Quantifying the role of the transport sector on observed variations of PM2.5 over the National Capital Territory of Delhi, India. [Industry funded]

Project Background The World Health Organization (WHO) recently announced that particulate matter (PM) now affects more people than any other pollutant. Here, we focus on PM less than 2.5 microns in diameter (PM2.5) as they pose a greater risk to human health via respiratory and cardiovascular diseases. We focus on Delhi, India for three main reasons: 1) according to the WHO it is the most polluted megacity in the world with annual median PM2.5 values typically exceeding 100 micrograms/m3 (cf annual median of 5 micrograms/m3 Edinburgh, UK, 2015), 2) the transportation sector is one of the largest sources (~30%) of PM2.5 in Delhi, and 3) we can take advantage of a new UK-India measurement programme, the scope of which is currently being finalized. Working in Delhi presents numerous scientific challenges not least because of its mix of biogenic, anthropogenic, and pyrogenic gases and particles, high temperatures, and high level of NOx.