Pollution
Sources and effects of pollution
Pollution of water (including surface, ground and sea water) and soil has become a serious problem in Sri Lanka. The main sources of water pollution are domestic, urban and municipal wastes (including both sewage and solid wastes), agro-chemicals (such as pesticides, fertilisers and herbicides), industrial effluents (including chemicals, detergents, heavy metals and oils), and marine and shipping wastes (including oil spills, chemicals and ballast water). Although the main source, and danger, of soil and water pollution comes from wastes and substances introduced by humans, there also exist natural conditions, which make certain sources of water unsuitable or potentially dangerous for human consumption. For example consumption over a long time of water with high naturally-occurring levels of calcium can give rise to kidney stones in susceptible individual. High levels of fluoride can cause discolouration of teeth and brittle bones.
Two major problems give rise to water and soil pollution: the improper disposal or treatment of wastes, and the use or generation of toxic or harmful chemicals. Many households and companies in Sri Lanka are not connected to a proper sewerage system, or the system they rely on does not treat their wastes effectively. Many industries make no effort to properly treat or dispose of their effluents, even though they are required to do so by law.
Water and soil pollution have very serious long-term impacts on human health and the environment. Human beings require water of good quality if they are to grow to their full potential and live a healthy life. Contaminated water is already directly responsible for a large proportion of the diseases in our country.
For these reasons, standards have been set for potable water (water which is suitable for humans to drink) and effluents (wastewaters which are discharged from industries and sewage treatment plants). In addition, various regulatory bodies ensure that agro chemicals are used in a manner which safeguards human health.
Air pollution is a broad term applied to any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere. This includes the air that we breathe, as well as the bigger layer of gases that surround the planet earth.
Air pollution causes many problems to both human and environmental health. Effects include increased respiratory diseases and difficulty in breathing. Plants and animals are also affected by air pollution. In addition, sulphur dioxide and nitrogen oxides may be converted into acids, which is deposited as acid rain. This can increase the acidity of the soil, and affect the chemical balance in lakes and streams. Acid rain also accelerates the weathering of buildings and carbonate rocks, and damages trees and forests at high elevations. Reductions in ozone levels in the earth’s stratosphere (the region of the atmosphere which extends from about 10 km from the earth’s surface up to 50 Km) will lead to higher levels of UVB rays reaching the earth’s surface, which in turn links to increased incidence of skin cancer and cataracts. It is also suspected that ozone depletion leads to damage to plants, and a reduction in plankton in the ocean. The problem of global climate change is linked to the accumulation of gases, including carbon dioxide and methane, in the atmosphere.
For these reasons, standards and guidelines have been set for Sri Lanka in relation to air pollution. These cover general (ambient) air quality, vehicle emissions, fuel standards, incinerators, and ozone-depleting substances. As a result of EFL ongoing case in the Supreme Court, mandatory vehicle emission testing has being introduced for all vehicles and new traffic plans have been established to ease congestion in and around the city of Colombo.
Sound is a form of energy that is detected when sound waves cause the eardrum to vibrate. The nervous system of human beings and certain animals then translate these vibrations into sounds of various qualities and intensities. The greater the energy that translates into movement of the eardrum, the louder the sound is perceived to be.
Noise is basically undesirable, harsh, loud, unpleasant or continuous sound. The impacts of noise pollution range from continuing stress, annoyance and disturbance, to severe physical effects such as nausea, headaches and even deafness. The known negative impacts of noise are illustrated by the fact that in many countries subjecting people to loud, recurrent noises is used by the police as a mechanism to disperse crowds and demonstrations, and is also used as a method of human torture.
Noise pollution comes mainly from human activities. Since most human activities generate sound and noise, “normal” or “tolerable” levels of noise need to be distinguished from what can be considered to be harmful noise pollution. As with any form of pollution, the people most affected by noise pollution are those who do not generate it. It is therefore necessary to ensure that noises from all sources are kept to a minimum, so that total noise is within acceptable limits and the least distress is caused to those who are not responsible for generating a particular noise. This is done by setting standards for particular activities in specific localities and by prohibiting certain activities in particular locations. For example, while the maximum permissible noise levels have been set for silent zones, it is illegal to toot a horn in a silent zone at any time and under any circumstance.
For these reasons, standards have been set in Sri Lanka for noise levels through the National Environmental (Noise Control) Regulations No. 1 of 1996.
For complete details on Water, Soil, Air and Noise pollution refer to Your Environmental Rights and Responsibilities: A handbook for Sri Lanka available at the EFL Library or at selected bookshops.
