the annual emission of PM 2.5 by three wheeler suddenly becomes very law with 2002 to 2014 in Delhi give possible reasons
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Answer:
road PM2.5 pollution exposure in multiple transport
microenvironments in Delhi
Rahul Goel a, *
, Shahzad Gani b
, Sarath K. Guttikunda c, d
, Daniel Wilson e
, Geetam Tiwari a
a Transport Research and Injury Prevention Program, Indian Institute of Technology Delhi, New Delhi, 110016, India
b Environmental and Water Resources Engineering, The University of Texas at Austin, TX, USA
c Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Mumbai, 400076, India
d Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, 89512, USA
e University of California, Berkeley, USA
highlights
Measurements of on-road PM2.5 exposures in 11 transport microenvironments in Delhi.
Traveling in auto rickshaw leads to 30% higher exposure rate than in an off-road location.
Inside air-conditioned cars and metro carriages, the exposure rate is the lowest.
PM2.5 mass inhaled per km is 9 times for cycling compared to inside of an AC car.
article info
Article history:
Received 25 February 2015
Received in revised form
12 October 2015
Accepted 12 October 2015
Available online 20 October 2015
Keywords:
PM2.5
Air pollution
Road transport
Traffic
Exposure
Delhi
India
abstract
PM2.5 pollution in Delhi averaged 150 mg/m3 from 2012 through 2014, which is 15 times higher than the
World Health Organization's annual-average guideline. For this setting, we present on-road exposure of
PM2.5 concentrations for 11 transport microenvironments along a fixed 8.3-km arterial route, during
morning rush hour. The data collection was carried out using a portable TSI DustTrak DRX 8433 aerosol
monitor, between January and May (2014). The monthly-average measured ambient concentrations
varied from 130 mg/m3 to 250 mg/m3
. The on-road PM2.5 concentrations exceeded the ambient mea-
surements by an average of 40% for walking, 10% for cycle, 30% for motorised two wheeler (2W), 30% for
open-windowed (OW) car, 30% for auto rickshaw, 20% for air-conditioned as well as for OW bus, 20% for
bus stop, and 30% for underground metro station. On the other hand, concentrations were lower by 50%
inside air-conditioned (AC) car and 20% inside the metro rail carriage. We find that the percent ex-
ceedance for open modes (cycle, auto rickshaw, 2W, OW car, and OW bus) reduces non-linearly with
increasing ambient concentration. The reduction is steeper at concentrations lower than 150 mg/m3 than
at higher concentrations. After accounting for air inhalation rate and speed of travel, PM2.5 mass uptake
per kilometer during cycling is 9 times of AC car, the mode with the lowest exposure. At current level of
concentrations, an hour of cycling in Delhi during morning rush-hour period results in PM2.5 dose which
is 40% higher than an entire-day dose in cities like Tokyo, London, and New York, where ambient con-
centrations range from 10 to 20 mg/m3
.
© 2015 Elsevier Ltd. All rights reserved.
1. Introduction
Majority of the population in Indian subcontinent is exposed to
ambient particulate matter (PM) pollution levels much higher than
World Health Organization (WHO) guidelines (Dey et al., 2012).
According to Global Burden of Disease 2010 study, ambient PM
pollution in India resulted in more than 600,000 deaths in 2010
(Lim et al., 2013). According to a database of PM10 (PM with aero-
dynamic diameter < 10 mm) pollution levels in more than 1600
cities in the world in 2014, more than 40 cities from India are
among the 100 most polluted, with Delhi being the most polluted
of all (WHO, 2014). The annual average PM2.5 concentration for the
period 2012 through 2014, reported by three air quality monitoring
stations located across the city, was 150 mg/m3
, which is