New Delhi: Their city already infamous as one of the world’s most polluted cities, Delhi’s residents are breathing unacceptable levels of poisoned air, according to a study by the Centre for Science and Environment (CSE).

People in the capital are exposed to 2-4 times higher levels of toxic air while travelling in mass modes of transport such as buses, metro rail, autos or even while walking.

In first two weeks of February, the non-profit organisation monitored air pollution levels in buses, autos, metro rail and while walking to assess the amount of pollution that average citizens are exposed to during their daily commute. The monitoring was carried out during morning and evening traffic peak hours.

“It helped us understand how much pollution people breathe on a daily basis in Delhi while travelling. Our data is quite shocking," said Anumita Roychowdhury, CSE’s executive director of research and advocacy, and head of its Right to Clean Air campaign.. “We have found that daily personal exposure to toxic air is significantly higher than the background ambient air pollution monitored by the Delhi Pollution Control Committee (DPCC). This is a serious risk to public health,"

This toxic risk can be reduced only if a stringent clean air action plan is implemented in a time-bound manner.

As per the CSE study, exposure in all transport modes is very high and the average levels recorded are 2-4 times higher than the background levels reported by DPCC.

The study showed that open modes like autorickshaws, walking and cycling have the highest exposure. But as per the CSE analysis, underground metro (rail) with sealed environment showed lower levels of pollution compared with overhead metro.

The study also revealed that pollution levels peak near junctions and in traffic jams. “In a traffic jam on a stretch close to Paharganj, levels peaked at 1,170 microgramme per cubic metre. At a traffic jam near Govindpuri Metro Station, the peak level was 725 microgramme per cubic metre. A cycle rickshaw ride on NH 24 in close proximity to truck traffic recorded a range of 651 to 2,000 microgramme per cubic metre," said the study.

But if anyone believed that pollution levels are high only if they are travelling in the open, then they need to rethink because even cars are not of much help. During the study, monitoring inside the car was carried out during off-peak hours where the average levels were found to be double the ambient levels.

The study also showed Delhi traffic police managing traffic signals are also breathing unacceptably high levels of polluted air. As per the monitoring carried out at the ITO crossing, peak exposure was eight times the ambient level.

Calling pollution levels in national capital as a critical situation, CSE said that in other countries, if cities are afflicted in a similar manner, immediate steps are taken to reduce the number of cars, shut industrial units, and close down schools.

It suggested a series of steps to the new Delhi government led by the Aam Aadmi Party (AAP) to tackle the pollution like implementing new emissions standards, improving public transport including Delhi’s target of 11,000 buses, restraining growth of cars with parking limits and taxes, stringent measures for older vehicles and road-worthiness tests for private vehicles.