Ramesh Dahal

Researchers say that the bowl-shaped topography of the Kathmandu Valley does not permit air to outflow which has increased the vulnerability of air pollution. According to the World Health Organisation (WHO), air pollution is the contamination of indoor or outdoor air due to harmful particulates and chemicals. It is a mixture of various components such as airborne particulate matters like Ozone, Nitrogen Dioxide, Benzene, Carbon Monoxide, Sulfur Dioxide, and Carbon Dioxide. The content of these chemicals in the air affect human health.
As per a research conducted by Yale and Colombia Universities, Nepal is among the top five polluted cities of the world. Air quality in 2016 dropped to 27 points from 149 points which notify that the air quality of Nepal, especially in Kathmandu, is hazardous for human health as pollution level is above the WHO guideline. The air contains particulate matters of 2.5micrometer which is five times above the National Ambient Air Quality Standard.
The air of Kathmandu consists of particles of different sizes. Particulate matter of 10 micrometre comes from a damaged road, construction site, and farm. Particulate matter less than 2.5 micrometres in size comes from traffic emission and soil dust. Carbon monoxide comes from incomplete combustion of fossil fuel. In the car engine, nitrogen reacts with oxygen at high temperature to produce nitrogen monoxide. Sulfur dioxide is another harmful gas for human health.
Records show that the number of vehicles has been on the rise significantly in the Kathmandu Valley. A research conducted by Bhuvan Saud and Gobinda Paudel shows that the number of vehicles jumped to 7,79,822 in 2015 from 24,003 in 2000/2001. Todays’ data of vehicle registration in Kathmandu crossed 1.1 million which is beyond the capacity of the valley.
According to ICIMOD (2006), 38 per cent of the air pollution comes from vehicle emission, 18 per cent from the agricultural sector, and 11 per cent from brick kilns. The current scenario of air pollution is worse than ICIMOD’s data (2006).
Air pollution of the city is unacceptable to human health. Epidemiologists are worried that air pollution of Kathmandu is enough to increase the rate of human morbidity and mortality. A long-term exposure to the air results in a runny nose, cough, bronchitis, eye irritation, and asthma. The polluted air damages human health with a respiratory problem, heart disease, cancer, reproductive health, and birth defects.
The research conducted by Soud and Paudel forecasts that the premature annual deaths due to air pollution in Kathmandu will be above 24,000 by 2030 as compared to 9,944 in 2012. This shows that air pollution is a ‘silent killer’ but we are less aware of the chronic and infectious diseases resulted by it. The unmanaged traffic and particulate matters from the broken road and haphazard construction work in Kathmandu will increase the toll. However, the authorities concerned have not made adequate efforts to contain air pollution in the valley.
In order to protect human health from hazardous pollutants, the residents are advised to adopt an environment-friendly lifestyle. Practising sustainable mobility will cut down the emission. They can avoid burning the wastes. They may increase greenery at the yards. If they do not have sufficient spaces, they can increase greenery at the terrace. By terrace farming, they can get organic vegetables, enhances the beauty of their terrace. Through such efforts, they can capture the dust particles. The vehicle users need to keep their vehicles in good condition. They should turn off their vehicles even when they are in a short traffic jam. People are advised to avoid plastic shopping bags.
The government must have a strong willpower to control air pollution. In the short run, the government educates city residents to practise sustainable mobility. It should motivate the people to follow environment-friendly livelihoods. Then, it should implement the zero air pollution policy.
In the long run, the government needs to remove the most polluting vehicles from the city. A study should be conducted to implement the ‘carbon trade’ which is also called ‘carbon cap’ or ‘carbon permit’ among the industries. As per this this approach, the unsuccessful industries should be forced to buy carbon unit from the successful ones. Carbon trade is simply a financial incentive for reducing emissions. However, the loss or gain in terms of monetary value will motivate industries in lowering the emission. A carbon tax provision is another means of controlling air pollution but it is less suitable for developing countries like Nepal as it increases the market price of commodities.
Urban tree canopy is a way of capturing particulate materials and vehicle emission. It can help minimise urban heat island effect, too. The canopy beautifies the city and captures around 80 per cent of the carbon and dust particles.
Therefore, the most efficient and reliable approach to controlling emission is the promotion of renewable energy. Viable sources of renewable energy for Kathmandu include solar, wind, and hydropower. Greening public transportation by switching to renewable energy can reduce emissions to almost zero. However, promoting renewable energy needs huge investment and takes time. The government needs to implement immediate measures with the participation of the residents of Kathmandu to protect human health.
(Dahal is an environmental specialist. He can be reached at lyrist.rameshdahal@gmail.com.)