(CNN) The water crisis in Flint, Michigan, may have you asking, "Does my home's water contain lead?"

It's possible. The Environmental Protection Agency says between 10% and 20% of our exposure to lead comes from contaminated water. It's even worse for the youngest and most vulnerable: Babies can get between 40% and 60% of their exposure to lead by drinking formula mixed with contaminated water.

Lead "bio-accumulates" in the body, which means it stays and builds up over time, so ongoing exposure, even at extremely low levels, can become toxic. While the EPA says you can't absorb lead through the skin while showering or bathing with lead-contaminated water, you certainly don't want to drink it, cook with it, make baby formula with it or use it to brush your teeth.

How lead enters your home's water supply

Just like in Flint, lead can enter your home when lead plumbing materials, which can include faucets, pipes, fittings and the solder that holds them all together, become corroded and begin to release lead into the water. Corrosion is most likely to happen when water has a high acid or low mineral content and sits inside pipes for several hours, says the EPA.

While homes built before 1986 are the most likely to have lead plumbing, it can be found in newer homes as well. Until two years ago, the legal limit for "lead-free" pipes was up to 8% lead.

As of January 1, 2014, all newly installed water faucets, fixtures, pipes and fittings must meet new lead-free requirements, which reduces the amount of lead allowed to 0.25% . But that doesn't apply to existing fixtures, such as what is found in many older homes and public water suppliers.

Are you at risk?

Here's a guide to assessing whether you're at risk.

Start by calling your municipal water supplier. (If your water comes from a private well, look for information from www.epa.gov/privatewells .) Ask for a copy of their Consumer Confidence Report, which lists levels of contaminants found during tests, which federal law requires be run on a regular basis. Many public suppliers put yearly reports online, so you can also find it yourself by typing your ZIP code into the EPA's web site at www.epa.gov/ccr

You'll want to see lead levels below the EPA's action level of 15 parts per billion.

If you discover a lead reading at or above that level on the report, take action. According to the Centers for Disease Control, you should call your water supplier and ask this question: Does the service pipe at my street (header pipe) have lead in it?

If the answer is yes ...

If the answer is yes, the CDC says to take these steps immediately: Before using any water in your home, run your shower or other high-volume tap on cold -- never warm or hot -- for at least five minutes. Heating water as it comes out of the pipes increases lead levels.

Then run your kitchen tap on cold -- again, never warm or hot -- for an additional two minutes. You can fill clean containers with this water and use it for drinking, cooking, making baby formula and the like. While boiling water might remove other contaminants, it won't remove lead.

Bottled and filtered water

Why not just use bottled water? You can do that, but be sure to check out the quality of the water before you buy. Some bottled waters are nothing more than tap water or have not been tested, says the CDC. It advises researching your brand at NSF International, a nonprofit water certification organization.

You can also filter your water. Again, caution is in order, as not all filtering systems on the market block lead. The NSF lists ratings on three types: reverse osmosis filter systems and distillation . It warns that many popular pitcher-type filters don't meet today's standards for lead reduction, although they may filter other contaminants.

If the answer is no ...

If the answer is no, you could still have lead exposure from the plumbing inside your home. Because lead is odorless and has no taste, the only way you will know if you have lead in your home's tap water is to have it tested.

Testing your home's water

Start with your local water supplier -- some will come to your home and test for free. If that's not an option, you can buy a lead testing kit from home improvement stores to collect the testing samples.

If you do it yourself, be sure to follow directions carefully and only use "first-draw water," the very first water coming out of your pipes after sitting overnight. If your pipes are contaminated, that water will have the most accumulation of toxins.

You'll send the samples off to a laboratory for analysis. The EPA says the most reliable testing is via a state-certified lab, such as those listed on the EPA's web site.

Of course while you wait for test results on your home plumbing, you'll want to protect yourself and your family from any potential lead in your drinking water. The CDC lists instructions at www.cdc.gov/nceh/lead . When the test comes back, you can find information on how to read the results on NSF.

Lead is everywhere

Finding out about lead in your water is only one part of the solution. Lead enters our bodies from many common contaminated sources other than drinking water, such as dust, soil and air. In fact, the EPA says the main source of lead exposure in the United States comes from inhaling dust or eating particles contaminated by paint chips. That's because lead was a common additive in house paint, gasoline and many other materials for years before its toxicity was known.

Children, especially fetuses and infants are the most vulnerable, says the Environmental Protection Agency, because it takes very little lead exposure to damage a child compared with an adult. Low levels of lead exposure are linked to damage to a child's blood cells and nervous system, as well as learning disabilities, poor hearing, impaired growth and more. In fact, the EPA calls lead poisoning the "number one environmental health threat in the U.S. for children ages 6 and younger."

Many experts suggest that parents get their child's lead level tested at ages 1 and 2, and possibly more often, depending on the area of the country. The test is easily done by a pediatrician, or at a local state, county or city department of health.