“NEW DELHI: Most pollution fights in the city have focused around particulate matter, and understandably so, since it’s the lead pollutant — on most days. However, nitrogen dioxide(NO2) levels are also seeing a gradual rise, often breaching the safe standard.
Delhi Pollution Control Committee’s annual monthly NO2 data between 2014 and 2017 for four stations — RK Puram, Madir Marg, Punjabi Bagh and Anand Vihar — show NO2 levels crossing the safe standard, particularly in the autumn and winter months.” The Times of India

Read it on Delhiair.org:
Delhi air pollution: Why nitrogen dioxide my be your next big headache