Asia is drowning in motorbike pollution

Posted: 15 February 2002

Asia is drowning. The exploding number of two and three-wheelers on Asia's streets promise to flood the continent with pollution. These vehicles may be the backbone of the commuting millions in Asia but they are also the greatest threat to public health.

Today they form nearly 70-80 per cent of the vehicular fleet of Asia and as population grows and the continent develops economically the numbers will only rise exponentially.

Unmasking the dragon

About 85 per cent of traffic on Hanoi’s streets consist of motorbikes. In Taiwan, one only needs to divide the country’s population by two to get the number of motorcycles. About 70 per cent of the vehicular fleet in India consists of two and three wheelers. China produces almost three times the number of vehicles as India.

Asia’s two-wheeler population rises steadily© CSE. Data provided by Japan Automobile Manufacturers Association Inc., October 10, 2001It’s a situation that is unique only to Asia in more ways than one. More than 90 per cent of the world’s two and three-wheelers are produced in Asia and the region boasts of some of the most polluted cities in the world. Perturbed by such trends, emission watchers warn, "Get ready for a public health catastrophe."

Scientists are finding new evidence about pollutants from these vehicles. "Two and three-wheelers constitute three-fourth of the Asian vehicular fleet. These emit up to 70 per cent of the total hydrocarbons, 40 per cent of the total carbon monoxide and a substantial part of the particulate pollution in the region," says Jitendra Shah, an environment engineer at the World Bank. © CSEData provided by Japan Automobile Manufacturers Association Inc., October 10, 2001. The fact that these vehicles emit particulates is new. But frightening in terms of public health. The problem is particularly difficult in the case of two-stroke technology, which makes up the majority of the fleet on road. Two-strokes have a problem because of their inefficient combustion which leads to deadly emissions in the form of unburnt hydrocarbons.

An estimate by Michael P. Walsh, a US-based expert on vehicle technology, shows that at some traffic intersections in Bangkok, motorcycles contribute more than 47 per cent of the total particulate load. Until now, there was little information about the particulate emissions - tiny pollutants which are inhaled deep into the lungs - and as a result nowhere in the world are particulates from two-wheelers even regulated.

For Delhi, the situation appears grim. If public transport shifts to compressed natural gas (CNG), two-wheelers will become the biggest polluters, estimates the Centre for Science and Environment (CSE), a Delhi-based non-governmental organisation. Futhermore, people using three-wheelers are the most vulnerable to exposure to particulate pollution.

A recent workshop discussing the emissions from two and three-wheelers reasserted that regulations to control particulate emissions were not on any country’s agenda. Walsh, participating in the workshop organised by the Asian Development Bank, Vietnam Register and the United States-Asia Environment Partnership at Hanoi, said, "Though we know that particles are hazardous, there is very little chemical analysis of particles from two-stroke engines." This is the challenge. "Asia will have to take the lead in conducting studies and formulating regulations to reverse the growing air pollution threat. Industry must use the precautionary principle to invest in cleaner technologies," adds Walsh.

Copyright © CSE Centre for Science and Environment.

A fuller version of this article, published in Down to Earth, Volume 10, Number 17, January 13, 2002, can be found at the Centre for Science and Environment website:

Quick solutions The most radical of options is to impose an outright ban on two-stroke engines and favour four-stroke technology. Nepal has done exactly that. "Indian exporters now sell four-stroke scooters which are also affordable," says Bhushan Tuladhar, executive director, Clean Energy Nepal. Taiwan too promises to stop production by 2004. "Taiwan Environment Protection Agency and two-wheeler manufacturers have an understanding to stop the production of two-stroke two-wheelers by January 2004." says, Jet P H Shu, deputy general director, Industry Technology Research Institute, Taiwan.

The other way out of the mess is to not impose a complete ban but put up stricter emission norms that push the technology out.

Thailand plans to do just that. "Most manufacturers are changing over to four-stroke motorcycles because some two-stroke motorcycles can’t clear the emission norms. By 2003 when tougher standards are in place, we’ll have only four-stroke motorcycles," says Janejob Suksod, chief of the automotive air pollution sub-division of the Thailand Pollution Control Department. But some experts assert that a complete ban is the only way out.

Copyright © CSE Centre for Science and Environment