic development level and gender disparities. Although the disease rate per person is going down, the total number of cases is still rising. This shows a clear need for better workplace safety rules, cleaner technology, and focused efforts to prevent avoidable illness.