River pollution

Pollution is one the largest threats to our rivers. The reduction in river water quality is a clear indicator of the decline in the environmental health of a river basin. The sources of pollution come from domestic and industrial sewerage, effluents from livestock farms, manufacturing and agro-based industries, suspended solids from mining, housing and road construction, logging and clearing of forest and heavy metals from factories. Urbanisation significantly contributes to the increase in water pollution problems, especially in the form of sedimentation, solid waste, rubbish, and organic pollution. Urban development usually removes forests within a basin that results in soil erosion and sedimentation. Inefficient waste disposal systems and lack of proper sanitation facilities lead to waste and sewage ending up in rivers. Rivers contaminated by sewage contain high levels of organic pollutants, and they become breeding grounds for harmful bacteria and viruses that may cause either mass die-offs or reduced resistance to diseases and loss of reproductive ability of fish and other aquatic organisms. Sewage pollution also causes outbreaks of water borne diseases such as cholera, typhoid and hepatitis A that are detrimental to human. Pollutants such as heavy metals, pesticides and herbicides pose health hazards to human beings and aquatic life. Consumption of fish, prawn or cockles that have accumulated heavy metal pollutants result in disturbed reproduction rates and life spans. Pesticide and herbicide contamination may lead to death or chronic long-term illness in humans as well as impair the fertility and development of both humans and aquatic fauna.