Air Pollution in Kathmandu

Introduction:
Air Pollution in Kathmandu
Air pollution is known as the unwanted physical, biological and chemical portions which degrade its standard quality. The main sources for the pollution are the air pollutants. In case of Kathmandu Valley when we look at down to the valley from aeroplane, it looks like the whole city is covered by dust particle. We can see how air pollution destroys the purity of air resulting degradation of the air quality in the valley which directly effects human being during resperition.

The main pollution in Kathmandu is vehicle pollution, because the roads are not properly managed and cleaned. In nepal pitched-roads are not in standard quality. New pitched-roads last hardly for two years. There are dust particles on the roads, and when old vehicles move on such road, the area is covered by dust particles and black gases. This is the main problems in the valley.

Balaju industrial area and Lalitpur industrial area are separated from the main city but it produces different types of toxic gases, lead and complex organic compound etc. during the course of production. It produces mixture of harmful gases like sulphur diooxide, canbon dioxide, nitrous oxide, etc.


Description in Brief

Air pollution is serious problem in kathmandu. It has exceeded the thershold values, and now it is in worst condition. So, in these days many people are facing respiration problem. Meteorological factors are also known to increase the air pollution level in Kathmandu Valley. There are linkages between meteorological processes and air pollution in the lower atmosphere of the Kathmandu Valley. Particulate matter with aerodynamic size less than 10 microns (PM10) and weather conditions (wind speed and direction, precipitation, and temperature) are the two factors for the pollution. Air pollution recorders are established in some junction of the valley and the recorded data are classified according to the United State Environmental protection Agency (USEPA) and Air Quality Index (AQI). Usually seasonal, weekly and daily variations of PM10 concentrations are to be analyzed. Although air pollution is caused by different vehicular and nonvehicular sources, particulate concentrations in Kathmandu Valley are influenced by meteorological factors. These factors are atmospheric stability, wind speed, wind direction. and precipitation.

The physial setting of Kathamndu also influences air pollution concentrations. Hence, it is found that the mountain-valley setting produces mountain valley circulations that influence air pollution transport in winter, and air pollution is carried out of Kathmandu valley during the day, while the mountain freeze causes pollution to return to the Valley at night. Since the variation in PM10 concentrations is influenced by different meteorological factors in addition to sources. People use masks to cover their noses and mouths when they are walking in the streets and in riding bikes. At present 4 million people are living in this crouded capital city, and the numbers of vehicals are also more than road capacity.

We have found two important factors to increase pollution. Usually air pollution raises up during day when temperatrure is increasing, and it gets down at nigh when the temperature is decreasing, and this circulation process is continued. So, the air pollution is countinuing to pose serious health threats. The average amount of total suspended particulate in the air of main commercial areas is greater than 1000 ppm (particle per million). It is too high than WHO standards value 150 to 230 ppm. Recorded benzene level is 23 to 67 ppm that is also more than WHO standards value 5 to 20 ppm. The concentrations of PM10 is 200 ppm and WHO standards only 70 ppm.









Posted by Chok Bahadur Gurung on 3:56 AM

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