There's one simple thing India can do to check pollution

The quality of air we breathe in Delhi is not acceptable by any standards. Especially during winters, the level of pollutants goes up significantly due to meteorological adversity. However, it is not the meteorology to be blamed, but the emissions released by various sources present in Indian cities and their surroundings.

Excessive growth of vehicles in cities is an important factor contributing to the toxic air. In a city like Delhi, the transport sector accounts for almost 25 per cent of PM2.5 concentrations, while in Bangalore it contributes up to 50 per cent.

While the standards for newer vehicles have been progressively made more stringent, the standards for maintaining these emissions throughout the useful lives of vehicles have not seen great improvements.

Consequently, the share of older vehicles in the emission inventories of the vehicular sector is immense. Also, in the absence of an effective inspection and maintenance system, the on-road reduction in emissions cannot be ensured even with the introduction of cleaner fuels and vehicles. Evidently, there is an urgent need to improve the inspection and maintenance (I/M) system for the vehicular fleet in India.

Currently, in India, we have a pollution under control (PUC) programme for inspection of vehicles plying on roads. Vehicles are tested for pollutants like carbon monoxide, hydrocarbons and the density of the soot emitted from the tailpipe.

The tests are conducted by licensed PUC operators, working in small, often inadequate capacities, at petrol pumps, garages, and workshops. The current PUC testing mechanism has bottlenecks in terms of compliance; measuring instruments and the methodology used for measurement.

According to our recent study at The Energy and Resources Institute (TERI), the percentage of vehicles coming for PUC testing itself is quite low. Then there are questions over calibration of equipment used for PUC testing and audit requirements by the authorities concerned.

Lastly, PUC testing procedures and measuring instruments used in India are dated in the present context. As a result, polluting vehicles may go undetected even after successful PUC testing. In the year 2015-16, in Bangalore, more than 99 per cent of vehicles passed the PUC test based on smoke emissions from the tailpipe.

Current testing technology and methodology is inadequate to detect high emitting vehicles. Countries around the world have made tremendous progress in improving testing methodologies which are more effective in detecting pollution.

Vehicles are now being tested with improved technologies and many countries use loaded tests which are much closer to the real world emissions of vehicles, as compared to idle mode testing which is currently undertaken in India.

The ministry of road transport and highways has taken positive steps in improving the I&M system of in-use vehicles in India. Firstly, an on-board diagnostic system (OBD) was introduced in India with BS-III passenger cars and later a more sophisticated OBD II was introduced in BS-IV diesel vehicles and passenger cars.

OBD monitors the functioning of vehicle components, which can potentially influence the emissions of pollutants. Thus, it could be an important development and game changer for inspecting on-road vehicles.

The relevance will increase in future as a more sophisticated version of OBD will be introduced. OBD can play an important role in screening the vehicles which should then be inspected on rigorous loaded mode tests.

OBD-based testing centres are needed to be established in India after giving due considerations to anti-tampering mechanisms; guidelines and standards for testing; and training of personnel. The vehicles failing OBD tests should be screened out and sent to the inspection and certification (I&C) centre for rigorous loaded mode-testing.

The automated I&C centres are being planned to be set up by the ministry all over the country for inspection of commercial vehicles; some of them are already functional. These large facilities are automated to reduce manipulation by testing staff.

To test all the vehicles (including private vehicles) in Delhi, 125 such centres would be required, needing significant investment and land. However, a lesser number of I&C centres would be required if high emitting vehicles are screened out after the OBD testing.

Meanwhile, the older fleet of vehicles without OBD systems should continue to be tested at the existing PUC centres. However, there is a need to make PUC norms more stringent. It is also needed to improve technologies and procedures for testing.

Smoke-opacity testing for diesel vehicles needs to be changed with technologies like laser light spectroscopy (LLSP) for particulate matter emissions, considering its higher accuracy in detecting PM.

Moreover, there are no standards or testing procedures for measuring oxides of nitrogen from in-use vehicles. Technologies like non-dispersive ultraviolet (NDUV) spectroscopy should be explored for measurement of NOx for its control.

It should be noted that these testing centres would eventually become obsolete in the next 20 years as vehicles without OBD retire from the fleet.

Conclusively, India in a transition phase may need three kinds of testing centres: 1) Existing PUC centres for vehicles without OBD 2) OBD testing centres for vehicles equipped with OBD, and 3) I&C centres with loaded mode-testing facility for vehicles failing the OBD tests.

This number of OBD-fitted vehicles will gradually grow requiring more centres of Type 2 and 3, and the number of Type 1 centres will gradually be reduced.