Chennai, Feb 5: Air quality in the coastal city of Chennai was consistently poor in the past two months with pollution level hitting ‘Hazardous’ level in many areas. Air quality touched poor or unhealthy levels in Alandur and Manali on Monday. Several areas in Chennai witnessed poor and hazardous quality air on Sunday.

According to an international expert, levels of toxic metal manganese in the air during this period averaged 55 per cent higher than they were averaged in April 2017, whereas lead levels averaged nearly three times higher in two months than they were averaged in April.

Mark Chernaik, a scientist associated with the Environmental Law Alliance Worldwide who studied the reports, told news agency IANS that five of the samples in Chennai in the past two months reached a level of ‘very unhealthy’ and two of them ‘hazardous’ under the US Environmental Protection Agency (EPA) Air Quality Index.

According to Chernaik, the levels of PM 2.5 (a crucial indicator of dangerous pollution) in December and January averaged 165 Aug/m3, 35 per cent higher than PM 2.5 averaged in April. He says the air quality in Chennai seems heavily impacted by re-suspension of dust.

“The emissions from the paved road dust contribute significantly to the pollution load as far as PM 10 is concerned. The contribution from the vehicular sources towards PM is only around 10 per cent in Chennai,” he said.

Aluminum, iron, calcium and silicon, enriched in coal ash are indicators of pollution caused by re-suspended dust. Levels of aluminium, iron, calcium and silicon combined constituted roughly 15 per cent of PM 2.5 in ambient air samples collected both in December and January and in April 2017. (With IANS inputs)