Water pollution may affect all of us, directly or indirectly. Paradoxically, it may even affect us when we do not drink it as such. There are several ways by which contaminated water may affect us.
- Consumption of fish and other types of aquatic life. Some water pollutants can bioconcentrate in fish and other types of living organisms, resulting in concentrations much higher (hundreds or even thousands of times higher) than those in the water itself. Thus, by eating polluted fish, humans may get poisoned; this is why it is better to avoid eating a lot of fish unless we have information on where the fish has come from and know its source to be an unpolluted area. However, most, if not all water bodies may be polluted to some extent, which is why it is always safer to consume less fish.
- Consumption of vegetables or fruit irrigated with polluted water - sometimes, irrigation water is brought from farther away as compared to the area where we live; polluted water may thus affect us even when it is not in the immediate vicinity of our home. This is why it is safer to irrigate your vegetables or fruit trees with tap water;
- Bathing in a polluted water body or showering with polluted water – can affect us and our health in various ways, including through:
- skin adsorption
- accidental swallowing
- breathing the vapors of volatile pollutants (such as petroleum products or organic solvents) emanated from water
While many times polluted water bodies may remain unnoticed to our senses, there are several clear signs that a surface water body is polluted, especially when pollution is really high. These signs include (but are not limited to):
The Presence of Algae - The presence of algae, especially in high amounts or in water bodies where they usually are not present, is usually an indication of high amounts of nitrates and phosphates (common fertilizers).
The Presence of a Sheen - The presence of a sheen on water is many times an indication of petroleum products or other chemicals that are less dense than water and thus float on water.
The Presence of Foam - The presence of foam on water may be due to detergents or detergent-like compounds, some of which may be harmful to human health, especially if present in large amounts.
Strange Smells - Any strange or unusual smell of water is a direct result of various pollutants evaporating from the water and thus indicate the presence of water pollution.
Water Coloration - Any unusual water coloration or discoloration may be a result of high amounts of certain chemicals in that water, indicating water pollution.
Dead Fish - The presence of dead fish or any other type of dead aquatic life is probably the clearest and threatening sign that water is highly polluted.
Big water bodies such as the Colorado River may be polluted at levels high enough to pose a potential health threat. Thus, the levels of perchlorate in the Colorado River are high enough to be considered a potential health risk. Perchlorate is not a federally regulated chemical in water, but various states in the U.S. (including California) have adopted their own limits (safe levels) for perchlorate. This chemical may trigger thyroid dysfunction.
Pool water can get polluted too! Never use any chemical treatments in excess. Too much chlorination of pool water may get rid of any infectious microorganisms and pathogens, but may also be responsible for the formation of toxic organic chemicals containing chlorine such as chloroform.
Polluted water may exist without being perceived by any of our senses. This is usually due to a low concentration of chemicals in water (in parts per billion or ppb ranges – which are as little as one to a few drops into an Olympic-size swimming pool!), which are still at levels high enough to potentially cause human harm, especially if exposure over long periods of time occurs. This type of pollution is more problematic than the obvious one (with examples given above) because people may be exposed without knowing it and thus will not take any preventive measures.
Never swim in a pool without showering first (even if it is your own pool). This is because your sweat will get in the pool water and result in the formation of nitrate and nitrate compounds. These compounds are in fact responsible for algae bloom recorded in many pools. However, even if these compounds may not increase to large enough amounts to create an algae problem, they may still be harmful to your health if you swim or get in the pool often. Also, nitrate compounds are highly soluble and have little volatility thus will accumulate and concentrate in pools. The only way to get rid of them is to replace the pool water with a new one.
Any leaves or organic material left in the pool for longer may provide pollutants. These are mostly organic chemicals which are an integral part of various organic matters.
Global warming with increased levels of carbon dioxide also manifests itself by affecting the quality of our waters! Even huge bodies of water, such as oceans, may become acidic due to increased levels of carbon dioxide, which gets into the ocean with precipitation water and is hydrolyzed, forming carbonic acid. This is because oceans absorb about a quarter of the carbon dioxide produced by human activities.
Pollutants from air and soil may end up in the water (with precipitation water), while pollutants from the water may contaminate the soil and air around the polluted water. Thus, there is a natural cycle specific for each pollutant. The mobility of contaminants and their ability to pollute various media (e.g. water, air, soil) is a function of their various properties. For example, the more water soluble pollutants will tend to contaminate the water and spread through water faster than those less water-soluble. The more volatile pollutants will tend to evaporate faster from water into air and then travel via air over long distances.
Tap Water Is Much Safer than most People Realize
This is true in countries with strict environmental regulations, where tap water is checked regularly and reports are made available annually for the public. Bottled water may not be checked regularly and thus it may be riskier than tap water. An even better alternative is to filter the tap water yourself (with home filtering devices). This is also more economical and will save you the effort of carrying tens and hundreds of gallons of bottled water from the store!
Water that Appears Clean Isn't Always Clean
You should never base your judgment on the taste, smell, or the look of water in order to establish or assure yourself that the water is clean. Municipal tap water should, in general, be a safe option in many countries such as the U.S., where there are strict water regulations in place. However, when in doubt, you may test the water using various kits available commercially, or just send it to a specialized lab. The routine water analysis is much less expensive than the potential cost to your health!