ENVIRONMENTAL POLLUTION AND HEALTH HAZARDS
DR. S. M .ALAM
Sep 24 - 30, 2007
Pollution is the addition to the environment of any substance or energy form (e.g. heat, sound) at a rate that results in higher than natural concentrations of that substance or energy form. The high rates of urbanization, industrialization, heavy transportation and deforestation have produced tremendous environmental problems around the globe in air, water and soil media. Any undesirable change in physiochemical or biological characteristics of our air, land and water will severely affect human life. Among the various types of pollution water pollution by waste discharge through various types of industries located around the big cities of a country is the main cause of deteriorating aquatic and agro ecosystems. Waste products of different industries pass through the drains, which often meet together at a certain place to form a big drain. These waste-water products ultimately fall into river water such river waiter is used for irrigation of crops, vegetables, etc. After using these vegetables/crops for eating affects the biological systems of our daily life. Environmental pollution has become a worldwide problem as it may adversely affect human health. This problem has been created by man himself as a result of indiscriminate release of harmful substances and toxic heavy metals into the environment from various socio-economic development activities such as industrial, agricultural, which may adversely affect the quality of air, water and food resources, these toxic chemicals may find their way to living organisms and human body through food chain and may induce various metabolic disorders.
The most important pollutants, which have greatly threatened to affect the quality of environment and ultimately our daily life are: a) Corrosive and toxic gases, cyclic and fluorinated hydrocarbons present in atmospheric air; b) agric-chemical, industrial and other chemicals; c) heavy metals, industrial and municipal wastes; d) radioactive substances and radiations; e) agricultural insecticide/pesticides.
Organic chemicals, especially the pesticides and detergents pose a serious threat to human health as these have been introduced into the environment during the last few decades and to which mankind has no previous exposure. Further, most of these chemicals do not degrade easily and progressively accumulate in the environment from there they in their way to the human body through the food chain. The annual consumption of various pesticides in Pakistan has increased from 906 m. ton in 1981 to more than 1200 m. ton in 1996. Commonly used pesticides are aldrin, endrin, dieldrin, endosulphan, chlordane, malathion, parathion, phorate, durban, diazinon, benomyl, aldicarb, aminocarb, chlopyrifos, carboryl, carbofuron, schardan, phosphomidan, aldicarb, propoxur, heptachlor, etc.
Particulate matter is an important source of pollutants, which is generated by many ways inside the building such as building and furnishing materials, office equipment and in and out movement of people. Airborne particulates may contain organic compounds, traces of metals, nitrates, sulphates, etc., which when inhaled may affect human health. The health effects of particulates depend upon the size, shape, density and reactivity of particles as well as on the respiration rate and quantity of intake. Air particles with a nominal aerodynamic diameter of 10 micrometer (urn) or less the ones, which penetrate into the respiratory system. Equipment used in the office also affects the quality of indoor air. Photocopying machines, fax machines, computer workstations, laser printers, adhesive tapes, glove correction fluids and marker pens are sources of volatile organic compounds, ozones and particulates.
After the nuclear weapon test, a large number of pollutants such as carbon monoxide, hydrocarbon, nitrogen oxides, sulphur oxides, heavy metals, acids, and variety of other toxic chemicals could be released in the atmosphere. They will affect the environment and deplete the ozone layer. World agriculture and major ecosystems such as forests, grass lands and marine system would be severely disturbed, which in turn, would affect their plants and animals. There are herbicides, acaricides and fungicides, which also affect the environment.
