CONTROLLING THE EMISSION OF POLLUTANTS AT SOURCE

SHAMIM AHMED RIZVI
Sep 22 - 28, 2008

Environmental pollution which is often described as a 'silent killer' exists as an international phenomenon and is a direct consequence of rapid industrialization. It is rising throughout the world but its impact is more in the developing countries where preventive measures are not effective enough.

In Pakistan where preventive measures are almost non-existent the situation is much more serious especially in the big cities and industrial areas. According to the report air pollution in Karachi, Lahore, Rawalpindi, Hyderabad, Multan and Faisalabad was 6.4 times higher than the World Health Organization guidelines and 3.8 times higher than the Japanese standard. Under the circumstances in the severely affected areas vegetation has been totally wiped out from the growing areas. It is causing measured level of hazard to public health, but surprisingly nobody both in Government or civil society seems to be worried or concerned about it. It seems that environment has been the least priority in Pakistan. Last year Pakistan Environmental Protection Agency had issued a directive to the steel melting furnaces operating in the industrial sectors of Islamabad to install efficient devices for the purpose of controlling industrial pollution in the federal capital. It was a selective action of the agency for the federal capital but the whole situation in many other industrial cities was much worst.

Pollution comes from many sources. Apart from production and use of pesticides it comes from vehicle emission, tire fragments, road dust and power generation. Industrial combustion, smelting and other metal processing cause devastating effect on environment. Wood burning, soil pollens, mould and forest fires also add to air pollution.

The Asian Development Bank has identified five key industries in Pakistan in textile, leathers, sports goods, surgical instruments and carpets, which are increasing environmental pollution. Among these leather and textile industries are the major source of wastewater that is polluting rivers and lakes causing environmental problems in major cities and resulting in serious impact on human heath.

Production of cloth, the ADB study points out, requires a large number of detergents, dye, acids, soda, salts enzymes which lead to a large amount of waste water. In leather tanning, a large quantity of chemicals such as sodium chloride, ammonium soleplate, pigments and dyes are used. If not treated waste from both these industries have serious impact on environment and human health.

Big cities like Karachi, Lahore, Faisalabad, Multan and Hyderabad have an additional cause adding to the gravity of their environmental pollution in the form millions of tons industrial waste and garbage scattered on the roadside. The Municipal Administration has miserably failed to dispose off this waste, including hospital, industrial and chemical waste in a satisfactory way approved and recommended by health authorities.

The atmosphere of these big cities is being badly affected by ever rising number of vehicles including motorcycles, rickshaws, and trucks plying on the road round the clock adding to the population. According to estimates the number of such vehicles has multiplied by almost 3 times during the last decade. In Karachi alone the number has increased to about 2.5 million in 2007 from less than a million about 10 years back. According to a report, industrial emissions and automobile exhausts are the source of asthma. Carbon monoxide (CO) is produced when fuels such as gasoline is burned. As it is colorless, tasteless, odorless and non-irritating, it can affect the exposed person with out any warning.

There are also some indications that noise pollution can increase susceptibility to viral infections and toxic substances. Loud sounds can cause an arousal response in which a series of reactions occur in the body. Adrenalin is released into the blood stream; heart rate, blood pressure and respiration increase; gastrointestinal motility is inhabited; peripheral blood vessels contract and muscles become tense. In these studies noise has been related to the following diseases; headache, fatigue, insomnia irritability, neuroticism, tension, hypertension, hypotension, cardiac disease, lunacy, narcolepsy, ulcers and colitis.

Petrochemical and paper mills also release highly toxic elements in the atmosphere. Several industrial operations such as metallurgy, electroplating, manufacturing processes, mining, milling and commercial operations release traces of heavy metals into the environment from where these metals can enter human body through air, water and food chain. These metals (mercury, cadmium, lead, nickel, chromium, cobalt, selenium, antimony, arsenic, bromine, bismuth, titanium, etc.) accumulate in various organs such as liver, heart, lungs and brain and cause various disorders in the body. These metals cause hepatitis, colitis, tachycardia, anemia, insomnia, dizziness, hallucination, osteomalacia, etc. These metals being biologically non-degradable accumulate in the vital organs of human being such as brain, nervous system, kidney, liver, intestinal tract and lungs and adversely affect the biochemical processes.

Use of pesticides is increasing day by day by our farmers to protect their crops from pest attack and avoid crop loses. Crop losses are being controlled but in the process the number of pesticide toxicity cases is also increasing. It is also spreading air and atmospheric pollution to rural areas as well.

It is high time that authorities focus their attention to save our environment from further pollution. It is necessary to maintain a reasonably good air quality to protect human health and environment from adverse effects of pollutants. This can be achieved by controlling the emission of pollutants at source. For regular monitoring of pollution levels in the air expertise should be enhanced through training programmes and organization of seminars and symposium.