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Water: the drink of life and death.

Chemical contamination of water is a lesser problem in Pakistan because of relatively fewer industries polluting it though the problem is on the rise exponentially. The major problem in Pakistan is the contamination of water supply with microbes. Five categories of pathogens (the disease causing microbes) are found in water: bacteria, viruses, protozoa, worms and fungi. The principal bacterial waterborne diseases are typhoid and cholera, both of which are a major cause of death in Asia, Africa and Latin America.

We cannot survive without water but infected water also kills: Dr. Sarfaraz K. Niazi writes about the importance of water for human health and how it should be purified.

Two thirds of the planet Earth is covered with it and ironically two-thirds of our body is also made up of this essential chemical - water a necessity and an amenity. Wholesome and abundant, it supports and enriches life. Unwholesome or scarce, it is a threat to health and to life itself. Four billion years ago it started to rain. The molten globe that was the Earth had slowly begun to cool, Most of the hydrogen gas and oxygen in the atmosphere combined to form water. The total amount of water created four billion years ago has changed little. Fresh waters run to the sea and become saline, but evaporation from seas and precipitation on land restores these fresh waters continuously keeping their quantity fixed. The total amount of water in the world is about 1,500 million cubic kilometers of which only about 0.2 per cent is fresh water. This amounts to about five million litres of water for each of the five billion persons inhabitating this Earth - a very large quantity considering the fact we only use less than 40,000 litres in our lifetime.

Uneven distribution of fresh water sources coupled with inadequate means to distribute it leaves about two billion people of the world without access to safe water. Only one-fifth of the world countries have good drinking water despite celebrating the 1980s as the Decade of Water. The supply of fresh water is continuously dwindling because of the use of water over and above its replenishment. Pakistan is one of the countries where we are utilising over 20 per cent of water resources per year, the threshold point. In Pakistan, the per capita availability of water is about 2,000 litres per day, 97 per cent of it goes to agriculture, making Pakistan one of the top most countries in artificial irrigation.

The survival mechanism of the body demands water by creating thirst, a warning signal which must be taken seriously. A person can survive on three-quarters of a litre over 24 hours, but the normal requirement is around 2.5 litres per day. Almost half of it comes from our "solid" foods. We exhale about 0.4 litres, sweat 0.5 litres, urinate 1.5 litres and lose. 0.1 litres in faeces to a total of about 2.6 litres per day. On the supply side we get about one litre from food, 1.2 litres from drinks and about 0.3 litres from burning of nutrition in the body. For tropical climates and at high altitudes we need 6-7 litres per day. When doing hard physical work, exercising or in extreme heat we can lose up to two litres of fluid an hour. Diarrhoea and vomiting can quickly rob the body of its vital fluids and lead to dehydration. Fluid loss is much more critical in children and infants, with the symbols arising much sooner than in adults.

Unlike animals, humans have rather poor thirst control. Even if the body is signalling its need for liquid, our feeling of thirst disappears after we have drunk only half the liquid lost. The first symptoms of fluid deficiency is not thirst but general tiredness and reduced energy. Drinking water appears to impart energy whereas it simply restores body symptoms.

Except for pure distilled water, waters from different sources have different composition because of the chemical and microbial contamination. The potable or drinkable water is a subject of many worldwide regulations to protect its quality. The US Public Health Service, WHO, the European Commission, all have stringent requirements for the quality of potable water mandating minimal levels of toxic chemicals and disease causing microbes.

Chemical contamination of water is a lesser problem in Pakistan because of relatively fewer industries polluting it though the problem is on the rise exponentially. The major problem in Pakistan is the contamination of water supply with microbes. Five categories of pathogens (the disease causing microbes) are found in water: bacteria, viruses, protozoa, worms and fungi. The principal bacterial waterborne diseases are typhoid and cholera, both of which are a major cause of death in Asia, Africa and Latin America.

Discomfort caused by water is typified by Montezuma's revenge. Different floras (types of microbes, not necessarily all harmful) in water can produce instant gastroenteritis or upset stomach even though water may be disinfected. It is because even if bacteria are killed, their toxins remains there to irritate the walls of the intestine. Drinking contaminated water does not produce immunity as erroneously believed by some. Though the effect of some toxins may be reduced upon repeated exposure, a drink full of salmonella will cause typhoid.

Another major source of disease from water is through waterborne viruses. This includes mainly the polio, cox, echo, adeno, rota, reo and hepatitis type A virus. Legionnaire's disease is also spread through water. Unfortunately, viruses are not included in the world standards of water supply because of the difficulty in detecting them. Even treated waters may contain substantial levels of viruses which initiate subclinical infections or infect Susceptible individuals.

Water leaving the filtration plants might be of acceptable quality; what happens to it before it reaches the tap in your home, makes it often unacceptable. The rotting supply lines and the leaking sewage disposal line often have common meeting grounds. Storage in underground tanks in unsanitary conditions only compounds the poor quality of water. Stagnant water is a fertile breeding ground for bacteria. We conducted a test of water quality, sampling from different sites in Karachi. Whereas these met the WHO requirements for total dissolved solids (of less than 500 ppm), they failed in microbial test.

What should one drink then? Certainly, not the tap water, unless it is properly disinfected. Since we cannot do much about the quality of water supplied (O.K. try fighting the KWSB), we must take all measures within our control to purify our supply of drinking water. First, it must be believed that the water supplied into our homes is contaminated with disease causing microbes, even if it comes from an urban well. You can bet on it. We begin by thoroughly cleaning the tanks for water storage at least twice a year to remove debris collected at the bottom. Then we disinfect the stored water by chlorinating it regularly. It is more important if water in your homes comes through tankers. Finally, we boil it before drinking.

