Global Health Hazards From Human-Derived Volatile Organic Compounds Amid Emission Variability

Health risks from high air pollution exposure remain challenging despite pollution control strategies. Health hazards caused by particulate matter and ozone have been reported for the past three decades. Here, we report the hazard quotient for Volatile Organic Compounds (VOCs) causing non-carcinogenic risk globally using chemistry-climate model simulations. We report hazard quotient (HQ) for three scenarios: (a) baseline scenario, (b) continued increasing emissions leading to doubling of anthropogenic VOCs (DVOCS), and (c) mitigation scenarios where emissions are reduced to half (HalfVOCS). Interestingly, we report that long-term ambient exposure to VOCs increases non-carcinogenic health risk by up to 36% in the high-emission scenario. Hazardous VOCs such as benzene, formaldehyde, hydrogen cyanide, and acetonitrile remain at levels that pose chronic risks to large populations. Benzene and formaldehyde pose the greatest hazards, with maximum HQ ranging from 1.4 to 2.0. Additionally, the DVOCS scenario increases the risk to the exposed population by 18.6%-21.5% in northern India and eastern China, and by 10.7% in West-Central Africa. Conversely, the HalfVOCS scenario shows a decrease in the exposed population of -3 to -21%. We estimate that approximately a million people face chronic respiratory and neurological risks from current ambient VOCs levels. Our findings demonstrate that VOCs exposure constitutes a major driver of the global disease burden, necessitating immediate international emission-reduction strategies.