The causes and effects of PM10 in Kathmandu valley

Arya Joshi, Deeptishree Shrestha, Piyush Raj Aryal and Samagya Karki, MBA Students, Kathmandu University

Cough and cold, nose and throat irritation, wheezing are the most common health problems that the residents of Kathmandu valley are facing. One of the major reasons is air pollution. Air Pollution stands as a major cause of our deteriorating environment and health condition. Science and technological development has done wonders for the betterment of mankind. However, it has also added to different forms of pollution among which air pollution is most devastating.

Air pollution means the contamination of pure air through both organic and inorganic impurities. The agents causing air pollution are called Air Pollutants. Air pollutants consist of gaseous pollutants (carbon dioxide, nitrogen dioxide etc) and TSP (solid matters, dust particles and liquid droplets). Out of TSP (Total Suspended Particles) 55% consists of particulate matters that are less than 10 microns in diameter i.e. PM10. It is about one-tenth the breadth of human hair. Current data on TSP shows that Kathmandu Valley is being affected mostly by PM10. WHO guideline states that the concentration of PM10 should not exceed 70 microns per cubic meter in the surrounding atmosphere in 24 hours. But Kathmandu Valley registers between the ranges of 49 to 495 microns per cubic meter in 24 hours.

The main sources of PM10 in Kathmandu Valley are Vehicular Emission, Emission from Brick Kilns and Emission from Himal Cement Factory.

Vehicular emission: Vehicular emission is responsible for about 60% of particulate air pollution in Kathmandu valley. With the expansion of the roads, the number of vehicles has increased meritoriously and so has the consumption of fuel.

Total number of vehicles registered in Bagmati zone over the last six years

The above table shows clearly that the number of vehicles, especially two wheelers has has increased two fold since 1996. While a decade ago, the vehicles used to travel in the valley at the average speed of 25/30 km per hour. At present this has reduced to the average of 4/5 km per hour. It is obvious that the increase in the number of vehicles increases the traffic congestion but decreases the speed. With the decrease in the speed the vehicles remain in the roads for a longer time and more particulate matter is emitted in the environment.

Emission from Brick Kilns: Another factor contributing about 31% of TSP in the Valley is the emission from brick kilns. As a business with minimal investment and high-expected profit, brick kilns mushrooming in various parts of valley are being the major contributors to air pollution in the valley. There are around 125 registered and unregistered brick kilns operating in the Kathmandu Valley.. Most of the brick kilns use Bulls Trench technology for manufacturing bricks. Though this technology uses coal as the major fuel, tyres, saw dust and any inflammable matters are also used as alteranative cost offsetting fuels. This technology is inefficient and environment unfriendly and has been banned in many countries. However, this kind of technology caters about 87% of brick need in the valley. There are other more environmental technologies like Hoffmann (Chinese) and Vertical Shaft technology but these technologies are not much used for the purpose of brick manufacturing.

What further aggravates the matter is that most of these kilns are located in the southern parts of the valley and the prevailing southwest wind blows the dust particles back to the valley itself.

Emission from Himal Cement: Although Himal cement has been officially closed since 14th Jan 2002, l Himal cement had played the role of a major culprit for the air pollution in Kathmandu valley. It is believed that each day during it’s production it emanated 6 tonnes of dust everyday .As PM10 remains in the air for the span of 1 to 5 years, the hazardous particles emitted from the industry about five years ago still lingers in the air of valley. Because of the bowlike topography of Kathmandu valley, these particles get easily accumulated in the atmosphere and get trapped there.

Health effects of PM10

PM10 are present everywhere, but high concentration of particles causes a serious danger to human health. These particles are small enough to be inhaled into the deepest parts of the lungs. Particulate matter is especially harmful to people with lung disease such as asthma and chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema, and other heart diseases. When inhaled, these particles evade the respiratory system’s natural defenses and lodge deep in the lungs. Depending on the size, dust affects human respiration. The larger particles are inhaled into the upper respiratory tract and most are immediately exhaled. Smaller ones penetrate the larynx to enter the traecho-bronchial region and trigger infections. The smallest ones go deep into the lungs and can lead to asthma, lung disorders and even cancers. Exposure to particulate air pollution can trigger asthma attacks and cause wheezing, coughing, and respiratory irritation and even premature death in individuals with existing heart or lung diseases, especially the elderly with pre-existing respiratory or heart disease.

Impacts on Vegetation

Plants breathe and carry out photosynthesis through the leaves. Plants exposed to high concentration of PM10 have a layer of invisible dust particles on the leaf surface. Consequently it becomes difficult for the plants to breathe and carry out photosynthesis for their survival. The vegetation around the brick kilns and Himal Cement has been adversely affected, with reduced productivity and biomass of plants.

Recommendations

Even though the government has the Environment Conservation Act 2052 in force but the rules and regulations are not implemented well. The existing rules and regulations should not be limited to government blueprints, but they should be well complied and adhered to. For the past few years the number of vehicles have increased rapidly lessening their speed. Therefore, an initiative should be taken towards broadening, maintaining and reforming the existing roads and constructing new ones. The best way to lower the vehicular emission is to make the maximum use of environment friendly vehicles. Fuel quality should be regularly checked. Also the vehicles that are more than 20 years old should be banned as soon as possible.

Bulls Trench technology in brick kilns should be banned and more environment friendly technology like the Vertical Shaft and Hoffmann Technology be commonly practiced .In the words of Usha Sharma, environmentalist at IUCN,"It is true that industrialization is important for the economic development of a country but at the same time the basic concern of a country is its healthy citizens. Industries should be aware of their emissions and the government should make provision to introduce the compulsion of fitting the pollution controlling equipment for the industries."

We all have our share of responsibility in maintaining the environmental cleanliness. Conservation of healthy environment means protecting you and your future generation from a lot of dangerous diseases. We on our part as dutiful citizens of the country can contribute not only to the decrease of PM10 but that of air pollution as a whole by keeping vehicles in proper condition and not using adulterated fuel.

This article is the outcome of the research works conducted by Arya Joshi, Deeptishree Shrestha, Piyush Raj Aryal and Samagya Karki, who are the MBA students at the Kathmandu University, School of Management. This research work was sponsored by Kathmandu Metropolitan City Office.

Headline | 5 Question  | Editorial | 2nd Impression | International | Past