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Keeping the water supply system free of poisons

The New Straits Times, February 3, 2002

By Dzulkifli Abdul Razak

YESTERDAY was World Wetlands Day. It commemorates the signing of the Convention on Wetlands on February 2, 1971. Wetlands are important because they support a diverse number of species, including more than 20,000 water animals (some of which are endangered) by providing food sources, breeding grounds, and migratory resting places, to name a few.

Above all, as illustrated by this year's theme "Water, Life and Culture", wetlands are nature's treasure as they provide us with clean water, a vital resource for our own survival. For Malaysia, Tasek Bera is a classic example.

But this is not all. By the Convention's definitions, rivers, lakes, fresh water swamp, even rice fields are wetlands.

But preserving wetlands and protecting water resources are only part of the larger responsibility. Even though they are clean and pollution-free, there can always be other problems. Recently, the issues of water distribution for use and consumption to home via asbestos-cement pipes have been highlighted. Reportedly "a total of 255,000 km of asbestos-cement pipes" has been used to transport water nationwide over the last three decades, most of which reportedly were installed in the pre-war days (NST, Jan 26).

Not surprisingly then, they "are now in the process of gradual decay, easily bursting and prone to leaks". Such leaks could also be points of contamination from various inorganic compounds, some lethal like arsenic, and many other secondary contaminants such as chlorine and iron, causing not only the taste of water to change but also its appearance and odour.

There are many others like bacteria and fungi (www.epa.gov/safewater/mcl.html).

With respect to asbestos, although in general, the release of asbestos fibres into the air by the disturbance of asbestos-containing material for instance, during product use, construction and demolition work, poses well-documented hazards, its dangers in drinking water arising from natural sources or through the wear or breakdown of asbestos-containing materials, in water supply systems, seems less clear.

According to the World Health Organisation (WHO), "research findings up to date are inconclusive to demonstrate a health effect from ingested asbestos fibres via drinking water." At the same time, however, its statement in 1986 (Sept 10), cautioned that when available, substitute materials evaluated safer than chrysotile (asbestos fibre) should be used.

In contrast, a 1990 report of the US Environmental Agency (EPA) categorically states that: "After weighting the available information, EPA believes that there is evidence of a strong casual relationship between asbestos exposure and gastrointestinal cancer excess... Evidence suggests that cancers in the oesophagus, larynx, oral cavity, stomach, colon and kidney may be caused by ingesting asbestos." More specifically, the evidence includes: (a) a statistically significant increase in gastrointestinal cancer found in 10 of 23 epidemiological studies; (b) a consistent relationship that exists between increased gastrointestinal cancer risk and increased lung cancer risk (approximately 10 to 30 per cent of the lung cancer excess); and (c) it is biologically plausible that asbestos could be associated with these tumour sites because it is conceivable that the majority of fibres inhaled are cleared from the respiratory tract and subsequently swallowed, allowing the fibres to enter the gastrointestinal tract (additionally, fibres may be swallowed directly).

In any case, asbestos-cement pipes are only one part of the problematic water distribution system; the other being lead pipes. Like asbestos, lead too has been shown to be present in drinking water primarily as a result of the corrosion (especially with soft water), or gradual wearing away, of leaded materials in the piping system, such as service pipes, plumbing fixtures and lead-based solder.

This is more likely to happen when water stands in lead pipes or plumbing systems containing lead for several hours. In cases when the water is hot, more lead can dissolve, posing even more significant risks to health as much more lead enters the body. Over time it can lead to lead poisoning.

This concern has been expressed many times in the Poison Control column, but we have yet to see any positive response, as also on the asbestos-cement issue.

Rightfully, there should be no slip-ups in this matter because like asbestos-cement pipes, lead pipes have also been used since pre-war days and have suffered wear and tear as well. And like asbestos, lead too can pose various health hazards, especially when it leaches unknowingly into our drinking water systems, particularly in our hot climate.

Unlike asbestos, however, the dangers from ingested as well as inhaled lead are well-documented. It is well established that the greatest risk is to pregnant women and young children. At levels that would not hurt adults, children can experience impaired mental and physical development of growing bodies.

Lead builds up in the body over many years and can cause damage to the brain, red blood cells, and kidneys.

In fact the US EPA and various US municipal water suppliers have expressed concern about lead in drinking water. So, too, should the Works and the Health Ministries in urging the replacement of lead pipes.

In the US, since 1996, under the Federal Law water suppliers are required not only to have a programme in place to minimise lead in drinking water, they must also replace each lead service line if the line contributes to lead concentrations more than 15 parts per billion (ppb), or 0.015 milligrammes per litre of water.

Lead contamination from water allegedly can contribute 10 to 20 per cent of a person's exposure to the heavy metal as in the case in US, with lead paint being the most frequent source of exposure.

Under such circumstances, the Works Ministry must be commended for swiftly taking up the issue and recommend the replacement of asbestos-cement pipes (NST, Jan. 27), and no doubt lead pipes too.

At the same time however, it must insist on the full protection of the workers involved in all the replacement work. This is in view of the fact that any exposure to the toxic materials, be it asbestos or lead, can be deadly. In case of the former, just last April, a former pipe worker in the US was diagnosed with a rare and terminal cancer (mesothelioma) after being exposure to "lethal asbestos dust during the 1980s." The court awarded him more than US$20 million (RM76 million) in damages.

Hence, while the complete renewal and modernising of the water piping system nationwide is being contemplated and executed, the authorities must not relent.

Regular testing of drinking water, to determine if it contains unacceptable levels of any undesirable contaminants, must be conducted and the results shared with the public.

This is important in order to keep the public informed, especially in view of the fact that many pollutants in drinking water systems cannot be easily detected by sight, taste, or smell including asbestos and lead.

Keeping the public constantly involved would encourage them to take a strong interest in this issue and support efforts to protect drinking water, while preserving the wetlands.

Only when all these are properly put in place can we be assured of a sustainable and safe drinking water system nationwide.

Recommended site: http://www.epa.gov/safewater/hfacts


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