Untreated sewage causes many serious problems to
human health and marine ecosystems. Many human diseases are caused by the bacteria,
viruses, and pathogens introduced to water sources because of the presence of
untreated sewage. These include cholera, typhoid, dysentery, schistosomiasis, chronic
diarrhea, hepatitis A, and intestinal nematode infections. Many of these
diseases can be fatal. It is estimated that 1.5 million deaths per year, most
of which are of young children, are a result of this contamination. It is also
not uncommon for beaches to be temporarily closed because of the surfacing of
pharmaceutical objects, such as needles, and personal care objects on the
shore. These objects would have easily been sifted out had the water gone
through a treatment plant. Untreated sewage does not only pose a threat to
human life. Metals, such as mercury, chromium, arsenic, and lead, as well as
chlorine compounds, are deadly to aquatic species. Decaying organic material
can use up oxygen in the water to the extent where other aquatic life cannot
survive. Large amounts of phosphorous or nitrogen can cause eutrophication. Untreated
sewage discharge is a lethal, yet preventable, problem.
Works
Cited
“How the Sewer System Works.” MWRA Online. (22 February 2012).
Retrieved from http://www.mwra.state.ma.us/03sewer/html/sewhow.htm.
“Untreated Sewage.” Top 10
worst pollution problems. (2008). Retrieved from
http://www.worstpolluted.org/projects_reports/display/63.
“Wastewater Treatment Water Use.” Water Science for Schools. U.S. Geographical Survey. (9 March
2012). Retrieved from http://ga.water.usgs.gov/edu/wuww.html.
No comments:
Post a Comment