Associations between non-methane volatile organic compounds and cause-specific mortality across 14 major categories

Non-methane volatile organic compounds (NMVOC) are widespread ambient pollutants with documented toxicological properties, yet population-level evidence on their long-term health impacts remains limited. We analyzed data from 394,153 adults in a large prospective cohort study. Individual exposure to NMVOC was estimated by linking residential addresses with modeled concentrations. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) per standard deviation (SD) increase in exposure for 14 major mortality categories and 97 specific causes. Population attributable fractions were calculated to characterize the potential mortality burden, and accelerated failure time models assessed the impact of exposure on timing of death. Over a median follow-up of 13.71 years, 32,310 deaths occurred. Long-term NMVOC exposure was associated with increased mortality risks across a range of disease systems. Of the major disease categories, mortality from respiratory system diseases exhibited the strongest and positive association (HR = 1.048, 95% CI: 1.028-1.069). Notably, subtype analysis highlighted particularly strong associations with asthma (HR = 1.130) as well as phlebitis and thrombophlebitis (HR = 1.129). The estimated population attributable fractions of mortality associated with NMVOC exposure ranged from 2.243% for circulatory diseases to 7.673% for other symptoms. In addition, accelerated failure time models suggested that higher exposure levels were associated with differences in survival time corresponding to 1.517 to 3.935 years earlier mortality. These findings suggest associations between long-term NMVOC exposure and increased and earlier mortality across multiple organ systems, highlighting potential public health relevance.