It's a hot day. You've been outside working in the yard. You come inside, grab one of those cups that comes free when you order a pizza, and fill it with cool, refreshing tap water. Unfortunately, that water is full of contaminants (and your plastic cup isn't innocent either).
Types of Contaminants:
Your tap water contains varying levels of the following (depending on where you live) (List of contaminants mostly taken from The Complete Organic Pregnancy by Deirdre Dolan and Alexandra Zissu pp. 38-9, all other sources cited below):
Lead:
Lead is a toxic metal occurring naturally on Earth. "Today, the most common sources of lead exposure in the United States are lead-based paint in older homes, contaminated soil, household dust, drinking water, lead crystal, and lead-glazed pottery" (NIEHS on Lead). Lead can make its way into your body by ingestion or inhalation. Children are especially susceptible to lead poisoning because "Children's growing bodies absorb more lead," and "Children's brains and nervous systems are more sensitive to the damaging effects of lead" (see link below). Lead can also cause reproductive problems, high blood pressure and hypertension, nerve disorders, memory and concentration problems, and muscle and joint pain in adults (EPA on Lead).
Chlorine:
"The pure chemical element has the physical form of a diatomic green gas. The name chlorine is derived from chloros, meaning green, referring to the color of the gas. Chlorine gas is two and one half times as heavy as air, has an intensely disagreeable suffocating odor, and is exceedingly poisonous. In its liquid and solid form it is a powerful oxidizing, bleaching, and disinfecting agent" (Chlorine). Chlorine can be inhaled, ingested, or absorbed through the skin. Ingestion of chlorinated water has been linked to artery damage, cancer, and allergic reactions. In addition, chlorine is able to separate from the water under certain conditions: "Taking a warm shower or lounging in a tub filled with hot chlorinated water, one inhales chloroform. Researchers recorded increases in chloroform concentration in bathers’ lungs of about 2.7 ppb [parts per billion] after a 10-minute shower. Worse, warm water causes the skin to act like a sponge; and so one will absorb and inhale more chlorine in a ten-minute shower than by drinking eight glasses of the same water. This irritates the eyes, the sinuses, throat, skin and lungs, dries the hair and scalp, worsening dandruff. It can also weaken immunity" (More on Chlorine).
Heavy Metals:
Arsenic (ranked number one on the Agency for Toxic Substances and Disease Registry's Top 20 List), lead (see above), iron (although necessary for proper body function, taking more than appropriate can result in poisoning, and does in cases of small children taking adult vitamins), aluminum (linked to Alzheimer's disease) (Heavy Metals), chromium, cobalt, copper, selenium, and titanium are all found in tap water (I'm not sure this is a complete list).
Pesticides:
First, take a look at this site just to see the sheer number of pesticides that are registered with the Environmental Protection Agency (EPA): EPA Registered Pesticides. "Some, such as the organophosphates and carbamates, affect the nervous system. Others may irritate the skin or eyes. Some pesticides may be carcinogens. Others may affect the hormone or endocrine system in the body" (EPA on Pesticide Health Effects). They obviously have a wide range of effects, depending on the pesticide you are exposed to. Even from proper usage, all it takes is some rain to wash the pesticides into our water supply (Pesticides and Drinking Water).
Nitrites:
"Nitrate is an inorganic chemical that is highly soluble in water. Major sources of nitrate in drinking water include fertilizers, sewage and animal manure. Most nitrogen containing materials in natural waters tend to be converted to nitrate. Nitrates also occur naturally in the environment, in mineral deposits, soil, seawater, freshwater systems, and the atmosphere... Nitrite changes the normal form of hemoglobin, which carries oxygen in the blood to the rest of the body, into a form called methemoglobin that cannot carry oxygen. High enough concentrations of nitrate in drinking water can result in a temporary blood disorder in infants called methemoglobinemia, commonly called "blue baby syndrome"" (Nitrites/Nitrates). Additonally, long term exposure to nitrites may cause cancer and reproductive/developmental effects.
Microbes:
Well this one's obvious right? This is why chlorine is added to our water, to kill bacteria, viruses, fungi, and protozoa and prevent us from getting sick. Of course, ingesting microbes can lead to any wide number of diseases, although some microbes are beneficial, and certain parasites (although not necessarily microbes) are not killed by chlorine (More on Chlorine (same link as above)).
