(HealthDay News) -- Depending on where you live, the water that comes from your tap can be just as safe as bottled water.

But in some people, common pollutants found in tap water can pose a greater health hazard. The U.S. Department of Health and Human Services offers this list:

• People with a weakened immune system.
• People with HIV/AIDS.
• People who take steroids.
• People who are being treated for cancer.

Young children are at greater risk of harm from lead that's found in older pipes. To avoid this hazard, use only the cold tap for drinking water, and let it run for a minute if you haven't used the tap in more than six hours.

On the other hand, children will benefit from the cavity-fighting fluoride found in public tap water. Most bottled waters do not contain fluoride.