The Asian Development Bank has identified five key Pakistani industries i.e. textiles, leather, sport goods, surgical instruments and carpets which are extremely increasing pollution in the environment. Among these , leather and textile industries are major source of industrial waste water that is polluting rivers and lakes causing environmental problems in major cities of † Pakistan. The resulting impact on human health and environment has been severe. It refers to Pakistan Human Rights Commission Reports in 1998 which quantified loss to Pakistan economy by the environmental degradation at $ 1.65 billion. The loss is in addition to the impact of environmental degradation on health and lives. Cloth production , the ADB study points out † the require uses of a large number of detergents, dyes, acids, soda , salts enzymes which lead to a large amount of wastewater . In leather tanning, a large amount of chemicals such ad sodium chloride, ammonium sulphate, pigments and dyes are used. If not treated, waste-ware from both cloth manufacturing and leather tanning has serious consequences from environment and human health For humans. It is carcinogenic and allergy inducing and for environment, effluents pose a threat to inland and coastal fisheries which seepage into water table and introduces toxic chemicals into soil and food chain
In Pakistan, the industrialized areas of Karachi, Lahore, Faisalabad, Peshawar, Multan, Hyderabad etc. Under these circumstances in the severely- affected areas , the vegetation have been totally wiped out from the growing areas. There is a report that of air pollutants in Karachi, Rawalpindi and Lahore was 6.4 times higher than the World Health Organization(WHO) guidelines and 3.8 times higher than Japanese standards in recent years. The Jang Development Reporting Cell during the period 1994-2003 with 10 years, the average rain fall recorded is 101 mm to 1278 mm annually, also showing in Lahore as 681mm, Peshawar 517 mm , Quetta 206 mm and Karachi 129 mm.
Around 6,513 tons of garbage is generated in Karachi every day, out of which 5,257 tons is lifted and remaining is left unanswered. In a city of over 14 million, this is a major contributor to the filth and disgust that hangs over the port city. There are the three types of garbage, municipal waste, hospital waste are industrial waste. Karachi is known for dust allergy as I is everywhere in and out polluted with dust particles and vehicular smoke that also contain carbon dioxide and sulphur. Exposure to these elements are harmful. In addition to industrial pollution, Karachi atmosphere is affected by motor vehicles plying on the city roads. An average of ten vehicles come on the road after every one hour on road in Karachi. According to one report , the pollution caused by industrial emissions and automobile exhaust can cause asthma. In large cities that have air pollution problems, the number of emergency departments suffering from asthma attacks escalates when air quality is very poor. Carbon monoxide (CO) is produced when fuels such as gasoline are burned. Because it is colorless, tasteless, odorless and non irritating, it can affect the exposed person without any warning. It produces weakness and confusion, depriving the person of the ability to seek safety.
Atmospheric air pollution also causes the appearance and incidence of chromic bronchitis, optic irritation and lung carcinoma among urban population. The release of carbon dioxide (CO2) and carbon monoxide (CO) in the atmosphere affects the central nervous system even at low concentration. Both sulphur dioxide (SO2) and nitrogen dioxide( NO2) when inhaled irritate the respiratory system. The SO2 which causes formation of acidic condition in the atmosphere which causes damages to crops and forest, erosion of buildings and structures. During the last century an increase of 12 per cent times of CO2 ,was recorded which cause the global warming. And 50 per cent of global warming are caused by four countries i.e. US, China, Japan and India and at global level these countries generate about 47 per cent of CO2. The population of US is 4.6 per cent of world population and this country produces 25 per cent of CO2. Second is China with 12.5 per cent of world population and creates 12.5 per cent of CO2. Japan and India create 5.1 and 4.8 per cent of CO2 and their share in population growth is 2.1 and 16.9 per cent It is estimated that annually several million ton of these pollutants are emitted by photochemical plants, smelting processes, iron and steel mills, pulp and paper mills, coal cleaning and coke production, cement plaints glass manufacturing etc. petrochemical and paper mills 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 (Hg, cadmium, lead, nickle, chromium, cobalt, selenium, antimony, arsenic, Stennous, bromine, bismuth, titinium, etc.) accumulate in various organs such as live, heart, lung and brain and cause various disorders in the body. These metals cause hepatitis, colitis, tachycardia, anemia, insomnia, dizziness, hallucination, ostomalicia, 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.
Prolonged exposure to low levels of Hg produces symptoms of nervous disorder and myocardial necrosis and higher dose may damage liver and brain tissues. Cadmium (Cd) induces lipid deposition in arteries of heart and kidneys and produces atherosclerosis and hypertension. Excess intake of arsenic (As) causes myocardial necrosis whereas higher amount of Br damages heart tissues. Higher amount of Selenium (Se) creates problem such as depression, dermatitis, gas bio-intestinal disorder. Three elements namely mercury, Cadmium and lead are highly toxic and constitute a serious hazard to man and other living organisms.