Asbestos:
"Asbestos is a group of minerals that generally look like separable, long, thin fibers. These fibers are small and can be seen with a microscope. When these fibers are disturbed, causing the fibers to float in the air, they can be easily breathed into the lungs. Scientists have recognized asbestos as a health threat to humans because these fibers can be breathed into the lungs and can cause cancer and other lung diseases" (ATSDR on Asbestos). "Most epidemiologic studies to see if cancer incidence is higher than expected in places with high levels of asbestos in drinking water detected increases in cancer deaths or incidence rates at one or more tissue sites (mostly in the gastrointestinal tract). Some of these increases were statistically significant. However, the magnitudes of increases in cancer incidence tended to be rather small and might be related to other risk factors such as smoking" (More on Asbestos from the ATSDR). Since asbestos is proven to be a carcinogen when inhaled, it follows that it may be a carcinogen when ingested as well.
Sediment:
There are three main ways that sediment can enter water: "installation of a new well," "precipitates from certain dissolved minerals" (a precipitate is a solid formed by a chemical reaction in a liquid), and "continuous entry of fine clay or sand particles from the soil or from poor quality bedrock" (Sediment in Water). The main problem with sediment is that it seems to be just a general word for stuff in the water that makes it look cloudy. It ranges from harmless to dangerous.
Chloroform:
"Chloroform is a clear, colorless, and mobile liquid with a pleasant, sweet odor" (see below). The effects of chloroform are well known in humans, because of its historical use as an anesthetic. Chloroform is associated with cardiovascular depression, liver necrosis and enlargement, psychiatric and neurological symptoms such as hallucinations and moodiness, dizziness, nausea, fatigue, headache, effects on the central nervous system, interaction with ethanol (ingested alcohol), redness, irritation, burning, pain of the eyes and skin. Additionally, "Based on experimental animal studies, IARC [International Agency for Research on Cancer] has concluded that chloroform should be regarded as a cancer risk to humans. One study of people exposed to chloroform in their drinking water showed a correlation between chloroform concentration and rectal and bladder cancer [Hathaway et al. 1991]" (Chloroform and Health according to OSHA).
Radionuclides:
Certain radioactive minerals, radon, and radon gas can all make their way into your tap water. Above certain levels all of these may present a greater risk of developing cancers. Look here for more information on radionuclides: List of Pollutants in Water.
Fluoride:
This is a controversial topic. Some sites claim it's everything from a carcinogen to bad for your teeth and gums, others claim that below a certain dosage there are no adverse affects. Everyone agrees that it is toxic in high amounts and can cause death if too much is ingested. Most agree that it does prevent tooth decay and cavities, although some claim it does not. The medical community seems to agree that 1ppm [part per million] in the drinking water system is optimal for prevention of tooth decay, but one study shows that of water plant operators involved in the study, "Only one-fourth of operators were able to maintain the fluoride concentration to within 0.1 mg/L of the optimal concentration" (PubMed Article on Fluoride). Certain medical studies point to higher rates of bone fractures, certain cancers, or reduced birth rate caused by long-term exposure to fluoridated water, although at different levels of exposure: (Fluoride and Bone Fractures, Fluoride and Uterine Cancer, Fluroide and Osteosarcoma, Fluoride and Birth Rate). In the end, you will have to choose whether you believe it to be a necessary component of your diet and/or drinking water.
Water Filters:
So what can you do about this? Besides problems from drinking tap water, it can damage you in the shower (see above on chlorine absorption), and it gets into the food you boil and in the plants you water (tap water kills some of my plants, and slows the growth of others, which is especially annoying when you are trying to grow food plants). There are many different kinds of water filtration processes. Some of these can be easily installed in your home, others are more costly/difficult to use, and each removes different contaminants, so a combination of filters will lead to the purest result. See this website for more information on the below processes.
Distillation:
Water is boiled and the water vapor is collected and condensed into water by cooling. While this removes contaminants with boiling points higher than 100°C, those contaminants that boil before water are also captured with the water vapor and are not effectively removed.
Ion Exchange:
Water is passed through resins that react with the water, exchanging ions between the water and the resin. While this effectively removes dissolved inorganics, the resin creates a breeding ground for microorganisms, and particles are not effectively removed. Brita filters combine this method with carbon filtration.
