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WH&T is POLLOT
Most people think of environmental conservation in terms of the prevention of pollution -- the control of discharge of unwanted, sometimes toxic wastes to the water, the air, or the land. This is only partially correct and reflects an urban bias; yet the importance of controlling pollution cannot be denied and is growing more urgent by the year.
Water pollution has three main sources: bacterial and organic liquids and solids from urban and rural domestic sewage; toxic metals, organics, acids, and other less-toxic but still polluting substances from industrial discharges; and chemical pollution in the form of pesticide and fertiliser nun-off from agricultural lands.
AH three can contaminate both surface and ground-water supplies of water and render them unfit for other uses such as fisheries and recreation, or expensive to treat for industrial and municipal water supply uses. The costs of treatment places a heavy burden on municipal authorities and industries that must rely on polluted sources.
Domestic and human waste water discharges
Solid and liquid excreta generated in human settlements along with kitchen and wash waste water are the major sources of water pollution in Pakistan and the cause of widespread waterborne diseases. The seriousness of the situation is clear form a World Health Organisation study: diseases-of a gastro-intestinal nature account for 35-30 per cent of the cases seen >*t public hospitals and dispensaries in Pakistan. Approximately 60 per cent of infant deaths are due to infectious and parasitic diseases, most of them water-borne. Losses to the national economy, not to mention the human suffering, caused by water-borne diseases are high. A study i India found that 73 million work days a year were lost through such disease. The cost in terms of medical treatment and lost production was reported to be on the order of US $600 million per year.
As indicated, the source of most water-borne diseases is human excrement. Pakistan generates 34.370 wet tonnes of excreta
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per day, 12.5 million tonnes per year. Karachi alone discharges approximately 300 million gallons per day* of sewage; Lahore, approximately 240 million gallons. The organic load discharged, measures in terms of biological oxygen demand, for all of Pakistan is 2,265 tonnes per day.
The breakdown by source is 26,370 tonnes excreta from rural areas a day and 8.000 tonnes from urban areas. An estimated
21,096 tonnes from the rural areas (80 per cent) is deposited in fields. An estimated 4,160 tonnes of the urban excreta (52 per cent) is disposed of into sewers, with the remainder being deposited on the roadside, into waterways, o incorporated in solid waste.
Major cities dispose of their largely untreated sewage into irrigation systems, where the waste water is reused, and into streams and rivers, without any consideration for the rivers' assimilative capacity. Consequently, not only does serious bacterial contamination result, threatening human health, but the organic load of the sewage seriously depletes the dissolved oxygen content of the receiving waters, causing un-aesthetic conditions and making them unfit for fish. It has been reported that pollution of the River Ravi - into which Lahore discharge its untreated waste water has meant 5,000 fewer tonnes of fish production per year.
Industrial waste water discharges
The major industries creating Environmental hazards are the manufacture of chemicals ( including pesticides), textiles, Pharmaceuticals, cement, electrical and electronic equipment, glass and ceramics, and pulp and paper board; leather tanning; food processing; and petroleum refining.
No systematic or complete survey has been done of the industrial pollution and characteristics of industrial pollution in Pakistan, although partial surveys, investigations of particular sources, and observations have shown the seriousness of industrial pollution in a number of locations. A preliminary study of hazardous chemical industries conducted in 1985 for the Environmental and Urban Affairs Division surveyed 100 plants scattered throughout the country. Only three, two of which were branches of multi-national companies, treated their wastes to commonly accepted standards. The remainder did nothing except dispose of their wastes in the most convenient way.
For all practical purposes, industries da not control their waste water effluents through process controls, waste recycling, or end-of-pipe treatment. In Kala Shah Kaku industrial area near24
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Lahore, for example, the various chemical industries, tanneries, textile plants, steel re-rolling mills, and other operations discharge effluents containing hydrochloric acid and high levels of organic matter directly into steams and canals. Biological oxygen demand levels of 193 to 833 milligrams per litre and mercury levels of 5.6 milligrams per litre have been measured. (The proposed interim relaxed government standards for these are 200 and 0.1, respectively). These discharges have rendered the mullah (drainage course) water unfit for irrigation use and livestock consumption, and have caused an annual reduction in the fish catch of 400 tonnes, valued at Rs. 10 million.
In the vicinity of Karachi, industrial pollution discharges combined with mangrove destruction and over-fishing have resulted is a sharp decrease in shrimp production, which translates into lower foreign exchange earning. Two large industrial zones in Sindh Province 00 SITE (Sindh Industrial Trading Estate) -- discharge large quantities of organic matter, heavy metals, oils and greases, and other materials into local rivers. In Korangi in Karachi, where LITE is located, 35 tonnes of suspended solids, 376 tonnes of dissolved solids, 2 tonnes of ammonia, and 1.4 tonnes of arsenic oxide, among other chemicals, are discharged into the city's already polluted harbour each day.
