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Water pollution

Over the years, water pollution has emerged as a major issue. Pollutants include pathogens, organic matter, nutrients, heavy metals and toxic chemicals, sediments and suspended solids, silt and salts.

South Asia - particularly India - and Southeast Asia are facing severe water pollution problems. Rivers such as the Yellow (China), Ganges (India), and Amu and Syr Darya (Central Asia) top the list of the world's most polluted rivers (World Commission on Water 1999). In cities in the developing countries of the region, most water bodies are now heavily polluted with domestic sewage, industrial effluents, chemicals and solid wastes. Most rivers in Nepal's urban areas have been polluted and their waters are now unfit for human use, while drinking water in Kathmandu is contaminated with coliform bacteria, iron, ammonia and other contaminants (UNEP 2001).

Water pollution has affected human health. In the Pacific Islands, especially in some atoll communities, use of polluted groundwater for drinking and cooking has led to health problems such as diarrhoea, hepatitis, and occasional outbreaks of typhoid and cholera. Groundwater in districts of West Bengal, India, and in some villages in Bangladesh, for example, is contaminated with arsenic at levels as much as 70 times higher than the national drinking water standard of 0.05 mg/litre. While pollution is a factor, arsenic contamination is also due to natural phenomena. According to one report, 'With the majority of the country's 68 000 villages potentially at risk, UN scientists estimate that the arsenic may soon be killing 20 000 Bangladeshis a year' (Pierce 2001).

Improved water supply and sanitation coverage: Asia and the Pacific

In the year 2000, 81 per cent of Asians had access to improved water supplies but only 48 per cent - the lowest of any region - to sanitation

Source: WHO and UNICEF 2000

Inadequate water supply and poor sanitation cause more than 500 000 infant deaths a year as well as a huge burden of illness and disability in the region UNEP 1999). Some 8-9 per cent of the total Disability Adjusted Life Years (DALYs) are due to diseases related to inadequate water supply and poor sanitation in India and other countries (World Bank 2000). Cholera is prevalent in many countries, particularly those where sanitation facilities are poor such as Afghanistan, China and India (WHO 2000).

Of the global population without access to improved sanitation or water supply, most live in Asia WHO and UNICEF 2000, see map left). In the Southwest Pacific sub-region, water supply and sanitation appear to be relatively good, with 93 per cent of the population having access to improved sanitation and 88 per cent to improved water supply (WHO and UNICEF 2000). These figures are strongly biased by the large and well-served population of Australia, however. Only an estimated 48 per cent of the Asian population has sanitation coverage (WHO and UNICEF 2000) - less than in any other region of the world. The situation is worse in rural areas, where only 31 per cent of the population have improved sanitation, compared to 78 per cent coverage in urban areas.

During the past decade, several countries have started to address the water quality problem by implementing large-scale programmes and action plans to rehabilitate degraded streams and depleted aquifers. These programmes are typically given legislative or statutory authority such as that provided by Thailand's National Water Quality Act, the Philippine Water Quality Code, India's Environment Protection Act, China's Water Law and the Republic of Korea's Water Quality Preservation Act (UNESCAP 1999). Success stories with respect to rehabilitation and protection of water quality of rivers come from those countries where water policies promote a multisectoral and multidisciplinary approach to the management of water resources.

Water pollution in Australia
In Australia, the quality of water in many inland waterways has declined due to human activities within catchments (Ball and others 2001). Sediments, nutrients and toxic materials as well as excessive growth of aquatic weeds have affected aquatic ecosystems. Response measures include the Urban Storm Water Initiative, the Industry Partnership Programme and Waterwatch Australia that together aim to monitor and improve the health of urban waterways. A number of state and territory-based programmes have also been introduced, together with community programmes such as Streamwatch and Waterwatch. In addition, local authorities are developing storm water management plans for urban catchments with financial support from state and territory agencies. Storm water is increasingly seen as a resource to be collected and utilized rather than a waste for disposal.
Source: Australia State of the Environment Committee 2001

Clean-up campaigns for rivers, canals, lakes and other water bodies have become widespread. The programmes have often been successful in improving water quality and, occasionally, have led to the adoption of new water quality standards and water use regulations. They have also increased awareness of the need to reduce pollutant loads through wastewater treatment, reuse and recycling of sewage and industrial wastewater, introduction of low-cost technologies, and strict control of industrial and municipal effluent. There have been a number of successes in water reuse and recycling in the industrialized countries of the region.

Water quality has been improved in China, Japan, the Republic of Korea and Singapore as a result of initiatives to address water pollution. In Japan, the government has set environmental quality standards and made remarkable improvements: in 1991, 99.8 per cent of water samples met standards for heavy metals and toxins in Japan (RRI 2000). In 2000, the rate of industrial wastewater treatment across China was 94.7 per cent (SEPA 2001). Action in Singapore means that Singaporeans can now enjoy drinkable piped water straight from the tap.