The Most Disturbing Chemicals You Might Find in Your Tap Water


The ongoing water crisis in Flint, Michigan -- where lead contamination has created a public health nightmare -- is a stark reminder that getting good water isn't always as simple as turning on your faucet. Even in cities with high-quality tap water, there are bound to be contaminants that don't get filtered out by the treatment process, or are even byproducts of the treatment process itself.

It's useful to be aware of these contaminants, not just to keep you up at night, but because you can often buy filters tailored to your specific concerns. Using the Environmental Working Group's municipal tap water contaminant guide, we pulled out some of the most common contaminants, what they do, and where you're most likely to find them.


Where it's a problem:Flint, Michigan; Baltimore, Maryland; Oakland, California; and Fresno, California.  
What it does:Lead is a heavy metal that can be found in all parts of our environment, including the soil, air, and water. It gets there through corroded plumbing, manufacturing, mining, and burning fossil fuels.

Lead has the undesirable ability to affect nearly every organ and system in the human body, but the main target of lead's toxicity is the central nervous system, and high enough amounts can damage the brain and kidneys -- and can even lead to death. It can also be a factor in miscarriage in women and can damage sperm production in men.


Where it's a problem: Riverside, California, Charlotte, North Carolina, and Silver Spring, Maryland.
What it does: Most bromodichloromethane is formed as a by-product when chlorine is added to our water supply systems to kill bacteria. There have been no studies that document health effects in humans, but in animal studies, high concentrations can cause kidney, liver and brain damage, including cancers of those organs.


Where it's a problem: Columbus, Ohio; Charlotte, North Carolina; and Little Rock, Arkansas.
What it does: It makes your enemies pass out when you sneak up behind them and cover their faces with a chloroform-soaked rag. Kidding! Chloroform may be more widely known as an old-timey anesthetic, but it's also pretty commonly found in water. It forms as a byproduct when chlorine is used to treat water, and ingesting high levels of chloroform can damage your kidneys or liver. The Department of Health and Human Services has determined that there is reasonable suspicion that it can cause cancer.


Where it's a problem: Long Beach, California; Omaha, Nebraska; and Los Angeles, California.
What it does: Yet another old-fashioned poison, arsenic can find its way into your water supply as a result of mining runoff, erosions of natural deposits, emissions from glass and electronics processing, from wood treated with an arsenic compound, and from pesticide use. That's a lot of stuff that produces arsenic, which, yikes. Very high levels can result in death (duh), but low levels can cause nausea and vomiting, a decreased production of blood cells, heart arrhythmia, and blood vessel damage.


Where it's a problem: Pittsburgh, Pennsylvania; Newark, New Jersey; and Pensacola, Florida
What it does: Radium is a substance formed by the breakdown of radioactive elements like uranium. Exposure to radium can cause anemia or cataracts, and has been shown to affect bone health. High levels of the substance have been shown to be a factor in several types of cancer, including bone, liver, and breast. And things didn't end well for Marie Curie.


Where it's a problem: Las Vegas, Nevada; Jacksonville, Florida; and Mesa, Arizona
What it does: Bromoform is another byproduct that occurs when chlorine is added to the water supply, though small amounts are formed naturally by ocean plants. At high enough levels, it can cause sleepiness or dizziness, and at extremely high levels could knock you out or kill you. You don't want to drink too much bromoform, basically.


Where it's a problem: Los Angeles, California
What it does: Tetrachloroethylene, also known as PERC, is a manufactured substance used for dry cleaning and metal degreasing, but hey, sometimes it's in water, too! Long-term exposure can affect your central nervous system, causing changes in mood, memory, attention, vision, and reaction time.

Alpha particles

Where it's a problem: Houston, Texas; Anaheim, California
What it does: Alpha particles are radioactive elements (ionizing radiation) that are often released from mining waste pollutants and other natural sources. Low levels of alpha particles are not known to be hazardous to our health, but high levels can affect your hair, your gastrointestinal system, and your general health. Anything with radiation typically will cause problems, and you really don't want to be drinking it.

Every city's tap water has different sources and treatment methods, so your best bet is to check out the area relevant to you. If you're a real go-getter, you can even request the public records yourself, but it's probably (a lot) easier to buy a good filter.

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Monica Beyer is a health writer who prefers to use a water filter, even though sometimes she can't get the fit quite right on the faucet. Follow her on Twitter: @monicabeyer