Whether you're quenching your thirst or prepping a meal, make sure to draw water from the cold tap. Hot water is likely to contain higher levels of lead, says the EPA, because it dissolves the toxic metal in plumbing more quickly than cold water does. If you haven't turned on the faucet for 6 hours or more, let it run cold for a minute before using, the agency advises--and use only water filters bearing a seal from NSF International, a company that certifies products' lead-removing abilities. The average portion of lead exposure in the United States that comes from drinking water is 15%.

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