Effect of the curfew on air quality in Colombo and Kandy
By Dr Rohan Jayaratne, Dr Gayan Bowatte and Mahesh Senarath Air Quality Monitor installed in Kandy The COVID-19 situation has affected normal activities all over the world. There are fewer motor vehicles on the roads and many factories remain shut, giving rise to significant decreases in airborne pollution. For example, Beijing has reported visible blue skies after many years. In some regions in Northern India, residents have been able to see the Himalayas from afar for the very first time. Residents in Colombo have been enjoying spectacular views of Adam’s Peak and the central hills. So, by how much have the pollution levels in Sri Lanka decreased during the recent curfew period? Air pollution occurs in the form of gases and small particles. The particle pollution in the atmosphere is generally expressed as PM2.5, which is the mass per unit volume of particulate matter on particles that are smaller than 2.5 micrometre in diameter. Normally, the PM2.5 level in the city of C...