Heavy industrial activity in the Indo-Gangetic belt has led to a rapid degradation of air quality in the region, with the city of Varanasi being recorded as having the most toxic air in the country, a report by a group of organisations has said. Cities such as Varanasi and Allahabad recorded zero good air quality days during the period in 2015 for which they were monitored by the organisations, IndiaSpend reported.

The report – compiled by the Centre for Environment and Energy Development, Care4Air and IndiaSpend – used national quality standards to measure the levels of particulate matter in the air. It was found that cities across Uttar Pradesh reported conditions ranging from “very poor” to “severe” – the level of air quality with a dangerous enough impact to affect healthy people.

Aishwarya Madineni, an author of the report, said cities such as Varanasi needed a “surgical strike” on air quality. “Child specialists, when consulted, have concluded there has been an eightfold rise in the respiratory ailments in the city,” Madineni said. Researchers said pollution sources such as the seasonal burning of biomass and brick kilns also contributed the worsening air quality of the region.

Care4Air chief campaigner Ekta Shekhar said there was no “comprehensive action plan on air pollution”, adding that “immediate steps” needed to be taken to fight the issue. “Cities and states need to work together to formulate a regional action plan.” Meanwhile, increased levels of pollution were recorded in Delhi as well, with readings on Monday showing a 116% increase in the concentration of PM 2.5 (particulate matters that are 2.5 or less than 2.5 microns in diameter), The Times of India reported.

Agencies from around the world have recorded alarming levels of pollution in the previous two months. In its effort to cope with its worst winter pollution in a decade, the French capital of Paris introduced traffic restrictions, including an odd-even scheme similar to the one implemented in Delhi earlier this year. The president of an environmental group said there were more than 48,000 premature deaths in France each year because of air pollution.