Source apportionment of VOCs at the petrol pumps in Kolkata, India; exposure of workers and assessment of associated health risk

Ambient air quality at five busy petrol pumps in Kolkata, India is monitored for mono-aromatic hydrocarbons and carbonyls. Among the measured volatile organic compounds, toluene and formaldehyde were the most abundant. Source apportionment using chemical mass balance identified exhaust from roadway and refueling as the major sources. Monitoring of the service station workers revealed that the average exposure level for benzene and toluene were 3.9 and 5.5 fold higher than the ambient air. The integrated lifetime cancer risks due to benzene, ethylbenzene, formaldehyde and acetaldehyde and the overall hazard index due to chronic exposure to some hazardous volatile organic compounds are 1.48E−04 and 2.3 indicating the probability of cancer as well as chronic health effect on the workers exposed.