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BW Businessworld

And Its Peers

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ThE media have gone to town over Ludhiana; they have suddenly discovered that it is the world’s most polluted city. How did it reach this notoriety? How far has it sunk? What is the standard being used to condemn it? How significant is it? Someone who knows should be answering these questions. But in the area of environment, those who have studied it intensively are generally devout environmentalists; they are more loyal to their beliefs than to the search for truth. Someone should take an objective look at the issues.
I would like to start with Rachel Carson. She spent her working life in the Fish and Wildlife Service of the US government. Much of her early published work was about the sea. But she discovered that DDT, an insecticide which was invented in 1939 and spread rapidly because it was cheap and it killed a broad range of insects, was also killing birds, fish and crabs which accumulated DDT in their bodies from their diet of insects. So she wrote  Silent Spring in 1962. It was a modest, carefully written book. But it became an instant hit, partly because the highly lucrative pesticide industry launched attacks on her and the book. Two years later she died at the age of 64. Apart from being a meticulous biologist, she wrote beautifully. She is worth reading even now.
One result of the public consciousness that she had brought about was the creation of the Environment Protection Agency (EPA) by the United States in 1970. It introduced air quality standards in 1971 based on total suspended particles (TSP). The EPA’s interest in TSP levels arose from a long history of ailments caused by products of combustion in cold countries. Most of the particles that are inhaled with air are caught by nasal hairs or by mucus further inside, and ejected. But if they accumulate in the respiratory system, they can lead to discomfort and ailments.

The EPA’s National Ambient Air Quality Standards required that annual average TSP should not exceed 70 micrograms per cubic meter of air, and should be below 260 µg/m3 in every period of 24 hours during the year. In 1987, it replaced TSP by particulate matter. It would be tedious to enumerate the changes in standards since then, but after the last revision in 2012, it had standards for particulate matter weighing less than 2.5 as well as 10 micrograms, that is, PM2.5 as well as PM10.
Following the EPA’s lead, the World Health Organization’s Copenhagen office published standards for Europe in 1987. Today, it has global standards: 10 µg/m3 annual mean and 25 µg/m3 (maximum) 24-hour mean for PM2.5, and 20 µg/m3 annual mean and 50 µg/m3 (maximum) 24-hour mean for PM10. The second set of standards is exactly and arbitrarily twice the first. The WHO has just published annual mean PM10 for 1,099 cities, presumably because air testing facilities are concentrated in cities. It is notable how few the observations are on whose basis the pollution levels are calculated. In India, they are usually based on two and, at most, four stations in a city. It is implicitly assumed that there is not much spatial variation in pollution levels.
The figures clearly show a correlation between nearby cities. Ludhiana has PM10 of 251, Kanpur of 209, Delhi of 198 and Lucknow of 186. Pakistani cities also score high. Incidentally, Ludhiana does not have the highest level in the world. Quetta is at 251, and Ulan Bator is at 279. The highest level in the world, 372, is recorded in Ahwaz. Ahwaz is mentioned in the epigraph of Darius I, the Zoroastrian king who ruled Persia in the 5th century BC. It is the plural of Huz, Suz or Khuz, the name of the tribe that once inhabited it, and was the seat of Susiana, the Elamite empire which goes back to 3200 BC. Today, it is in the middle of a desert, and is one of the world’s hottest cities; its average monthly temperature exceeds 40 degrees centigrade from June to September.
This suggests the high PM10 levels in our part of Asia are not anthropogenic, but have something to do with our climate: in the arid tropics of Asia and Africa, there is more dust in the air, and has probably been for millennia. Indians, Persians and Arabs have lived in relatively dusty atmosphere for as long as they have existed. And the dust level is high because the climate is dry, plant cover is sparse, there is much dust on the ground and it rises into the atmosphere with periodic winds. India has created an expensive pollution control board in imitation of rich countries, but it can do nothing about air particulates. We have lived happily with high µg/m3 of PMx for millennia; let us continue as we are.
The author is Consultant Editor of Businessworld.


(This story was published in Businessworld Issue Dated 04-02-2013)