Besides, the RTO has also seized 7,288 for not having the mandated pollution clearance certificate and other such documents needed to ply on city roads. The transport office accrued over Rs 8 lakh as fines from defaulters between April 1, 2014 and March 31, 2015.

There are a total of 6.65 lakh vehicles registered in Agra, out of which 5.96 lakh are run on petrol while another 63,396 are diesel-run. A miniscule 785 are run on CNG.

Such a high number of vehicles without the mandatory pollution clearance certificates has resulted in the city air quality taking a serious hit. Anand Kumar Anand, regional officer of Uttar Pradesh pollution control board, said, "RTO and traffic police need to be more stringent against defaulters in order to rein in air pollution levels in the city. They should phase out all vehicles from roads that either don't have a proper vehicle maintenance record or emit toxic fumes."

"And since Agra is a sensitive area housing world heritage sites, the local administration should follow NGT's Delhi-specific order, in which diesel vehicles over ten years old have been banned," he added.

In 2014, particulate matter 10 (PM10) levels in four zones of Agra - Nunhai, Rambagh, Etmad-ud-daulah and Taj Mahal - were way above the permissible limit. The permissible limit of PM-10 is 60, but Nunhai recorded the maximum at 212, while Rambagh followed with 175.

The Mughal era heritage site Etmad-ud-daulah registered PM-10 level at 190 and Taj Mahal recorded it at 152.

A K Singh, senior regional transport officer (RTO) told TOI: "Though we have 28 Vahan Pradushan Janch Kendra (VPJK) or vehicle pollution inspecting centers across the city, there still are scores of vehicle owners who blatantly flout rules. As per law, every vehicle, whether it is a two-wheeler or a heavy duty 18-wheel truck, needs to renew their pollution clearance certificates every six months."

When asked about additional steps taken to tackle the problem like raising awareness on the issue, Singh said there was no such plan as of now.