Insight into festival ushered pollutants in Indian metro cities: concerns, differences and similarities

Abstract Multi-fold increase in particulate matter (PM) and trace gases in connection with celebrations associated with firework displays is a matter of concern all over the world. The current study, commenced as an assessment of pollutant escalation due to the key Indian festival event through observations online and cumulative sampling along with chemical speciation of particulates and trace gases over four SAFAR networked mega and metro cities of India viz. Delhi, Ahmedabad, Mumbai and Pune. It is seen that the amplitude and duration of the event is largely dependent on the attitude and culture of the inhabitants of each city; PM2.5 and PM10 in Delhi are observed to increase by 353% and 213% respectively. In Pune and Ahmedabad, enhancement in PM2.5 is half of that of Delhi while the effect in Mumbai is just 1/7th of Pune, where variation is atypical to other cities. The enhanced pollution levels may lead to chronic or acute health emergency if they persist for long hours under unfavourable weather conditions. Metal content (K, Mg, Na, Mn and Pb) in PM 2.5 has nearly doubled in all the cities; huge increase in pulmonary range particulates and the steep elevation in their heavy metal content is a matter of concern due to their toxicity and acute health effects. Trace gases, NOx and CO which are also a health worry indicate a continuing increase due to the festival episode that happened in a non-conducive weather.