When the air turns toxic

The ghost-like appearance of Beijing and many other Chinese cities as they became shrouded in a toxic smog with particulate levels 25 times higher than safe limits last week was a scary reminder of the fate awaiting countries that fail to take their air quality seriously. A fate that was graphically illustrated by a recent Beijing university study which estimated that the number of people dying prematurely as a result of air pollution in four of China's major cities was close to three times the number killed in traffic accidents.

While weather patterns may have played a part, much of the blame for the chronic air pollution must lie with unregulated industrial development and rapid urbanisation which has spawned an excess of motor vehicles, the proliferation of coal-fired power plants and a consequent increase in the number of people seeking medical treatment for bronchitis, asthma and other respiratory ailments. But these are not the only factors involved in producing dangerous levels of particulate matter and poor air quality.

Those living in the north of Thailand will have looked at the images of haze blanketing Beijing with a particular sense of foreboding because they know they will face a similar ordeal in the coming weeks as farmers burn off fields, leaves, rice straw, rubbish, grasses and other crop residue ahead of the next planting season. Blazes are also set by hunters to flush out wild animals.

It is an intolerable situation for those living in and visiting the North and hospitals are swamped with victims of the acrid smoke, mainly suffering from respiratory problems and eye inflammation.

Every year history repeats itself. Health and forestry officials promise a new campaign to convince landowners not to burn forests, rubbish or grass but this fails because it involves changing their traditional way of doing things. It is a practice used around the world as a quick and inexpensive way to clear the land for the next crop, returning valuable nutrients to the soil in the form of inorganic ash, and cleansing the land of weeds, pests and diseases. Acceptable alternatives to achieve similar results do exist and education coupled with a well thought-out incentive scheme would be more productive than levying fines that are rarely paid. But such programmes need to be implemented before the burn-offs begin.

While burn-offs are seasonal, Bangkok's unremittingly poor air quality is not. Nor is it about to improve. Instead, the Pollution Control Department has warned that it will deteriorate significantly due to a dramatic increase in the number of private cars in the city. The prediction is based on the department's 2011 survey of the level of benzene detected by four air quality measurement stations in the Din Daeng, Pathumwan, Wang Thonglang and Thon Buri areas. Benzene is a known carcinogen used as an additive in petroleum products. A follow-up survey has found that its level in the capital's air is still far above what it should be.

Yet there is a positive side to all this. Air quality in Bangkok is not quite as bad as it was in the years before leaded petrol was outlawed, the skytrain and subway brought on line and LPG and CNG adopted as taxi and bus fuels. Gasohol, while marketed as a "green" fuel, brought with it its own set of problems, but has since won acceptance. At least the filthy brown cloud, which during rush hours blotted out the sun, has turned light grey and the skies are blue again. But we still have a long way to go before we gain the moral right to criticise what China has done to its air. Let us at least hope that we can learn from Beijing's mistakes, as well as our own.