Though chlorination may often add a bad taste to water and create the risk of reacting with organic substances to produce offending chemicals if over done, it is probably the only practical means of disinfecting water supply. The most ready source of chlorine for household use is sodium hypochlorite solution or liquid bleach that is widely available. The efficiency of chlorine in killing bacteria depends on how bad the water is If it is turbid and heavily contaminated with microbes, it will require much larger quantity of chlorine. Generally, if one half to one per million of free chlorine is made available, it should be sufficient. This translates to about 370 ml or about one and one-half glass of liquid bleach for an average 6ftx6ftx6ft tank with a capacity of about 6,000 litres. If two thousand litres are used per day, about 133 ml or one-half glass of liquid bleach should be added per day.

Several other methods of water disinfection are highly touted in the media. These include ultraviolet light treatment, filtration, storage in metal lined containers and use of water purification tables. Whereas use of water purification tablets is reliable if appropriate concentration is used, this method is too expensive to be of any value for daily use. The use of ultraviolet light to sterilise cannot be successful for home use because you cannot assure that it is working well all the time. If water is turbid, as is the case most frequently, ultraviolet radiation efficiency decreases substantially.

Filtration through ceramic candles and paper filters is quite risky and never reliable in disinfecting water. Dirty water chokes the filters quickly and promotes growth of bacteria on the surface of filters. The water coming out of filters may even be more contaminated than the water going in. Filtration alone cannot be recommended for water purification.

Given the inconsistent quality of water it is important to assure that whatever treatment is given it is successful at all times. The only such treatment is the boiling of the chlorinated water. Boiling not only removes chlorine, improves taste, but assures destruction of disease causing bacteria. Ice cubes should also be made only from freshly boiled water. Freezing water does not kill bacteria.

An argument against the use of boiled water recently brewed in the columns of some newspapers. The argument is that boiling water increases mineral content (due to water evaporation) that can be harmful to the kidneys. Boiling water for 20 minutes as recommended increases concentration of minerals but it rarely goes over the limits for drinking water. The poor quality of tap water has brought bottled waters in vogue in Pakistan. Packaged waters dates back to the 16th century. The first packaged water came from the resort town of Spa, in the Belgian Ardcnnes.

Mineral waters are also popular because of their health notion. In mid 1900s it became fashionable to serve sparkling mineral water in restaurants. Surprisingly, even today, many people use mineral waters because they believe it adds to vitality and vigour. Regardless of the stereotype image of mineral waters, they are sold in Pakistan mainly as a healthy substitute to drinking water. Unfortunately, the quality of mineral waters manufactured and sold in Pakistan is not consistent. We tested the two top-selling brands of mineral waters. Both of them had too many bacteria. One was even laced with Salmonella. It is a sheer audacity to label water, "free from bacteria" because it never can be. And it need not be. As long as the total bacteria count is low and pathogens are absent it is acceptable. Another argument against the use of mineral waters in Pakistan, besides their cost, pertains to the tropical climate of Pakistan, where water dehydration is common and the use of high mineral liquids is contraindicated to protect the kidneys.

Common substitutes to water drinking are soft drinks, most of which are very acidic and microbes do not survive in them. In our test, all bottled carbonated drinks passed the microbial test limit for waters. They can be good substitute of water for bacteria-free fluid. However, liquids with a high concentration of sugars remain longer in the stomach. They are unsuitable for quickly restoring lost fluid.

Tea and coffee are often used in place of water. Coffee, tea and alcoholic drinks undermine the body's fluid equilibrium. They drive more water out of the body than they contribute. So, in the end we conclude that there is no better drink than water-used intelligently. Used ignorantly, as it is done inevitably in Pakistan, it is the greatest menace to health.

Water Kills!

Almost 80 per cent of all diseases and 40 per cent of all deaths in Pakistan are associated with diseases spread through water. Worldwide every day 25,000 children die from illnesses they have contracted through polluted water. Yes, water kills.

Boiling water - The Right Method

- At least 20 minutes of continuous boiling - Water bottles sterilized by boiling - Bottles rinsed with boiled water - Filled bottles stored at cool temperature - Discard after 24 hours if not refrigerated - Discard after 48 hours if refrigerated

The Stages of Dehydration

What happens when you lose body water: - 3% loss: secretion of saliva and urine

is reduced - 5% loss: performance level drops,

pulse rate increases, body

temperature rises. - 10-12% loss: impaired mental abilities,

difficulty in swallowing, general

breakdown of main body function. - 20% loss: Death.
 Testing Drinking Liquids in Karachi!
Source Bacteria Pathogens
Water from Tanker, Clifton millions + Present
Tap Water, Landhi millions + Present
Mineral Water Brand A 220,00 Present
Mineral Water Brand B millions + Absent
Soft Drink, Brand A 0 Absent
Soft Drink, Brand B 0 Absent
Soft Drink, Brand C 65 Absent
 Limits: Total bacteria: not more than 1,000/100 ml;
Pathogens: absent
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Title Annotation:microbial contamination of water
Author:Niazi, Sarfarz K.
Publication:Economic Review
Date:Aug 1, 1992
Previous Article:Health-sector-1991-92.
Next Article:Aga Khan Hospital: in search of excellence.

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