Control Polution

Ministry of Environment has established an air quality monitoring system in Kathmandu valley consisting of six monitoring stations in Putali Sadak, Patan Hospital, Thamel, Bhaktapur, Kirtipur and Matsyagaon. These monitoring stations automatically collect 24-hour samples of air and the samples are analyzed for PM10. The data being generated from the six monitoring stations in Kathmandu gives a fairly good picture of the current status of air quality in the valley. Analysis of past data available from those monitoring stations revealed that Putali Sadak is the most polluted station followed by Patan Hospital, Thamel, Bhaktapur, Kirtipur and Matsyagaon. The seasonal variation in air pollution is especially high in Bhaktapur. This is mainly due to that most of the valley''s brick kilns are located around Bhaktapur and they start operating in November / December. In the mean time, wind in Kathmandu flows east towards Bhaktapur, carrying with it a significant amount of particles from Kathmandu. Due to the brick kilns and the westerly winds from Kathmandu, the air quality in Bhaktapur gets very much deteriorated in the winter season.

Reduction of vehicle exhaust emission is the most effective measure to improve air quality of the valley. Electric vehicles can play an important role in reducing emission loads in Kathmandu. Operating the existing trolley bus system could save approximately three tons of potentially carcinogenic particles from being released into Kathmandu''s air every year. As diesel exhaust is very hazardous for human health and it is the main source of fine particles, diesel vehicles should be avoided to the extent possible. Government should introduce economic tools, such as fuel tax, to discourage the use of diesel vehicles. Introduction of environment-friendly brick kilns can also significantly reduce the amount of pollutants in dry winter season. Public awareness campaigns are required to inform the people about the hazards of air pollution and what they can do to avoid or minimize air pollution.

A wide range of interventions are also available to reduce indoor air pollution, for instance, changes in energy technology, such as, switching from bio-mass fuels to cleaner fuels like kerosene, liquid petroleum gas, biogas, solar energy; improving the design and construction of locally made traditional stoves by the use of chimney, fume hoods; and changes in the living environment such as, improving the state of kitchen ventilation and raising awareness among the local people about the seriousness of the kitchen air pollution and building up participatory approach in the efforts made to reduce indoor air pollution.

Electricity as a source of cooking fuel may not be a good option considering its unavailability and cost factors. Good quality housing is a key element for healthy living. Poor housing can lead to many health problems, and is associated with various infectious diseases, stress and depression. Followings are the recommendations for the improvement of housing as well as indoor air quality in our settings: The concept of kitchen as an independent unit of the house is not in existence in Nepal. The separate unit for kitchen with the standard dimension based on fuel use should be recommended in practice. The awareness on health effects of indoor air pollution is lacking. So awareness-raising activities on effect of indoor air pollution on human health must be promoted. Use of environment friendly fuel must be promoted and considered as the best alternative for reducing indoor air pollution in houses.

Adequate home ventilation is important. Ventilation may be improved by constructing houses with sufficient number of windows particularly in cooking areas. Houses can be constructed using bricks with holes drilled through them (air bricks), which allows fresh air to circulate within the house. Ventilation in kitchen and other rooms can also be improved by incorporating mechanical devices like exhaust fans.

Health problems due to air pollution

The most common route for pollutants to enter the human body is by inhalation. So the most common effect of air pollution is development of respiratory diseases. Air pollution can also have adverse impacts on other important systems such as cardiovascular system and central nervous system. Studies have shown that children, elderly and people with lung and heart diseases are more vulnerable to the health effects of air pollution. An analysis of hospital records from three major hospitals in Kathmandu indicates that the number of COPD patients admitted to hospitals has increased significantly in the last ten years. Hospital records indicate that the number of COPD patients is highest in the dry winter months when air pollution in Kathmandu is at its highest peak.

World Health Organization (WHO) estimates that approximately 3 million people die each year due to air pollution in the world (World Bank 2003, ''Health Impacts of Outdoor Air Pollution''. South Asia Urban Air Quality Management Briefing, paper No. 11). According to the WHO, air pollution is responsible for increases in outpatient visits due to respiratory and cardiovascular diseases, hospital admissions and mortality.

Exposure from bio-mass smoke is estimated to cause a global death toll of 2.5 million every year equivalent to 4 to 5 % of total global deaths. In fact, the emerging data from recent studies indicate that risk-wise, it ranks only below malnutrition and poor quality of water / sanitation. In Nepal, total death from pneumonia alone is reported to be 4429 during the last 12 months preceding 2001 census (4.14 % of the total deaths). Similarly, the total deaths from asthma / bronchitis are reported to be 7170 (6.71% of the total deaths). According to Nepal Demography and Health survey, 2001, the prevalence of Acute Respiratory Infection for children below 5 years old is found to be 23 %. The below 5 years population is 12.1 % of the total population. Health hazards of housewives have been traditionally underestimated in the developing countries. . It is considered as a social responsibility of the women. The work of housewives can be categorised as hazardous occupation as they might be exposed to volatile organic compounds and polycyclic aromatic hydrocarbons everyday. There are evidences that indoor air pollution may increase the risk of respiratory tract infections and lung cancer among housewives.

Polution

Industrialisation and poverty are two major contributors leading to two different issues of air pollution; outdoor air pollution and indoor air pollution respectively. Basically, developed countries are concerned about outdoor air pollution, as; indoor air pollution is not a major issue in their context. Developing countries like Nepal are at double jeopardy; as the problem of outdoor as well as indoor air pollution is growing fast, and those pollutions are interchangeable.

