A World Bank report presented at an environmental meeting in Manila last week that named Kathmandu as the most polluted city in Asia has been flayed by air quality experts in Nepal. The report that went out internationally on the wire services last week lists New Delhi and China's Chongqing as second and third.

But Nepali environment experts, including those involved in air quality monitoring, say the report is unprofessional and has distorted the real picture. A World Bank consultant appears to have taken raw data of three-hour averages during rush hour from Kathmandu's worst-polluted streets and compared it to annual averages of other cities. That survey of Kathmandu air was carried out by the ESPS project in Kathmandu to determine the location of its monitoring meters, and measured the worst areas of Kathmandu during the most-polluted peak hours during winter.

The World Bank report cited Kathmandu's PM10 concentration (particles smaller than 10 microns per cubic metre) at more than 500, while the actual annual average is about 150. The World Bank report compared the worst pollution in Kathmandu to average levels for other cities. "This has done incalculable harm to Kathmandu's image," said air quality researcher, Toran Sharma at Aja ko Kura discussion program on Radio Sagarmatha on Tuesday. "Sure, Kathmandu has a pollution problem but you can't extrapolate data from non-standardised measurements." Kathmandu Valley ambient air pollution is now being measured by six monitoring stations and is posted on the Ministry of Population and Environment website (www.mope.gov.np) and weekly averages are carried in this newspaper (page 14).

The World Bank cited the case of Bangkok, where the visibility at the city's airport improved from about five km in 1996 to nine km in 2000. And, in Bangladesh's capital Dhaka, the phase-out of two-stroke engines on motorcycle taxis has slashed concentrations of fine airborne particulate matter by 41 percent.