A study conducted by Pollution Control Board in 2016 revealed over 200 tonnes of carbon monoxide were emitted by vehicles every day in Hyderabad, posing a threat to citizens' health. In the Nineties, it was less than 130 tonnes a day. Particulate Matter levels too rose from over 1.9 tonnes to over 11 tonnes a day in last 20 years.

Traffic cops simply check whether the motorist is carrying a pollution-under-check (PUC) certificate and let him go. They do not have equipment to check whether the vehicle is emitting pollution more than stipulated norms. What's more, there is no online facility for police to measure whether the PUC flaunted by the motorist is authentic.

Environmentalists said it's high time the government replaced obsolete roadside pollution testing units with latest machinery. Pollution Control Board and RTA officials should check whether these mobile testing units are defunct and illegally issuing certificates. "Advanced technology has hit the market which can tell exact pollution levels emitted by vehicles," said noted environmentalist K Purushotham Reddy.

He said there is a possibility that vehicles with PUCs are emitting higher levels of pollution. According to him, the drive against vehicular pollution should be intensified and made a continuous affair. Air pollution due to vehicle emissions is an issue that poses threat to lives of not just road users, but all citizens. "It should not be taken up as a ritual. Every time a vehicle is stopped for checks, motorists should be told to produce PUCs," he said.

Speaking to TOI, deputy commissioner of police (traffic) A V Ranganath said there was a proposal to replace existing mobile testing units. The project envisaged installing hi-tech equipment to display online data on PUC certificates to enable traffic cops to retrieve data on hand-held equipments. However, the project is pending and a green signal from the government is expected soon.