Carbon Absorption:
"Activated carbon is created from a variety of carbon-based materials in a high-temperature process that creates a matrix of millions of microscopic pores and crevices. The pores trap microscopic particles and large organic molecules, while the activated surface areas cling to, or adsorb, small organic molecules" (see link above). However, while carbon filters effectively remove dissolved organics, chlorine, and microorganisms (in some cases), they don't remove heavy metals and other dissolved solids. As stated, Brita filters use this method in conjunction with ion exchange.
Microporous Filtration:
These filters are like woven nets of material that block contaminants that are bigger than the holes. While effectively removing solids, this obviously has little effect on dissolved contaminants.
Reverse Osmosis Filtration:
Water is passed through a semi-permeable membrane by hydraulic pressure that separates the water out from its solution (water + the contaminants). This effectively removes 90-99% of contaminants including, dissolved solids, lead and other heavy metals, asbestos, radium, certain dissolved organics, chlorinated pesticides, and heavy VOCs (volatile organic compounds: although part of a solid or liquid product, these easily break off as a gas; basically, they are like fumes: VOCs). This type of filtration is best used in conjunction with a carbon filter to achieve the purest outcome.
Ultraviolet Radiation:
Water is exposed to UV lights which effectively kill the microorganisms in the water. Although a good method of sanitizing, this removes no particles, dissolved or otherwise.
KDF Filtration:
"Kinetic Degradation Fluxion (KDF) is a high-purity copper-zinc formulation that uses a basic chemical process known as redox (oxidation/reduction) to remove chlorine, lead, mercury, iron, and hydrogen sulfide from water supplies. The process also has a mild anti-bacterial, algaecitic, and fungicitic, effect and may reduce the accumulation of lime scale" (KDF Filters). While this is very effective at removing chlorine and metals, it does not remove other contaminants. It does remove the main contaminant that can be absorbed through skin and inhaled when it detaches from the water at high temperatures: chlorine. Since most contaminants in tap water are mainly only a danger if ingested, this is optimal for use in the shower/bath, especially since it is still effective on water at high heats (such as water temperatures one would expect to find in the shower). If you purchase one of these, it is advised not to by a filter that forces the water to travel upwards, as this greatly decreases the water pressure. For a fairly cheap KDF filter that is easy to install (and doesn't leak at all with a little plumbing tape applied around the central grooves where it opens for filter replacement and maintenance) see KDF filter on Amazon.
Buying Water:
While it may be easy to purchase a carbon filter system for your kitchen sink or for storage in your fridge, and installing a KDF filter on your shower is no big deal, as mentioned above, this doesn't really remove all contaminants. Because of this, although I use both of these methods at home (the carbon filtered water is used to boil pasta, veggies, etc., and the KDF filter protects me while I shower), I choose to purchase the water that I drink (I cannot currently afford to buy a reverse osmosis system for my home and have it installed). I buy a brand of water available at my grocery store, and it goes through an activated carbon filter, a micron filter (basically microporous filtration from what I can tell), reverse osmosis filtration, a post carbon filter (just a type of carbon filtration), and exposure to ultraviolet light. The water is stored in a large dispenser at the store. I press a button, and it fills my glass gallon jug with clean water, which I then take home and put in the fridge. Before you run to the store though, here is a little blurb on water that is pre-bottled (and why you shouldn't buy it):
Bottled Water:
First, despite the contaminants in it, the EPA (Environmental Protection Agency) does regulate tap water. However, "The FDA regulates bottled water, and cannot require certified lab testing or violation reporting; bottlers themselves are responsible for testing. Furthermore, FDA doesn't require bottled water companies to disclose where the water came from, how it was treated or what contaminants it contains" (Story of Stuff: Bottled Water (video)). Thus, you're not really getting a better product, anyway. To be exact, one third of bottled water in the U.S. is filtered tap water, including Aquafina and Dasani, Pepsi and Coke products respectively (and who knows what filtration process they use). Second of all, the bottled water industry creates mountains of waste per year, not only from manufacturing plastic bottles made from petroleum with energy created from petroleum and shipped using petroleum, but also from the mountains of waste that are created by bottles and bottles of water that is consumed every day. So, when you go to the grocery store, avoid bottled water, avoid plastic gallon jugs of water, in fact avoid plastic all together. And that brings me to my next point: toxins in plastic.
Look for my next post for details on which plastics are safe for food/water storage (if any), which aren't, and alternatives to plastic storage.
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