Smog towers for Delhi pollution are like paracetamol for dengue — won’t cure real disease

Supreme Court order to install smog towers in Delhi can be an experiment, but engineering solutions are just band-aid. The real problem is state capacity.

India Gate is eclipsed by smog in Delhi (representational image)| Photo: Suraj Singh Bisht | ThePrint

Earlier this week, when Delhi was dark and grey with smog, the Supreme Court asked the central and Delhi governments to look at the possibility of using smog towers, similar to the ones used in China to reduce pollution.

This is not the first time India is looking at our neighbours for emergency solutions — ‘odd-even’ was also something we learnt from China.

Taking emergency measures and not relying completely on long term solutions is a fair strategy. However, emergency measures have to be effective to justify their cost.

The case against smog towers

First, we have little or no evidence that any of the emergency measures practised in China have any impact. Data from China is scarce and transparency of public policy is an issue.

Second, the causes of air pollution in China are different from ours. When industrial pollutants are the main cause of pollution, as in the case of China, and are concentrated in industrial zones, smog towers in industrial hubs make a lot of sense. It is similar to water treatment plants where polluting industries discharge dirty water into rivers.

Putting a smog tower in an industrial zone may be a good solution for China. This may actually be a long-term solution and not just an emergency measure. Instead of each industry bearing the cost of pollution control, a cost-benefit analysis may show that it makes sense for each industry to pay a user charge for a common smog tower.

The case for smog towers

Perhaps not as an emergency measure, but as a pilot and an experiment, there is a case for smog towers in Delhi. China’s smog towers are based on ionisers; these are different from HEPA filters, which are being proposed for Delhi. Even if this version of the towers doesn’t meet our expectations, perhaps the next version will. We need to start somewhere, and perhaps, after a few iterations, we’ll find success. There is no reason why effective measures to treat critical situations shouldn’t be found.

Smog towers of the kind proposed may reduce pollution for about a square kilometre around them. The localised nature of their effectiveness also makes a case for them. Local governments have very few options to deal with air pollution. Delhi cannot solve the problem unless Punjab and Haryana change their policies.

If smog towers are effective, they could be an option for local governments. In the future, the decision regarding the installation of a smog tower could be left to a local government.

The core problem

Taking emergency measures like smog towers is like taking paracetamol during dengue. It treats the fever, which is a symptom, and not the disease itself. Until the disease is treated, there will be more symptoms. You may suffer from low platelet count or retina damage if you don’t go after dengue itself.

Similarly, even if we manage to reduce the solid particulate matter using smog towers, some other problem will emerge. Perhaps the levels of sulphur dioxide or ozone will exceed limits. That is something HEPA filters can’t reduce.

But this doesn’t mean treating symptoms isn’t important. Effective ways to deal with symptoms like solid particulate matter are something India should have in its ammunition.

There are deep societal problems too — people are bursting firecrackers even in emergency situations. The government resorts to distributing air pollution masks to school children, like Delhi CM Arvind Kejriwal did.

However, masks are not the solution — often, they do not even fit tightly, and children don’t use them all the time.

In pre-industrial days, Diwali was celebrated without choking others with poisonous gases. Campaigns for a green Diwali without crackers need be stepped up.

However, we cannot avoid dealing with the core problem.

The core problem is that of state capacity, not just in India, but also in China. Band-aid engineering solutions like smog towers only appear when we fail at science and social science. If India and China had succeeded in that, we would have done better source attribution. If both countries built state capacity, regulators could have prevented emissions from factories in the first place.

Both countries have only focused on engineering, which is useful in the short term. But there’s a risk that governments will show they are taking steps to solve the problem for political gains, while not solving the longer-term, more difficult institutional issues that are causing the problem. We should be cautious against taking such risks.

The author is an economist and a professor at the National Institute of Public Finance and Policy. Views are personal.