Undeveloped production systems, in particular intensive animal husbandry in densely populated areas, with livestock in close proximity to humans, are the perfect breeding ground for new diseases. SARS as well as avian influenza are fresh examples

About one quarter of the diseases worldwide can be accredited to environmental causes, with 40 per cent of the sufferers being children under five.

Among the ten most significant dangers to the developing countries with high-mortality rate are unsafe water and sanitation and hygiene problems. Just about 80 per cent of each and every type of infectious disease is caused by unclean water. Globally, 1.1 billion people lack access to safe water supply and 2.4 billion to adequate sanitation.

In East Asia and the Pacific, 48 per cent of the population have access to improved hygiene while in South Asia, merely 37 per cent have such access. Inadequate water and insufficient hygiene lead to ill health.

Over 200 million people in nine Asian countries, more often than not living in rural areas, are at risk of arsenicosis, cancer and eventual death from the long-term use of groundwater infected with arsenic.

Arsenic toxicity has a pervasive effect on all systems in the body and long-term consequences on children, slowing their cognitive expansion and cerebral ability. There is no known medical cure for arsenicosis.

The only sure way of preventing arsenicosis is to avoid drinking impure water. Furthermore, extreme fluoride in water causes dental and skeletal fluorosis.

In the Asian and Pacific area, indoor air contamination poses the uppermost health risk. Contact with smoke from solid fuel like wood, dung, coal and agricultural remains increases the amount of contamination.

Women and children are the most at risk. Indoor air pollution causes an accumulation of pollutants, such as coarse and fine particulate matter, carbon monoxide, oxides of nitrogen, benzene, toluene and formaldehyde, in the bodies of those exposed to indoor air pollution.

Epidemiological evidence suggests a link between indoor air toxic waste and respiratory infections, TB, cancers, low birth weight and greater infant and prenatal mortality. Lead emissions are also a serious problem in the region. Lead is found in rice, vegetables and drinking water, leading to high levels of lead in the blood.

Apart from its instant toxic and carcinogenic effects, air contamination affect the environment and health in other ways. Some air pollutants descend as acid rain. Acid rain causes ecological degradation which impacts ecosystems, increasing health hazards.

Ozone depletion, associated with use of ozone-depleting chemicals, is expected to augment UV-B radiation, resulting in the oppression of immune systems and skin cancer. In South East Asia, 70 million people are seasonally affected by air pollution due to forest fire.

A number of pesticides are associated with cancers, miscarriages and inborn malformations. Agrochemical poisoning and agro-machinery accidents cause diseases, injuries and death that are underreported.

Small-scale farmers are especially vulnerable to the exposure to chemical fertilisers and pesticides that are widely used in the region, and to equipment-related hazards aggravated by sustained hard physical labour with old and poorly maintained gear.

A lot of new infectious diseases have emerged because viruses have jumped the species fence from flora and fauna to humans. Undeveloped production systems, in particular intensive animal husbandry in densely populated areas, with livestock in close proximity to humans, are the perfect breeding ground for new diseases.

SARS as well as avian influenza are fresh examples. These diseases affect not only humans, but also flora and fauna and vegetation. They also threaten food safety and livelihood. Thus, these diseases have themselves turned out to be drivers of environmental alteration.

A notorious issue in foodstuff production is the use of genetically modified organisms. There is vigorous global debate on the large-scale use of genetically modified organisms in developed countries when their long-term penalty on human health has not been well-known.

Foodstuff from genetically modified crops has caused anxiety. Plastic is extensively used for wrapping food.

These substances could be released if ingested. Vast quantities of microscopic plastic fragments are building up in oceans. The accumulation of plastic wreckage in parts of the central Pacific Ocean is six times greater than that of resident plankton, the very foundation of the food chain.

There is indication that plastic debris is being ingested by marine organisms and might go into the food chain.

Haphazard waste disposal is a chief health danger. Non-biodegradable plastic waste constitutes a main part of waste. Plastic floats in water; it accumulates and absorbs toxic hydrophobic chemicals from other sources. Artificial waste also clogs sewerage systems, causing severe hygiene problems.

In spite of some progresses made since the Basel Convention on the Trans Boundary Movement of Hazardous Waste came into force, large amounts of hazardous waste, including electronic waste, are still exported to developing countries in the region. Recycling is often absent and the burning of plastic and dumping are common.

The unsafe disposal of hazardous domestic medical and manufacturing waste pose severe health risks to people in the region. Governments in the region should pay serious attention to ecological health.

Rajja is medical doctor serving with Narayani Sub-Regional Hospital