Bhushan Tuladhar

A recent study done by Clean Energy Nepal (CEN) and Environment and Public Health Organization (ENPHO) for Kathmandu Electric Vehicle Alliance (KEVA) has shown that Kathmandu’s air pollution is having serious impacts on the health of the valley’s residents and it is hurting the economy as a whole. Some of the major findings of this study were:

1. The concentration of particulate matter less than 10 micron (PM10) in Kathmandu’s air is very high, especially during the dry winter months. During the dry season, the PM10 level along busy roads such as Putali Sadak and Patan Hospital are above the national standard (120 micrograms per cubic meter) on 99 percent of the days. Even in residential areas like Thamel, the PM10 level exceeds the national standard in 90 percent of the days during the dry season. The monthly average PM10 recorded by four monitoring stations in Kathmandu Valley are shown in Figure 1.

2. The air quality in Kathmandu is deteriorating rapidly. Comparison of 24 hour PM10 monitoring data collected by ENPHO from Putali Sadak in 1992 to recent data collected from the same place by the Ministry of Population and Environment indicates that the PM10 concentration has tripled in the last 10 years.

3. The main reason for the rapid increase in pollution level is the increase in vehicle emission. An inventory of emission sources by MOPE indicates that vehicle exhaust has increased by more than 4 times in the eight years between 1993 and 2001. Over the past five years, the number of vehicles in the Valley has been increasing at a rate of about 17 percent per year, which is almost four times higher than the population growth rate in the valley. Although the new vehicles are of EURO I standard, there are many old vehicles that emit large amounts of pollution and even the new vehicles produce emission when they are not maintained properly.

4. The number of patients being admitted to Patan Hospital with Chronic Obstructive Pulmonary Disease (COPD) has doubled in the past five years. Similarly, the percentage of COPD patients as a percentage of the total medical patients being admitted to the hospital increased from 19 percent in 2052 to 27 percent in 2059. COPD is now the number one killer in Patan Hospital. Similar trends can be observed in the other major hospitals in the valley as well (see Figures 2 & 3).

Figure 2: Number of COPD Patients Admitted to Major Hospitals Over the Past 10 Years

Figure 2: Number of COPD Patients Admitted to Major Hospitals Over the Past 10 Years

Figure 3: COPD Patients as a Percentage of Total Medical Patients in Major Hospitals

Figure 3: COPD Patients as a Percentage of Total Medical Patients in Major Hospitals

5. The number of COPD patients in the hospitals reaches its peak in the dry winter months, which is also when air pollution in the valley is at its highest (see Figure 4).

Figure 4: COPD Patients Admitted to Major Hospitals in the Year 2059

Figure 4: COPD Patients Admitted to Major Hospitals in the Year 2059

6. Using dose-response functions, the study estimated that reducing PM2.5 level in Kathmandu Valley by just half (by 47.4 mg/m3) would reduce daily mortality by 7 percent and hospital admissions by 24 percent. Similarly, reduction of PM2.5 level in Kathmandu Municipality by half (by 63.4 mg/m3) will reduce mortality by approximately 10 percent and hospital admissions by 32 percent.

7. Similarly, reducing the annual average PM10 level in Kathmandu to international standards (50 mg/m3) will avoid over 2000 hospital admissions, over 40,000 emergency room visits, over 135,000 cases of acute bronchitis in children, over 4,000 cases of chronic bronchitis and half a million asthma attacks. Overall this means over 5 million restricted activity days and 32 million days with respiratory symptoms will be avoided. Currently the annual average PM10 level in Kathmandu is estimated to be 148 µg/m3.

8. A World Bank study has estimated the total cost of the health impacts of PM10 in Kathmandu in 1990 to be approximately Rs. 210 million. The study also found that reduction of vehicle exhaust emission is the most effective measure to reduce health damage. The study estimated that reduction of one kg of vehicle emission will result in saving Rs. 341 in terms of reduced health damage, whereas the saving due to reduction in domestic emission, which was next in the order of importance, was only Rs. 185.

