All about arsenic, how it gets into drinking water, and why it matters

Arsenic is a deadly poison that has been used throughout history to get rid of pesky parents or other relatives who, through stubbornly staying alive, frustrated the ambitions of their heirs. Heck, for a while it was used by all kinds of people for all kinds of reasons – anyone seemed to be fair game. Catherine de Medici, shown below to my right, was someone you wanted to watch closely when she came over for dinner. Luckily for those of us who wish to die a natural death, forensic science has improved since those days and arsenic can now be detected at low levels, making it easier to detect foul play!

So what is this talk about drinking water? Well, in addition to being a poison, arsenic is a natural part of the Earth’s crust – meaning it is a part of soil and rocks. Under some conditions, the arsenic is released from the soil into water. Usually the highest concentrations are found in groundwater – so well water is likely to have higher concentrations of arsenic than river water. The closer health scientists look, the more health problems they seem to find associated with long-term arsenic exposure. Even at the low concentrations found in drinking water in many parts of the world. That’s the reason the US EPA recently lowered the allowable limit of arsenic in drinking water from 50 ppb (that’s parts per billion – a really, really low concentration) to 10 ppb.

If you get your drinking water from a private well, you should have the water tested regularly.  See how to have your water tested. In some places, arsenic is not included in a routine testing, so you might have to ask for it specifically. If the concentration is above 10 ppb, you should treat the water you drink and cook with to remove the arsenic, or drink and cook with bottled water. Some treatment systems are discussed in this web site (see link below) and there are other links so you can learn more about your options. If you’re on a public water supply, your water district must make sure the arsenic concentration is below the allowable limit, and they must also inform consumers if the levels ever get too high, so you should be OK.

This site has been constructed to bring together information about arsenic in drinking water: where it comes from, what it does and how to get rid of it.

See the brochure for information on arsenic in well water from the Maine Bureau of Health.

This web site was created as part of a project supported by the National Science Foundation under Grant No. 0134054.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.