Water Pollution, Essay Example

Water quality is increasingly raising concerns as fresh water demand increases worldwide. Advancing technology in industry, medical treatment and agriculture have resulted into   increased concerns for possible adverse ecological and human effects from chemicals in the environment. Pharmaceuticals form part of these chemicals present in the environment. Pharmaceuticals   comprise a wide group of chemicals including, controlled substances, veterinary drugs, over-the-counter drugs, nutritional supplements and diagnostic agents among others (Daughton & Ternes, 1999).

Pharmaceuticals find their way into the environment via several routes. A drug does not disappear after serving its purpose. Both animals and human beings excrete pharmaceuticals as well as their metabolites, which then find their way into the environment via various ways. Untreated and treated domestic sewage is one important source of such compounds in the environment waters. Others include agricultural runoff, manure and bio solids used as fertilizers. Another route of entry is through disposal of expired or unused medications by flushing them down drainages and toilets,   leaching of unused or expired products from landfills following disposal as well as from industrial manufacturing waste streams.

Many of these compounds enter the environment, disperse, and persist to a large extent and as a result they find their way into water bodies via different routes .There is no much known about the extent of occurrence, transport and the final fate of many synthetic organic chemicals especially pharmaceuticals ( Jorgensen & Halling-Sorensen, 2000).

Pharmaceuticals form a small portion of the thousands of synthetic chemicals present in the environment. Due to the small concentrations there has been false impression of potential effects of these compounds. Pharmaceuticals however are designed in such a way that they elicit a biological response even at very low concentrations and it’s this reason that is increasingly causing concern over the effects that medications let loose on the environment may pose. Several pharmaceuticals have been shown to pollute aquatic environments with estrogenic compounds having the most rampant effects on fish. Studies performed in the laboratory have also shown that antidepressants prozac or fluoxetine can slow fish and frog development. In addition carbamazepine an anticonvulsant affects the emergence of mosquito-like insects a common food source for some fish. Reports from The U.S. Geologic Services show that waste pharmaceuticals like steroids, antibiotics, non- prescription and prescription drugs as well as hormones have been found in samples of water collected from streams which are susceptible to contamination from wastewater sources like those found downstream from intense urbanization.  Potential risk to aquatic organisms is of main concern since aquatic organisms may be exposed continually exposed up to multi-generational exposures. Another concern is about the subtle effects on ecological receptors following exposure to low concentrations effect (U.S. Geological Survey 2009).

According to a new report by A Chad A. Kinney a chemistry professor from Colorado State University, pharmaceuticals that travel into the environment through agricultural runoff and soil contaminants do not only pollute the aquatic environment but also are taken up by earthworms living in the soils and consequently end up forming a pathway up the food chain because these earthworms are a source of food for most higher animals. One such medication is antibiotic trimethoprim. Studies also show that crop plants also take up pharmaceuticals. Another study has also traced massive deaths of vultures in Asia from the veterinary use of diclofenac a nonsteroidal anti-inflammatory often used to treat domestic livestock in pakistan and India.  After the death of these animals the vultures feed on them and consequently their death resulting from visceral gout and renal failure.

Scientists are also concerned about the large amounts of antibiotics used for treating livestock as they are creating microbes that are resistant to antibiotic (Hirsch, R. &  Ternes  1998). The route of exposure for humans found to be consumption of drinking water with trace concentrations however studies indicate that such concentrations are too small to cause any appreciable.Researchers are on the lookout for the subtle environmental effects of pharmaceuticals like changes in mating and feeding behaviours as well as antibiotic resistant however finding a handle on the whole problem is not an easy task as they have to consider both the metabolites and products resulting from transformation from natural processes or biodegradation as they may also be harmful (Environmental Science and Technology, v. 36,)

Waste water typically contains a number of pharmaceuticals excreted or flushed which in many times remain biologically active and pose effects to the ecological system especially hormones like oestrogen which appear to affect aquatic life significantly. These drugs and hormones may however be effectively removed by employing additional techniques in addition to the conventional ones. Conventional treatment removes larger particles but when used together with additional techniques, the smaller particles can be removed as well. Such additional techniques include addition of lime prior to filtration, followed by reverse osmosis in which water is forced through a semi permeable membrane which prevent the passage other molecules (U.S. Department of the Interior 2009).

References

Daughton, C.G. & Ternes, T.A., 1999, Pharmaceuticals and personal care products in the environment: Agents of subtle change? Environmental Health Perspectives.

Hirsch, R. &  Ternes (1998). Determination of antibiotics in different water compartments via liquid chromatography-electrospray tandem mass spectrometry: J. Chromatography

Jorgensen, S.E. & Halling-Sorensen B. (2000). Drugs in the environment: Chemosphere, v. 40, p. 691- 699.

Pharmaceuticals, hormones and other organic wastewater contaminants in U.S. streams, 1999-2000–A national reconnaissance: Environmental Science and Technology, v. 36, no. 6, p. 1202-1211.

U.S. Department of the Interior (2009). Developing methods to measure new contaminants in aquatic environment. Retrieved 18 February 2010.Available:
< http://toxics.usgs.gov/highlights/new_methods.html>

U.S. Geological Survey (2009) .USGS Scientists Develop New Method to Measure pharmaceuticals in water. Retrieved: 19 February 2010. Available< http://toxics.usgs.gov/highlights/pharmaceuticals_method.html >