Environmental pollution –a silent killer

30 Jul 2007


Gobal warming is destroying some of the world’s tallest and most stunning mountains. Climate change caused by green house gases such as carbon dioxide is considered one of the biggest long-terms threats to mankind and could bring higher sea levels devastating floods and droughts. Atmospheric temperatures have also been rising for the past 50 years. Climate is changing and it is widely accepted that this is due to greenhouse effect.

Evidences over the past decade indicate that air pollution particularly fine particles can trigger strokes and heart attacks. Air pollution was linked to a greater number of deaths from heart and respiratory diseases, according to the Heart Association Review of nearly 200 published studies.

Pollution 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 -- textile, leather, sports goods, surgical instruments and carpets, which are increasing environmental pollution.

Among these, leather and textile industries are the major source of waste water that is polluting rivers and lakes causing environmental problems in major cities and resulting in serious impact on human health. It refers to Pakistan Human Rights Commission Reports in1998 which quantified loss to Pakistan economy by environmental degradation at $1.65 billion.

The loss is in addition to the impact of environmental degradation on health and lives.

Production of cloth, the ADB study points out, requires a large number of detergents, dyes, acids, soda, salts enzymes which lead to a large amount of wastewater.

In leather tanning, a large quantity of chemicals such as sodium chloride, ammonium sulphate, pigments and dyes are used. If not treated, waste-ware from both these industries have serious impact on environment and human health.

The industrial areas of Karachi, Lahore, Faisalabad, Peshawar, Multan, Hyderabad etc. are confronted with problem of higher degree of environmental pollution. Under these circumstances in the severely-affected areas vegetation has been totally wiped out from the growing areas.

There is a report that air pollution in Karachi, Rawalpindi and Lahore was 6.4 times higher than the World Health Organisation’s (WHO) guidelines, and 3.8 times higher than Japanese standards in recent years.

Around 6,113 tons of garbage is generated in Karachi daily, out of which only 5,057 ton is disposed of. In a city of over 14 million, this is a major contributor to filth that hangs over the city.

There are three types of garbage -- municipal waste, hospital waste and industrial waste. Karachi is known for dust allergy as it is polluted with dust particles and vehicular emissions that also contain carbon dioxide and sulphur.

Karachi’s atmosphere is badly affected by motor vehicles plying on city roads. The city had a total of 2,177,315 vehicles by the end of 2005.

These included 540,063 motorcycles, 634,531 cars and jeeps and wagons, 1,658,918 rickshaws, 49,967 taxis, 99,247 buses and minibuses, 1742,957 trucks, 198,883 delivery vans and pick-ups. An average of 10 vehicles comes on the road after every one hour in Karachi.

Ten years ago in 1993, the total number of vehicles was 832,885. Within 12 years the number has jumped up to 2,177,315. Such a big number of vehicles is causing colossal damage to the environment and proving to be a serious health hazard.

According to a report, industrial emissions and automobile exhaust are a source of asthma. Carbon monoxide (CO) is produced when fuels such as gasoline is burned. As it is colourless, tasteless, odourless and non-irritating, it can affect the exposed person without 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 inhibited, 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.

Atmospheric 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. Sulphur dioxide, which causes formation of acidic condition in the atmosphere, causes damage to crops and forest, erosion of buildings and structures.

During the last century an increase of 12 per cent of CO2 was recorded which caused the global warming.

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 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, anaemia, 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 mercury 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 athero-sclerosis 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.

Suggestions: With the recognition that global environmental protection is one of the most important and common causes for every body. Pollution may cause increased illness, contamination of surface water, impaired growth of agricultural crops, deterioration of materials and loss of amenity.

Therefore, 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 organisation of seminars and symposia. We should discourage smoking.

Science provides many practical solutions to minimise the present levels at which pollutants are introduced into the environment and for creating up environmental problems. In our everyday life, a great deal can be done to minimise pollution, if we take precaution while recycling materials whose production create pollution, and if we act responsibly with household chemicals and their disposal.