π¨ Cleaner cars might hide new pollution risks
Stricter vehicle regulations are reducing total volatile organic compounds (VOCs) in exhaust emissions. Researchers analyzed seven gasoline vehicles, including one non-plug-in hybrid, using a specific framework. Between China IV and China VI standards, total VOC emissions dropped significantly, yet OVOCs increased to 35% of total VOCs. One hybrid released nearly double the OVOCs compared to its conventional counterpart during low-speed hot starts. This suggests total emission numbers can mask changes in hazardous chemical makeup, needing more species-specific rules.