COMMUTERS’ EXPOSURE TO PM2.5 AND PM1.0 IN VARIOUS MODES OF TRANSPORTATION

Abstract

In metropolitan cities like Delhi, Mumbai etc, a large proportion of exposure to airborne pollutants, in particular particulate matter, is likely experienced during daily commuting trips due to the proximity to a number of pollution sources (vehicular traffic, industry, construction sites, etc).Brief periods of exposure to high concentrations of air pollution may have significant health impacts. Therefore it is important for better understanding of the variability in pollutant concentrations across available transport modes for commuters and authorities. Unfortunately, personal exposure to particle pollution in the transport microenvironment of Delhi to date has not been well documented. The present study analyses exposure concentrations of particulate matter (PM1.0, PM2.5), measured along a selected route in the district of Delhi. Real-time monitoring of selected parameters was done using portable instruments (Haz Dust EPAM-5000) capable of measuring real time concentrations during trips on four different modes of transport (Ac Cab, Auto Rickshaw, DTC Bus and Non Ac Cabs). PM measurements in each mode of transportation were repeated in morning, afternoon and evening hours and monitoring has been done for each mode twice. Trip averaged pollution exposure to commuters for PM2.5 was highest for DTC bus (819.44% higher concentration than ac cabs) in morning hours followed by auto rickshaw, Non Ac Cab and Ac Cab. Whereas in evening hours exposure in descending order was Auto Rickshaw (503.15% higher concentration than ac cab), DTC Bus, Non Ac Cab and Ac Cab. During the afternoon hours concentration of PM2.5 was highest for Auto Rickshaw. For PM1.0 trip averaged pollution exposure to commuters was highest for Auto Rickshaw (364.3% higher concentration than ac cab) in morning, afternoon and evening hours (402.4% higher concentration than ac cab) followed by DTC Bus, Non Ac Cab and Ac Cab. Except for Ac Cab higher exposure concentrations was observed for all the remaining three modes of transportations. The poor vehicle emission controls, poor vehicle maintenance, plus theslow moving traffic condition with frequent stops are believed to be the major causes of high in vehicle levels in somepublic commuting trips.