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Thursday 18 April 2013

HOW SUNLIGHT AFFECTS ‘PURE WATER’


Water is one of the most significant necessities of life and remains indispensable for man. Of all the uses of water, one of the most important is probably drinking, and this could be attributed to the fact that about 64 per cent of the body is made up of water and it is the medium through which most biochemical processes in the body take place.


Owing to the epileptic and most times, total nonexistence of public pipe borne water, bottled and most especially, sachet water (pure water) has become the stay for most. In fact, a recent survey showed that sachet water business is a multi-million naira industry and the fastest selling commodity in Nigeria. Owing to its ubiquity, it has raised a lot of concern.

Environmentalists have continued to bemoan the environmental impact of sachet water, stating that the packaging, which is made of non-biodegradable synthetic polyethylene (polythene), does not decay, decompose or corrode, and when burnt, produces oxides of carbon, nitrogen and sulphur which can harm man and the environment. They have also drawn attention to its potential at causing floods, since the used sachets are improperly disposed off but rather thrown in the streets and gutters, thus blocking the already poor drainage systems. Health experts have equally expressed worry especially on quality and hygiene in production, packaging and distribution, especially given the fact that the World Health Organisation (WHO) estimates waterborne diseases as the cause of more than two million deaths and four billion cases of diarrhoea annually worldwide.

In a study, Pure Water Syndrome: Bacteriological Quality Of Sachet- Packed Drinking Water Sold in Nigeria carried out in 2011 and published in the African Journal of Food, Agriculture, Nutrition and Development, it was discovered that 87 per cent of the 108 sachet water samples examined contained Salmonella and/or Escherichia coli, indicative of faecal contamination and inadequate water treatment or no treatment at all. The study also showed that about 65 per cent of the polythene sachets used was not of food-grade quality and imparted polyester taste in the water samples.
The researchers concluded by stating that sachet water samples examined did not meet microbiological standards for drinking water quality.

In an investigation carried out by the National Agency for Food and Drug Administration and Control (NAFDAC) which was established and saddled with the responsibility, among others, of regulation of packaged water and ensuring quality in the production and packaging of water, between 2004 and 2005, it was revealed that some producers of these sachet water indulge in sharp practices such as packaging of untreated water, production under unhygienic conditions, illegal production of unregistered water in unapproved premises, use of non-food grade sachets and release of packaged water for distribution and sale without date marking.

Another research carried out on the Microbiological Analysis of some Vended Sachet Water in Ogbomoso, Nigeria published in the 2009 edition of African Journal of Food Science showed that “all the sachet water samples collected were contaminated with bacteria which included Bacillus spp., Pseudomonas spp., E. aerogenes and P. mirabilis and were present in different proportions.” These micro organisms have been implicated in water related diseases and interestingly, their presence may not be noticed even with the transparent sachets.

In addition to previous health concerns that have been raised, a recent allegation has been put forward that when kept in the sun, sachet water becomes carcinogenic (capable of causing cancer).

However, Dr. Gregory Adewuyi of the Analytical and Environmental Unit, Department of Chemistry, University Of Ibadan, Ibadan, Oyo State, explains that the mere placement of sachet water in the sun, without considering some other factors, is not enough to cause cancer.

“It is true that the exposure of sachet and plastic bottled water to extreme heat can result to a release of certain chemicals from the plastics. This is because some of the components of some of these plastics are not covalently bound into the matrix, so, extreme temperatures can cause them to leach. One of such chemicals is phthalates extract. Phthalates are used as plasticizers but because of their hazardous effects, most developed countries have banned their use in producing plastics. Unfortunately, they are still used in some plastics in the country.

“Bisphenol at some levels are hazardous and can induce carcinogenic conditions. Depending on the composition of the plastic bottle, some of them contain phenol derivatives

“Sadly, the lay man cannot, by observation, know if plastics contain these chemicals. Until the sachet water is subjected to laboratory analysis, one cannot tell which sachet water is carcinogenic or not. This is because you cannot draw inference and conclusion form visual observation; it is highly unscientific,” he said.

He adds that sometimes, exposing sachet water to ultraviolet rays from the sun can be beneficial to deactivating germs. “It depends on the temperature. There are temperatures that are microbiostatic and others that are microbicidal. If the temperature is not enough, it will only deactivate the germs, in which case, the germs can be reactivated. But if favourable conditions arise, they can become active. So, it cannot be a white statement that exposing sachet water to sunlight will kill germs. It is not a scientific statement.

“But keeping sachet water in the sun may not be harmful because ultraviolet rays from the sun can deactivate bacteria in the water, that is, it won’t allow the bacteria multiply,” he said.

Where there could be a health hazard in the relationship between weather condition and sachet water is most likely in the storage. A study on the “Storage Effects on the Quality of Sachet Water Produced within Port Harcourt Metropolis, Nigeria” published in the Jordan Journal of Biological Sciences, it was discovered that “under prolonged storage of packaged water at favourable environmental conditions (temperature values ranging from 27.1 to 28.5ºC, averaging 27.9ºC), total aerobic heterotrophic bacteria can grow to levels that may be harmful to humans and consumption of water containing large numbers of total aerobic heterotrophic bacteria can lead to diseases such as gastroenteritis and mucous membrane infections, particularly in persons whose immune systems are compromised by AIDS, organ transplantation or chemotherapy.”

The researchers stated that from their findings, “sachet water when stored at room temperature for a long period can increase total aerobic heterotrophic bacteria to a level that may be harmful to human health.” They added that “expiry date of sachet water produced in Nigeria should not exceed four weeks from the date of production and the public should be sensitised not to drink sachet water that has exceeded four weeks from the date of manufacture.”

Does this then imply that the average Nigerian does not have a hope of accessing pure water in the country? Dr. Adewuyi states that “There is no pure water in the world. But steps have been taken in most countries to reduce the level of contamination in water, such as salmonella, E.coli, phthalates, e.t.c. It is now the duty of the quality and environmental units of state ministries to collaborate intensively with those in the research field and based on research findings intensify efforts at ensuring that water as well as the containers (sachets or bottles) is as uncontaminated as possible. Their efforts should not be only geared at the production stage but they should also test water weeks after, because it is after weeks of storage that seepage of chemicals can be detected.

Source: Tribune

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