Leather tanning operations near Peshawar are polluting the Kabul River, threatening its use for domestic and irrigation purposes as well as its freshwater fishery. Over 235 industries in Faisalabad discharge high levels of solids, heavy metals, aromatic dyes, inorganic salts, and organic materials directly into the municipal sewers without any pre-treatment, polluting nearby agricultural land. Another area for concern is the contamination of shallow ground-waters is urban area near industrial plants as industrial wastes are discharged directly into or onto the ground. Ground-water pollution is often permanent, in that hundreds or even thousands of years may be necessary for pollution of years may be necessary for pollution such as toxic metals from tanneries to be flashed out of a contaminated aquifer. Surface waters, on the other land, Gin be rehabilitated if pollutant loading are reduced or eliminate.
The use of fertilisers has grown 7.1 per cent annually during the .Sixth Five-year Plan. Annual expenditure of pesticides currently amounts to Rs. 3.2 billion nationally. In 1986, 1.1 million tonnes of nitrogen and 93,000 tones of phosphate fertiliser were produced locally, and another 700,000 tonnes of fertiliser were
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imported. Pesticide imports have similarly grown rapidly, increasing from 7,083 tonnes in 1980/81 to 20.647 tonnes in 1986-
87 - a growth rate of 190 per cent over the six-year period.
Indiscriminate use of agricultural chemical, mainly fertilisers and various pesticides including insecticides, fungicides, and herbicides, is contributing to chemical pollution of the environment. Agricultural run-off from fields where these have been used incorrectly or inappropriately can raise the levels of these substances in waterways. The effects include excess nutrient loading from fertiliser run-off and subsequent uncontrolled algae growth in waterways, and pesticide contamination of waters, resulting in fish kills. Dead fish, apparently due to pesticides, have been reported on the banks of the Kabul River in certain season. Pesticides are of particular concern because of their bioaccumulation in fish and animal tissue and in the soil, and because of their persistence in the Environment.
Other risks include contamination of shallow wells used for drinking water supplies for villages and cities, and pesticide residues on cereal and vegetable crops where care has not been taken in their application, such residues may be harmful to humans. At least one case of poisoning resulting in a number of deaths, involving the pesticide enduring in foodstuffs, has been reported in Pakistan.
Increasing use of nitrogen fertilisers may also led to excess nitrate levels in groundwater are converted to more toxic nitrites in
• the stomach of adults and infants, and are known to cause blood disorders in infants. No studies to date have assessed groundwater contamination in Pakistan from pesticide or fertiliser use in agriculture.
The classic source of air pollution is the factory smoke stack. Such stationary point-source emissions are highly visible and represent a significant threat to those living nearby. By volume, however, they represent less of a threat to the overall health of Pakistanis than do the multiple mobile sources of the automobile and other vehicles. Nevertheless, the combined emissions of air pollution from industry, power generation, transportation, domestic activities (particularly energy use), agriculture, and commercial institutions are growing rapidly.
Industry and power generation are becoming major sources of carbon dioxide and sulphur dioxide emissions. The rapid increase in thermal power generating capacity currently underway will result in substantial increase in emissions of these two gas and26
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of nitrogen oxide from the burning of oil and coal in new generating stations. Pakistan's low thermal-value, high-sulphur coal reserves will cause a rapid increase in these emissions as they come into production to feed the thermal generating stations.
Similarly, use of natural gas, coal, and oil as fuels by industry is expected to cause a substantial increase in air pollution. The expected effects of these emissions, unless they are controlled at the source, include deterioration of soil quality in the vicinity of factories, potential damage to corps (particularly from sulphur dioxide and nitrogen oxides), and possibly human health effects. Many studies in a number of countries have quantitatively linked air pollution with respiratory disease, including lung cancer.
Vehicle emissions and urban air pollution
As the above mentioned figures indicate the truly dangerous pollutants to human health -- those that can cause bronchial irritation, hasten asthma attacks, and irritate the eyes arise primarily from non-stationary sources in urban areas. Motor vehicle emissions in Lahore account for approximately 90 per cent of the total annual emissions of hydrocarbons, aldehydes, and carbon monoxide, and for smaller but still the largest proportion of « the emissions of sulphur dioxide and nitrogen oxides. Metropolitan reliance on buses and light commercial vehicles also have various air pollution consequences. Old vehicles stay on the rods because of the absence of emission regulations, lack of enforcement of motor vehicles fitness regulation, and the owner's lack of caita to purchase replacements. Thus the average Pakistani vehicle emits 20 times as much hydrocarbons, 25 times as much carbon monoxide, and 3.6 times as much nitrous oxides in grams per kilometre as the average vehicle in the United States. As such, air pollution along busy roads and narrow streets of the main cities is an order of magnitude greater than would be predicted from the number of vehicles of the road.
