The news might be a pleasant surprise to the people living in capital’s polluted environment, but there has been some improvement in Kathmandu valley’s air quality in the last two years. According to data of monitoring stations located in six places of the valley, air pollution in 2004 was 6 percent less than previous year. Although 6 percent decrease in the air pollution is not adequate where air pollution level is already higher than national as well as international standards in urban centers, this improvement in the valley’s environment is some relief to the Kathmanduites who are breathing polluted air for last few years.
Concentration of PM10 is a major concern for Kathmandu’s air. PM10, which is generated mainly by burning fossil fuels, can cause many respiratory disorders including asthma as it can easily reach human lungs during respiration and many harmful chemicals attach to these particles.
PM10 concentration in Putalisadak, one of the busy streets of Kathmandu, was found out to be 211 µg/m3 in 2003 which is almost double than national ambient air quality standard and about four times higher than European and United States’ standard. But in 2004, PM10 concentration was found decreased by four percent in Putalisadak thus averaging to 202 µg/m3.
Furthermore, a considerable improvement on air quality was recorded in Bhaktapur than busy urban centers of Kathmandu. In comparison with last year, PM10 concentration was found 15 percent lower in 2004 at Bhaktapur.
Why there has been improvement on air quality?
It is important to look at the recent developments on the policies and relative air quality monitoring data during the last two years to find out the cause of this improvement. Statistics have revealed that improvement in air quality in Bhaktapur is witnessed during the winter season, when air quality level is higher among other seasons. During four months; Mangsir, Paush, Magh and Falgun (mid November – mid March), PM10 level at Bhaktapur has been found 20 percent less in 2060 BS (mid April 2003- mid April 2004) than 2059 BS (2002/2003) and further in the year 2061 BS (2004/2005) during the same period, PM10 level was found to be decreased by 24 percent in comparison with 2060 BS (2003/2004). However, for the same period in these two years, PM10 level at Putalisadak has been found decreased by only 5 percent (detail on graph 1).
This significant reduction in the PM10 concentration in Bhaktapur suggests that the cause of reduction is around Bhaktapur area. For the last two years, one of the visible change around Bhaktapur area is shifting of old polluting brick making technology, locally known as Bull’s Trench Kilns (BTKs), towards cleaner ones. Although brick kilns are also found around Thankot and Kirtipur in Kathmandu district, most of them are situated in south-eastern part of the Lalitpur and Bhaktapur district. As during the winter season, brick kilns start their operation and also during the same time thermal inversion is prominent in Kathmandu valley, these brick kilns are more responsible towards the elevated air pollution level during this season.
Due to the high pressure from the local residents living around brick kilns and environmental organizations working for clean air, His Majesty’s Government has stopped registration of new BTK in 2060 BS (2003/2004) and also ordered the existing BTK owners to switch towards cleaner technology in the year 2061 BS (2004/2005). Some of the donor agencies provided technical assistance and some enthusiastic entrepreneurs were involved in the demonstration phase of new brick making technologies. Fixed chimney and Vertical Shaft Brick Kilns are the alternative technologies currently in practice. As these technologies reduced the fuel consumption as well as emission, it benefited everyone, from entrepreneurs to local people. Local people’s activism, government’s decision recognizing the voice of local sufferers, assistance from donor agencies and entrepreneurs’ willingness to investment on cleaner technologies has been paid off by some relief to the Kathmanduites in regards to the improved air quality. This has set an example that it is possible to improve Kathmandu’s environment if we could work together. Besides the brick kilns, credits could also be given to the government’s decision to ban two-stroke three wheelers and some old vehicles from Kathmandu.
It is obvious that this small improvement in the air quality has some positive results on reducing respiratory cases although not upto the desired level. Previous records of the respiratory disease patients in the hospitals of Kathmandu valley have shown an increased trend. During the four year period, from 2053 BS (1996/1997) to 2057 BS (2000/2001), respiratory patients were found increased by double. Although currently we do not have any statistics to verify the reduced respiratory disease cases, international studies and models developed by World Health Organization could help to predict the change. With the reduction in 6 percent in ambient concentration of PM10 during 2004 as compared to 2003, this improvement has avoided 200 cases of hospital admissions and 12000 cases of bronchitis in children. Furthermore, this could have also reduced the premature mortality by 0.64 percent.
Although this improvement on air quality which resulted in positive impact on health of Kathmanduites is appreciable, it is not sufficient yet. Now vehicle emission and resuspension from road are remained the major contributors to the air pollution. Furthermore, in order to minimize emission from brick kilns, regular monitoring of these industries and use of high grade coal (fuel) is essential. Last two year’s experiences have shown that if government can take up some bold steps and get support from local people as well as entrepreneurs, it is possible to reduce the air pollution level to the safe limit. In any way, we do not have any other option left but to reduce the level of air pollution of Kathmandu valley with everyone’s effort.
air quality, Kathmandu | 
