PART 2: WHAT HAPPENS WHEN IT RAINS?
MANILA, MARCH 27, 2009 (STAR) STAR SCIENCE By Michelle C. Almendrala, Ph.D - (Second of two parts) In February 2008, the Department of Health declared a typhoid fever outbreak in Calamba City. It was suspected that the outbreak, which affected 1,700 people, resulted from water contamination (Senate, 2008). A second outbreak of typhoid in March 2008 left about 150 people hospitalized in the island of Zumarraga, off the eastern half of Samar Island. Epidemiologists suspected that the outbreak was due to the heavy rains which washed sewage into open wells that residents use for drinking water. Over 90 percent of all sewage generated in the Philippines is not treated. Water-borne diseases accounted for nearly 31 percent of all reported illness from 1996 to 2000 and economic losses from water-borne diseases alone exceed P2.3 billion a year.
Contaminated surface waters also alter the metabolic processes of the aquatic species that they host (http://en.wikipedia.org/wiki/Species). These alterations can lead to death, such as fish kills, or alter the balance of populations present. Surface runoff of pesticides, such as DDT, can alter the gender of fish species genetically, which transforms male into female fish. Excess nutrients can cause algae blooms. Fish and other aquatic organisms can’t exist in water with low dissolved oxygen levels.
Polluted water often affects drinking water sources; this, in turn, can affect human health and increase drinking water treatment costs. A reality that we all have to face — “tap water is no longer safe.” About 58 percent of the groundwater in the Philippines is contaminated by human wastes, petroleum, fertilizers, toxic metals like arsenic, and other poisonous chemicals. The tap water that was readily available from our own faucets, as far as I can remember in the 1980s, is not safe anymore for drinking. Before, water was free, now it will cost us around P500 to P1,000 per month just to have safe drinking water. But there are questions that we still have to answer. How safe is our bottled water, as well as the purified water delivered to us from the water store? Is bottled water better than tap water? Although bottled water is very popular, in most instances, it is no better than tap water, and tap water is certainly less expensive (Ingham, 2003).
Research shows that some of the bottled water is not so safe for drinking. They are not as clean as we think. We hold the false assumption that purified or bottled water is safer and better than tap water. There are several brands of bottled water now available in the market, but about 40 percent of these merely contain tap water in plastic bottles. Bottled spring water is often subject to the same contaminant pressure as tap water. The Environmental Working Group (EWG), a non-profit organization in the US, consists of four teams of scientists, engineers, policy experts, lawyers, and computer programmers. EWG found an alarming array of contaminants in 10 brands of US bottled water which includes cancer-causing by-products of chlorination, fertilizer residue like nitrate and ammonia, industrial solvents, pharmaceuticals like Tylenol, heavy metals and minerals including arsenic and radioactive isotopes, and other industrial chemicals. There are some health consequences of drinking polluted bottled water such as increased risk of growth of cancer cells. At the University of Missouri, it was found that bottled water stimulated a 78 percent increase in the growth of breast cancer cells compared to a control sample (Evita, 2008).
So what can we do to make sure that the water we drink is safe? The best answer to enjoy plenty of water in a safe manner is to drink filtered tap water instead of bottled or unfiltered tap water. The next question is, what is the best filtration system that will be able to remove most of the water contaminants that are present in our current water supply? Next time, I will discuss the need for a membrane separation technology in the Philippines for purifying water, not only for drinking use, but also for industrial applications.
Chief News Editor: Sol Jose Vanzi
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