9. Preliminary estimates indicate that reducing the annual average PM10 levels in Kathmandu to international standards (50 mg/m3) will save approximately Rs. 30 million in just hospital admission costs. A previous study by World Bank showed that hospital admission cost is only 0.02 percent of the total cost of health effects of air pollution. Therefore, it is safe to assume that billions of rupees can be saved by the lowering Kathmandu's PM10 levels to that of international standards.

10. Electric vehicles (EVs) can play a very important role in reducing emission loads in Kathmandu. Operating the existing trolley bus system can save approximately 3 tons of potentially carcinogenic particles from being released into Kathmandu’s air every year. Although zero-emission EVs are very suitable for Kathmandu and the government says it wants to promote EVs, in practice EVs are not getting sufficient support and their numbers are decreasing. Therefore a great opportunity to clean up Kathmandu’s air is not being fully utilized.

These findings clearly indicate the need for urgent action. Now that the Himal Cement Factory in Chovar, which used to be the main source of pollution in Kathmandu, is closed and cleaner brick kilns are starting to replace the old polluting kilns, vehicles are the main sources of air pollution and emphasis should be placed in controlling vehicle emission. As fine particles are the main problem in Kathmandu’s air, any future program to control Kathmandu’s air should focus on reducing concentration of fine particles. This means that diesel vehicles, one of the main sources of fine particles, need to be discouraged. Similarly, the rapid growth in the number of private vehicles needs to be controlled and “gross polluters” need to be taken off the road.

As Kathmandu is very suitable for the use of electric vehicles, these zero-emission vehicles should be promoted. An effective public transportation system based on EVs is the best alternative for polluting diesel vehicles and private vehicles in Kathmandu.

The government has taken a few steps to control Kathmandu’s air pollution but these have been ad-hoc decisions and Kathmandu’s rising levels of pollution clearly indicates that a lot more needs to be done. Overall, the government needs to make a serious commitment to improve Kathmandu’s air by drawing up a comprehensive action plan with the involvement of all stakeholders and then take bold steps to implement the plan.

International Evidence on Health Effects of Air Pollution Many international studies have shown that there are serious health risks associated with air pollution. According to the World Health Organization (WHO), air pollution is responsible for increases in out-patient visits due to respiratory and cardiovascular diseases, hospital admissions and mortality. WHO estimates that globally about 3 million people die each year due to air pollution out of which 800,000 premature deaths result from out door air pollution. Internationally, experts, as well as WHO, have recognized that fine particles are the most dangerous air pollutants as they can enter deep into the human body and they are often coated with toxic substances. WHO says there isn’t a safe limit for the concentration of PM10 (particle matter less than 10 microns) or PM2.5 (particle matter less than 2.5 microns) in the air as even at low levels they can cause harm to human health. The main source of fine particles is combustion of fossil fuel, such as vehicle emission. Diesel exhaust is especially deadly because diesel engines emit a large number of particles and more than 90 percent of these particles are less than 1 micron, which means that most of the particles go straight into the lungs. Scientists have also discovered the most dangerous carcinogen found till now in diesel exhaust. As the most common route for pollutants to enter the human body is by inhalation, the most common effect of air pollution is damage to the respiratory system. Exposure to air pollutants, can overload or break down natural defense mechanisms in the body, causing or contributing to respiratory diseases such as lung cancer, asthma, chronic bronchitis and emphysema. Air pollution can also have adverse impacts on other important systems such as cardiovascular system and central nervous system. A recent study indicates that a mere 10 mg/m3 increase in PM2.5 can increase the risk of lung cancer by 8 percent, cardiopulmonary deaths by 6 percent and all deaths by 4 percent. Children, the elderly, and people with lung and heart diseases are especially vulnerable to health effects of air pollution.

You can download the complete report from CEN’s web site (www.cen.org.np)