A206-01
A New Approach to Source Apportionment of PM2.5 based on Toxicity of Constituents: A Case Study of Delhi, India

Tuesday, 15 December 2020: 20:30
Virtual
Ashutosh Kumar Pathak, Mukesh Sharma and Pavan Kumar Nagar, Indian Institute of Technology Kanpur, Civil Engineering, Kanpur, India
Recorded Presentation
Abstract:
The premise of this study is that PM2.5 control decisions should be based not only on the quantum of pollution but also consider the toxicity indicators of emitting sources. The new approach has applied a toxicity-based framework, which is different from the conventional practice of conducting only mass-based source apportionment as all particles are not equally toxic. It is important to look deeper into the chemical constituents of the particle to understand toxicity and harm level.

The current methods for source apportionment of ambient PM2.5 are receptor and dispersion modelling. The new approach goes into the constituents of PM2.5. We have considered 15 cancer-causing constituents for cancer potential and 45 constituents for chronic health effects. The developed approach has been applied to the city of Delhi, where the detailed chemical composition of PM2.5 was available.

First traditional source apportion was done using USEPA’s CMB 8.2 model. Total of eleven sources was found to contribute to PM2.5 mass. The each of cancer-causing and other constituents, within each of the sources were apportioned. The apportioned constituents were linked to cancer and chronic health endpoints to obtain unit-less cancer and chronic health effect potential. The unit-less health potential of each constituent within each source was simply added up to obtain the net health effect potential of each source.

Presence of chromium and dibenzo(a,h)anthracene were as identified as the main toxicity causing constituents. The analysis of net health potential for cancer showed that PM2.5 sources of paved road dust (25%), coal-based power plants (20%), diesel vehicles (19%), and gasoline vehicles (12%) were the primary sources. While for chronic potential paved road dust contributed 28%, followed by coal-based power plants (24%) and solid waste burning (12%).

Paved Road dust is not only the single largest source but also has the highest cancer and chronic health effect potential. It was further determined that mechanical sweeping of the main roads if done thrice a month, the road dust emission will be reduced by 23%, which reduces the carcinogenic potential by 6% and chronic potential by 7%.

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