The Assessment of VOCs Health Risks for Various Indoor Living Scenarios in Hong Kong

Indoor concentrations of volatile organic compounds (VOCs), such as aromatic hydrocarbons, alkanes, and formaldehyde, are higher than outdoor levels. Exposure to these pollutants has raised ongoing concerns about their long-term health impacts. Assessing indoor air quality and associated health risks requires an in-depth understanding of human lifestyles and comprehensive analysis of VOCs. Key to this is identifying critical pollutants and establishing population exposure scenarios across different indoor environments. Hong Kong serves as a representative urban case study, with a population density of approximately 50,000 residents per square kilometer. This study collected air samples from various microenvironments in Hong Kong, including residences, activity centers, transportation settings, and outdoor areas. The concentrated VOCs were re-volatilized and injected into three gas chromatography systems for analysis, detecting 90 VOCs along with concentrations of carbon monoxide and carbon dioxide. The results revealed significant differences in VOC profiles across different environments: the main components of alkenes were isobutene, propene, isoprene, and ethylene; alkanes primarily consisted of ethane, isobutane, propane, and n-butane, with indoor concentrations of propane significantly higher than outdoor levels. This study conducted a risk assessment of indoor pollutants. The results showed that the cumulative carcinogenic risks for both children and adults exceeded acceptable limits. The cumulative hazard quotient for adults also surpassed safety thresholds in multiple exposure scenarios. These findings indicate that future VOC risk assessments must incorporate predicted compounds and scenario-specific exposure evaluation systems.