water pollution

Environmental pollution

A polluted river affects the health of the waterway, the health of the organisms living in and around the waterway and eventually the healthy of humans.  The effects of water pollution can range from human disease to economic loss.

            Sediment Pollution effects on Human

Water has been a potential carrier of toxic inorganic and organic materials, non-biodegradable matter and pathogenic microbes which endanger human health and life.  The potable water contaminated with municipal sewage is the root cause of these dangerous diseases in living beings.

Municipal wastes come from the hotel, restaurants, residential areas, refuse, animal waste and human feacal matters etc.  Thus, they induce illness either through the direct consumption of contaminated water or through the food chain. persistent organic pollutants (POP) such as dioxin, PCBS and DDT are chemical substances that persist in the environment and bio-accumulate through the food web; therefore, POPS can also cause sickness and disease in humans, who are at the end of the food chain.

                          Example of water-borne pathogens and diseases and their sources

Name of Micro-organisms           Major Diseases             Major Researchers and Primary Sources


Salmonella typhi                                  Typhoid fever                                  Human feces

Salmonella paratyphi                         Paratyphoid fever                           Human feces

Other salmonella                                  Salmonellosis                               Human and animal feces

Shigell spp                                                Bacillry dysentery                             Human feces

Enteropathogenic E.coli                     Gastroenteritis                                Human feces

Yesinia enterocotica                            Gastroenteritis                             Human and animal feces

Campy lobacter jejuni                           Gastroenteritis                             Human and animal feces

Legionella puenmophila                     Acute respiratory illness                          Thermally enriched H2O

Various mycobacteria                          Pulmonary illness                                        Soil and water

Opportunistic bacteria                           Variable                                                          Natural waters   

Coxsackie viruses A                              Aseptic meningitis                                       Human feces

Coxsackie viruses B                             Aseptic meningitis                                         Human feces

Echo viruses                                            Aseptic meningitis                                          Human feces

Other enteroviruses                             Encephia litis                                                     Human feces

Rota viruses                                             gastroenteritis                                                  Human feces

Adenoviruses                  Upper respiratory and gastrion testinal illness          Human feces

Hepatitis E. virus                                  Infectious hepatitis                                          Human feces

Hepatitis E virus           Infectious hepatitis; miscarriage and death                    Human feces

Balantidium coli                           Balantidosis (dysentery)                                          Human and animal feces

Entamoeba histolytica                    Amoebic dysentery                                             Human and animal feces

Giardia lablia                                       Giardiasis (gastroenteritis)                               Water and animal feces

Naegleria fowlen                     Primary amoebic meningoencephalitis                 Warm water

Ascaus Lumbricoids                                     Ascariosis                                                   Animal and human feces


Sediment Pollution Effect on the Ecosystem

 Sediment body that is more acidic or basic or warmer than usual or that contains toxic metals are harmful to fish waters.  Also chlorinated hydrocarbon insecticides as well as organophosphorus insecticides are poisonous to fish and other aquatics, this is as a result of the fact that most pesticides are broad spectrum toxicants designed to kill living organisms.

Toxic pollutants can also alter the genetic make up of an organism, resulting in either death or extreme deformities studies have found cormorants suffering from cross-billed syndrome at rates 42 percent times the natural occurrence, while terms exhibit birth defects from dioxin, PCBs and furan exposure at 31 times the normal levels.  Other example of deformities include large fish tumors.

Aesthetic Damage

Pollution of rivers is aesthetically awful and sometimes heads to nuisance overgrowth of water weeds (entrophication). entrophication is a natural process that is derived from the greek word “entrophos” meaning well nourished or enriched.  This enrichment leads to other slow processes referred to as natural ageing of lakes or entrophication. Relational Treads of Fresh Water Fish Activity to Turbidity Value This phenomenon, known as entrophication, significantly reduces available (dissolved) oxygen in the water as the algae rots ultimately causing the death of aquatic biota. 

 aesthetic effects by stating that at zero oxygen level anaerobic bacteria obtain oxygen through reduction of nitrates to nitrites.  At the exhaustion of nitrate, they reduce sulphides to hydrogen sulphide still in a bid to obtain oxygen.  This hydrogen sulphide causes foul smell and putrefied taste of water. Algae and diatoms attain a high degree of dominance due to over fertilization.  Algae and noted weeds interfere with the hydroelectric power, clog the filters, retard the water flow and affect the water quality and water works etc.

            Economic Loss

The economy of a community suffers when its river is grossly affected by pollutants.  A turbid river body has a low aesthetic value and will definitely pursue tourists thereby reducing recreational activities. Also trading between communities prevented due to loss of the lives of fishes and other aquatic animals in a polluted river.  Similarly, morbidity rates of individuals in the area will increase.

            Water Quality

Throughout most of the world, the most common contaminants of raw water sources is from human sewage and in particular human faecal pathogens and parasites. Water borne diseases were estimated to cause over 1.8 million deaths each year while about 1.7 billion people lacked proper drinking water. The world health organization sets international standards for drinking water.  It reflects the health of a country.  People and the country’s capacity to collect clean and distribute water to consumers.  According to the United Nations World Health Organization (WHO) more than one billion people in low and middle –income countries lack access to safe water for drinking, personal hygiene and domestic use. These numbers represent more than 20 percent of the world’s people.

 Waste water Treatment

The disposal of waste waters is of wide spread national concern.  Treatment of the waste is required before it can be safely buried, used or released back into local water systems in a treatment plant, the waste is passed through a series of screens, chambers and chemical process to reduce its built and toxicity.  The three general phases of treatment are primary, secondary and tertiary.  During primary treatment, a large percentage of the suspended solids and inorganic materials is removed from the sewage.  The focus of secondary treatment is reducing organic material by accelerating natural biological processes.  Tertiary treatment is necessary when the water will be reused, 99 present of solids are removed and various chemical processes are used to ensure the water is as free from impurity as possible.