Causes and Effects of Water Contamination
Canada has taken its world-class water treatment system for granted as the rest of the world faces the devastating effects of contaminated drinking supplies. Not only do other nations lack sufficient freshwater, but people are at risk of contracting numerous deadly illnesses each year. Sewage from municipal areas and agricultural runoff are of particular concern, as they are rife with biological pathogens, including E. coli and C. jejunum, among others. Wastewater treatment reduces levels of microbes and bacteria found in sewage, but cannot completely remove them. (Nathanson, 2010) In developing nations, the impact of unsafe water supplies is particularly damaging, resulting in over 480,000 deaths annually, gastrointestinal diseases being a leading cause. (WHO, 2022) A few of the most prominent illnesses include cholera, dysentery and typhoid fever.
Although municipal sewage systems place tight restrictions on permitted levels of contaminants in water, citizens are still at risk of coming in contact with various hazardous microorganisms. Cholera, an infection caused by Vibrio cholerae in contaminated water sources, can be fatal if left untreated. It is characterized by watery diarrhea, vomiting, and dehydration. Although developed countries have the issue under control, countries within Asia and Africa struggle to provide safe drinking water, resulting in 1.3 to 4 million cases per year, and up to 100,000 deaths. (Cholera - Vibrio Cholerae Infection | Cholera | CDC, 2022) Poverty and poor sanitation services also contribute to the high death toll.
Figure 1. Vibrio cholerae bacteria forming biofilm (KNOTT & BLOKESCH, n.d.)
Dysentery is another gastrointestinal disease caused by fecal contamination. It commonly results in diarrhea containing blood or mucus, as a result of inflammation in the intestines. It can be caused by bacteria, such as the bacilli of the genus Shigella, or amoebas. In severe cases, death can result from dehydration or toxins released by bacteria. Amebic dysentery is particularly troublesome due to its chronic nature, which makes it difficult to treat. Recurrences are common, and the stress placed on the large intestines can cause ulcers, while the liver may experience infections. (The Editors of Encyclopaedia Britannica, 2023)
Figure 2. Concentrations of Shigella around the world (Antimicrobial Resistance and Presence of Resistance-conferring Genes in S. Sonnei and S. Flexneri., 2015)
Salmonella, which is typically contracted through untreated food and water, can cause typhoid fever. Aside from obvious symptoms such as fever, one may experience stomach pain and diarrhea. The Salmonella enterica serotype typhi bacteria are capable of causing cell death in the small intestine and bowels, which not only results in intestinal bleeding, but also allows other materials to escape from the digestive tract and into the body. (Typhoid Fever - Symptoms and Causes, 2023) Complications include vomiting, abdominal pain and sepsis, which are infections throughout the body.
Although water treatment falls outside an average citizen’s capabilities, there are actions that can be taken to keep oneself and the community safe. Those with septic tanks or cesspools should perform regular maintenance to avoid any risk of bacterial infections. To ensure the sewage system isn’t overwhelmed, avoid flushing materials that aren’t meant to be flushed, and use appropriate waste disposal systems instead. Personal protective measures such as boiling water or using a filtration system can also reduce the risk of contracting potentially fatal illnesses. By reducing pollution and ensuring that water treatment systems run smoothly, individuals can enjoy safer drinking water as a result.
Figure 3. Contents of a filter (Outdoor Water Filter, n.d.)
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