Rapid progress in industrialization and mechanization has resulted in unlimited exploitation of natural resources, and in the absence of air pollution control mechanism, it has resulted in serious outdoor air pollution problems in Nepal. In our country, outdoor air pollution is a problem in the major cities like Kathmandu valley. The main sources of air pollution in Kathmandu are industries and vehicles. Other minor sources are domestic cooking fuels, refuse burning and resuspended dust particles. A study done by the World Bank in 1993 estimated that the contribution of vehicle exhaust to Total Suspended Particulate was only 3.5 percent compared to contribution of Himal Cement Factory (36%), brick kilns (31%) and domestic fuel combustion (14%). However, the situation in Kathmandu is quite different now. Himal Cement Factory along with other different industries has closed for different reasons and many people use less polluting cooking fuels like kerosene and LPG instead of biomass. But in the mean time, the number of vehicles in the valley has increased threefold. The emission from the vehicles has therefore probably increased significantly, while emission from other sources has decreased over the past 10 years. As a result, vehicle is now the number one source of pollution in Kathmandu. The main reason for the high level of vehicular emission is the large number of poorly maintained vehicles on congested streets, poor quality fuels and lubricants, weaknesses in the emission inspection & maintenance system and a poorly managed transportation system. Vehicles are the main sources of air pollution in Kathmandu as the places with heavy traffic (Putali Sadak and Patan Hospital) are the most polluted and the pollution levels drop significantly on weekends and during ''bandhs'' or strikes when there are fewer vehicles on the road.

Whereas, the major source of indoor air pollution in Nepal is biomass fuel. About 50 % of the world''s population is estimated to use solid bio-fuels like animal dung, crop residues, wood and coal for cooking daily meals and heating homes. The census 2001 report In Nepal shows that 80 % of households depend upon solid bio-fuels for domestic uses. is considered to be a significant source of public health hazard, particularly to the poor and vulnerable women and children.

Interrelationship between population and environment

The growing realization of environmental concerns culminated in the establishment of world commission on Environment and Development by the UNs General Assembly in 1983. The commission headed by brundtland submitled “our common future” in 1987. This report was a turning point in the history of human endeavor for safeguarding the environment. The commission has focused the attention among others, towards the rapid growth of population in many parts of the world the population is growing at rates that cannot be sustained by available environmental resources and pleaded for achieving sustainable development as the objective for human civilization.

The global warning, depletion of ozone layer and loss of bio-diversity are some of the immediate threats to environment. The average global temperature during the 1980s exceeded that of any other decade since reliable temperature recording began a century ago and 1990 was the warmest year on record. The elevated concentration of greenhouse gases is responsible for rise in temperature. This could lead to complex climatic changes including the rise in sea level. The available information shows that the concentration of some of greenhouse gases such as carbon dioxide: methane and Nitrous oxide have considerably increased since the beginning of industrial revolution carbon dioxide is the most important greenhouse gas which contributes 60-65 percent in total heat trapping followed by methane. All of the biotic and a biotic factors that act on an organism, population, or ecological community and influence its survival and development. Biotic factor include the organisms themselves, their food, and their interactions. A biotic factors include such items as sunlight, soil, air, water, climate, and pollution. Organisms respond to change in their environment by evolutionary adaptations in form and behavior. Living beings needed different type of resources for their growth and development. All the resources around human beings are the necessary parts of environment. Soil, forest, water, wildlife etc. natural environment is of crucial importance for social and economic life. We use the living world as:

1. A resource for food supply
2. An energy source
3.  A source for recreation
4.  A major source of medicines
5.  Natural resources for industrial products

Mean Summer Temperature

Summer remains hot and moist in Nepal in general. But the generalization of climatic condition is too difficult. Variation can be noticed in places within the same altitude and latitude. This variation is resulted by the physical diversities of the country. Like the winter season, the temperature zones in summer also run in east west direction parallel to the topographic features. The temperature in May, June and July remains the highest throughout the country. In summer, southern Tarai belt experiences hot wether condition with 27 to 30 degree temperature. Western Tarai experiences even higher temperature than the average of Tarai and sometimes ‘hot wave’ also take place.

The Hill region experiences 20 to 24 degree temperature. However, inner Tarai, fiver valleys and basins experience 20 to 27 degree temperature on an average. The temperature of Mountain region remains below 6 degree in general. But the temperature of higher altitude above 5000m and snow covered areas remain below zero degree.

Mean Winter Temperature (January)

The winter temperature of northern Nepal goes below minus three degree Celsius while it remains at 15 to 20 degree in the southern part. It is quite cold in the Mountain region. The temperature of Tarai, Inner Tarai and Chaure ranges remain from 12 to 18 degree Celsius. Tarai experiences extreme cold in the mornings. The cold wave has sometimes damaged winter crops since last few years. Kathmandu Valley also experiences very cold temperature in winter and sometimes it goes down below zero degree. The temperature of the middle belt remains between 6 to 9 degree on an average. It is neither too cold nor too hot in this region. The average temperature of the northern part of the country is low while the winter average temperature in the south is high.

Mean Winter Relative Humidity

Relative humidity is the ratio of the amount of water vapour actually present in an air mall and the maximum amount that the air mall could hold at that temperature. It is expressed in percentage. Saturated air has 100 percent relative humidity. For example, if air has the capacity of containing 16 gram of water vapour at a certain temperature but it contains only 12 grams at that temperatures, then its relative humidity comes to be 75 percent.

The relative humidity of southern Tarai is higher and it goes on decreasing towards higher altitudes. It is due to the presence of water vapour in the air. The mountain air is dry and less moist.