According to some estimates, every year few millions of Americans are sickened by polluted water. Water pollution involves the pollution of surface waters and/or groundwater which may cause a series of diseases referred to as water pollution diseases. These could have serious health impacts. While we can control (to some extent) the water we drink, the pollution of our water streams may have long-term effects by reducing the “drinkable” water reserves of our planet. Additionally, the common filtration methods for water are not efficient for some of the new emerging contaminants – which are many times not tested for either. Water pollution travels slower than air pollution but still may affect large areas.
Water may commonly be polluted by two main categories of pollutants (dissolved or suspended in water):
- Chemicals – including natural or man-made (xenobiotics) chemicals that gets into a water body (dissolved or dispersed in the water) reaching concentrations of health concern; please note that similar with the case of air pollutants, the presence of such pollutants in water is not always obvious and may not be detected by our senses. Common problematic chemicals getting into water are pesticides, chlorinated solvents, petroleum chemicals, mercury, PCBs, dioxins and other persisting organic pollutants; as well as any of the tens of thousands of chemicals used in industrial processes.
- Living organisms (as long as they are induced by human activity; please note that some waters unaffected by human activity may still be naturally polluted with some of these organisms – in which case, the caused diseases may not be seen as pollution diseases):
- Pathogens – including a variety of living organisms (usually from animal waste) such as various species of viruses, bacteria, fungi and intestinal worms. Their presence in water, many times, remains unnoticed.
- Algae – some types of algae are toxic and may overgrow due to the presence of nitrates and phosphates in runoff water (especially agricultural runoff); such overgrowth is usually referred to as “red tide” or “brown tides”. Their toxin may affect the food chain including fish and birds, and ultimately humans. Oxygen depletion in polluted water is another serious problem responsible for killing fishes. All over the world.
While the most common water pollution diseases involve poisoning episodes affecting the digestive system and human infectious diseases, water pollution may cause a large variety of health diseases including:
- Infectious diseases caused by pathogens (usually microorganisms) from animal fecal origins, of which the most common occur in developing countries involving:
- Typhoid
- Giardiasis
- Amoebiasis
- Ascariasis
- Hookworm
- Diseases caused by polluted beach water including:
- Gastroenteritis
- Dhiarrhea
- Encephalitis
- Stomach craps and aches
- Vomiting
- Hepatitis
- Respiratory infections
- Liver damage and even cancer (due to DNA damage) – caused by a series of chemicals (e.g., chlorinated solvents, MTBE)
- Kidney damage caused by a series of chemicals
- Neurological problems - damage of the nervous system – usually due to the presence of chemicals such as pesticides (i.e., DDT)
- Reproductive and endocrine damage including interrupted sexual development, inability to breed, degraded immune function, decreased fertility and increase in some types of cancers – caused by a series of chemicals including endocrine disruptors – which
- Thyroid system disorders (a common example is exposure through perchlorate which is a chemical contaminating large water bodies such as Colorado River)
- Increased water pollution creates breeding grounds for malaria-carrying mosquitoes killing 1.2-2.7 million people a year
- A series of less serious health effects could be associated by bathing into contaminated water (i.e, polluted beach water) including:
- Rashes
- Ear aches
- Pink eyes
Water pollution can affect us:
- Directly – through consumption or bathing in a polluted stream (that involve consumption of municipal water, as well as bathing in polluted lakes or beach water).
- Indirectly – through the consumption of vegetables irrigated with contaminated water, as well as of fish or other animals that live in the polluted water or consume animals grown in the polluted water. This is many times more dangerous than being directly affected through consumption of water because some pollutants bioaccumulate in fish and living organisms (their concentration in fish could be several orders of magnitude higher than their water concentration). Additionally the toxins from the brown tide are strong and can travel via air affecting homeowners close to the beach.
The most common ways of polluting the water include:
- Waste disposal:
- directly into waste-streams
- in the land from which contaminants may leach into the groundwater below
- Urban and agricultural runoff;
- Animal wastes could also add dangerous pathogens (usually microbial groups, viruses and intestinal parasites) into the water;
- From air via acid rain - water can get polluted with air contaminants (that have sometimes traveled long distances – such as the case of Hg) that reach the land and water via acid rain (during precipitation, air pollutants may get dissolved in the water drops and as a result they may acidify the water which is why the polluted rain water is referred to as “acid rain”).
According to a Cornell University study (available athttp://www.springerlink.com/content/101592/ ) water pollution accounts for 80% of all infectious diseases! According to the same study, unsanitary living conditions account for more than 5 million death a year!
Comments : Little that I knew, I was only aware of the effects that water pollution had on environment. When I began my research on different diseases, I realized how cautious we have to be when we drink water. We drink water on daily bases, and it is a crucial requirement of our body to function properly. Saying that, it is indispensable for us to secure the water to be safe and drinkable.
No comments:
Post a Comment