A polluted environment:

Hazardous to your health

Dr. Udaya RALAPANAWA

THE signs of environmental stress grow as the world’s population increase: worn out farmlands eroded hillsides, polluted water, parched grasslands, smoke - laden air, depleted ozone and treeless ranges.

Each year about 17 million hectares of tropical forest vanish. Fish catches are levelling off. Cities are clogged with refuse and polluted water and air, cause disease.

BETTER HEALTH: A longer life with less sickness is very important for a better standard of living. Yet worsening environmental conditions in many areas threaten to reverse gain made in public health over the last several decades.

Millions of people die every year from illnesses caused by environmental pollution, and millions more suffer chronic disabilities such as diminished physical strength and endurance, lower intelligence, and lack of alertness.

The poor suffer most because they have no choice but to face unsanitary living conditions, malnourishment, exposure to infectious organisms and toxic chemicals, and lack of health services.

Crowding

For the urban poor, high population densities contribute to many health problems. Tuberculosis, viral infections, and other contagious diseases spread rapidly in crowded cramped conditions.

Migrants, attracted to urban industrial areas in the hope of getting jobs, are forced to drink unsafe water and inhale toxic fumes since areas open to squatter settlements are often highly polluted places shunned by the more affluent.

In densely populated coastal cities near polluted fishing areas, chronic intestinal and stomach disorders are common among poor families who eat local fish.

In rural areas high population densities diminish per capita food production. Hunger and malnourishment can result.

Malnutrition results in weakened condition, poor health, impaired intellectual development, and low productivity. About one African in every three and about one Asian in every five does not eat enough to be fully productive.

Water pollution and water scarcity

One of the most deadly and widespread pollutants of water is untreated human waste. In developing countries two in every five people lack proper sanitation and sewage is routinely released into water ways untreated. Water polluted with sewage is a major source of illness and death in developing countries.

Each year diarrhoea, the third most common cause of death in developing countries (after respiratory disease and circulatory disorders), kills more than four million people - mostly children.

Other diseases spread by human waste in water include typhoid, which afflicts 70 million people in developing countries: amebiasis (amebic dysentery), 500 million, hepatitis A (an unknown number of people affected but 14,000 deaths (annually); giardiasis, 250 million; gastroenteritis, 100 million; and cholera, 300,000.

The various intestinal infections caused by unclean water sharply reduce a person’s ability to digest and assimilate food. Thus, cleaning up water supplies may be the most cost-effective method of improving nutrition in developing countries.

Altogether, diseases caused or aggravated by polluted drinking water kill an estimated 10 to 25 million people each year. Most of these deaths could be prevented if sanitation and living conditions improved.

Inadequate water supplies often lead to poor hygiene, which allows diseases such as trachoma, scabies, yaws, conjunctivitis, leprosy, and skin sepsis and ulcers to flourish.

Unclean water and poor sanitation also are associated with diseases caused by insects that breed near stagnant water, organisms living in water, and worms in the soil.

Air pollution

The air that most city-dwellers breathe is a hazard to their health. About 70 per cent of the world’s urban residents breathe air that is unhealthy. An additional 10 per cent breathe air that is only marginally healthy.

In developing countries the continued use of leaded fuel for vehicles, combined with traffic congestion, creates a serious health hazard. Many rural residents are also exposed to air pollution, through wind-born pollutants and soot from indoor cooking and heating.

Air pollution contributes to such health problems as cancer, respiratory, heart, and lung diseases; genetic defects; and mental retardation. The young, the old, and people with cardio-respiratory disease face the greatest risk.

Hazardous wastes

Millions of people throughout the world are exposed to hazardous wastes from industrial plants, power generating stations, refineries, tanneries, and hospitals. Once these chemicals have been dispersed into waterways, landfills, and air, it is difficult and very expensive to remove them.

Health effects of exposure to hazardous wastes include cancer, birth defects, and damage to the liver, kidney, brain, skin, nervous system, and eyes.

Similarly, fertilisers and pesticides may cause severe illness in more than one million people annually. Farm workers are at the highest risk, but waterways carry fertilizer and pesticide residues long distances.

Slowing population growth, as a long-term means to help control increases in air and water pollution and to slow degradation of arabal land, will contribute to a cleaner, safer environment.

In turn, better environmental conditions will lead to a healthier and more productive population. Instead of trying to support ever larger numbers of people at minimal levels of health, gains in productivity can be directed to improving people’s lives.