The pollutanfs recorded are the standard emissions monitored throughout the world. Sulphur dioxide, a precursor of acid rain, is an irritant to the eyes, noes, and throat as well• as to the lungs. It is also phytotoxic, damaging plants. Aldehydes are particularly noteworthy for their obnoxious smell.
Carbon monoxide is considered to be the most toxic common urban air pollutant, since it reduces the oxygen carrying capacity of fhe blood. Carbon monoxide levels in the range of 8-30 parts per million (PPM) and 6-40 PPM have been recorded for Lahore and Karachi, respectively. Exposure for an eight-hour period at these levels is knows to cause temporary impairment of
nervous system function, including eye-sight sharpness. Hydrocarbons are an important source of particuiate air pollution in Pakistan's major cities. These substances are the precursors of photochemical smog, in conditions where exposure to sunlight changes the material into an eye and lung irritant. Smog is also know to inhibit plant growth. Nitrogen dioxide is the component of the family of nitrogen oxides that has the potential of the greatest adverse effects on human health and hence is the chemical fro of nitrogen oxides usually measured. In laboratory tests, nitrogen oxide levels of 100 PPM cause illness if breathed for a short time. Levels of 700 PPM are fatal if breathed for 30 minutes. The standard recommended by the World Bank for nitrogen dioxide is 0.05 PPM.
The most dangerous of vehicle-related emission, lead, does not appear in Table 3.6 because urban led emission levels have been measured only sporadically in Pakistan. In Karachi, ambient lead levels have been measured at between 0.924 and 0.13 micrograms per cubic metre. Estimated lead released from emissions to the air in Pakistan is 520 tonnes.
Lead is added to gasoline to increase the octane rating and to reduce engine knock. When led is ingested by young and growing children, it is deposited it the brain and has been shown to cause a reduction in intelligence quotient. Lead . from auto emissions is a particular hazard for inner-city residents living, working, or playing along heavily travelled urban roads. It is for this reason that all industrial nations have moved towards lead-free gasoline. In Britain, a reduction in the lead content of gasoUne from 0.06 per cent to 0.05 per cent ltd to a halving of blood lead levels among affected groups. Uncontrolled open burning of garbage is another source of urban air pollution. Such burning, which typically takes place at relatively low temperatures, has been found in the West to be a major source of dioxins, an extremely by weathering will eventually produce a harmless product, but before that happens the dump will be a malodorous home for rats and flies, and, via leaches, another source of ground water contamination.
Little information exists on the nature of industrial air emissions in Pakistan; neither comprehensive nor spot surveys has been reported. But observations in the vicinity of a number of industrial zones have shows the effects of these pollutants. In Kala Shah Kaku industrial area, gaseous emissions are believed to be responsible for adverse effects on downwind crops. The Punjab Environmental Protection Agency has recently begun preliminary
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air pollution surveys with the assistance of the institute for Public Health Engineering and Research at the University of Engineering and Technology (Lahore) and the Pakistan Council for Scientific and Industrial Research. Air pollution is primarily an urban problem where the density of industry and vehicles is sufficient to overcome the ability of the air to disperse the pollutants or dilute them quickly enough. In rural areas, air quality is not normally a problem except in the vicinity of particularly obnoxious and large discharge of pollutants. For example most cement plants in Pakistan have not installed equipment to control dust emissions, and pose a nuisance and a potential quantities of toxic industrial wastes have been dumped in municipal disposal areas or are being dumped directly into lands adjacent to factories with no record of their location, quantity or toxic composition. The experience in many countries has shows that such 'toxic real estate' has grave social and economic implications for the future; serious health problems among local residents, large liabilities for cleanup incurred by the industries, lowered property values, and considerable public expense for identification and rehabilitation of contaminated sites.
Pakistan has two ports (Karachi and Port Qasim) and four fish harbours either operational or under construction (Karachi, Pasni, Gwadar, and Korangi). Karachi port and harbour are the most used areas, and it is here that the greatest pollution in seen, both from vessels (illegally pumping out bilges and refuse), and from the port's oil terminal. An estimated 90,000 tonnes per year of oily discharge are pumped out within port limits. No oily ship waste reception or treatment facility exists within the port. Dredging operations, necessary to keep the approach channels open, also have a major impact. The shipping lanes in the Arabian Sea are some of the busiest in the world, and it is fortunate that Pakistan has not experienced a spill greater than that of the 'Akbar', an oil barge that sank and discharged 700 tonnes of crude in 1984. Pakistan has no capacity to cope with an oil spill, minor or major, or with any other kind of shipping accident with environmental consequences. Recently, another potential hazard has also come to light: the possibility of toxic waste dumping either at sea or, through the subterfuge or wrongly labelled containers or ships on land.