Research involving Maine children might represent a breakthrough in efforts to determine whether exposure to arsenic in drinking water, even at very low levels, could lead to reduced intelligence, say scientists who conducted the study.

Scientists from Columbia University and the University of New Hampshire recently completed a five-year study of 272 schoolchildren in Maine who had been exposed to arsenic in well water. They found that even at low levels, 5 or more parts per billion, the exposure could correlate to lower intelligence, as much as five to six points on IQ tests.

“Everyone was a little taken aback by that,” said professor Amy Schwartz of the University of New Hampshire, who coordinated the testing of Maine children. “This is a great piece of public health research. People shouldn’t panic, but be informed.”

A Maine health official said it’s estimated that nearly 20 percent of the private wells in the state would test at 5 or more parts of arsenic per billion. The chemical is found naturally in groundwater.

Professor Gail Wasserman of Columbia University, one of the study’s lead researchers, said, “It is the first study to actually show a difference in IQ points in the U.S. based on water arsenic levels. … It is statistically significant.”

She said the study is the first of its kind in the nation, and more research must be done to determine whether the results can be replicated. The results were published in the April 1 edition of the Environmental Health research journal.


School districts in the Augusta area and York County took part in the study, with elementary school students participating.

The study accounted for other factors that could affect intelligence, such as parenting, the mother’s education level and the number of children in the home.

Wendy Brennan’s daughter Carrington, 14, is one of the children who were tested. Brennan said it’s disturbing to think that the water supply she once assumed was safe may be harmful to her daughters or the two grandchildren, ages 2 and 1, who live with her on Wings Mills Road in Mount Vernon.

Brennan said Carrington has been drinking the water her whole life and struggles in math, but she doesn’t know if those things are related.

The filtration system that the family installed cost $800, and replacing the filter costs at least $100 every six months, or more often if they drink more water.

“I worry when we can’t replace the filter as quickly as we should,” Brennan said.


Michelle Keating, a member of the Fayette School Committee, called the test results “scary,” though the well water at her home on Main Street has tested within normal ranges for arsenic. Five or six IQ points seems significant, she said, especially if a child’s IQ is already below average.

“It’s really going to impact how we have to look at educating the children,” she said.

Schwartz said the fixes are relatively easy for homeowners with arsenic in their well water. People can buy filtration systems or simply avoid tap water by drinking bottled water.

The challenge is getting the word out to those who get their drinking water from wells to have their water tested, she said. More than half of all Mainers drink from private wells.

The U.S. Environmental Protection Agency standard for arsenic in drinking water is no more than 10 parts per billion. It’s far too early to tell whether the Maine study will lead to a tightening of the standard.

Wasserman, at Columbia, noted that even small correlations found between lower IQ and lead paint paved the way for a ban on lead paint in the 1970s.


“It proved worrisome enough to justify action and changing standards,” Wasserman said.

Any changes in EPA standards would likely take years, said Andy Smith, the state toxicologist, although the federal government is in the early stages of examining arsenic in drinking water. Arsenic has been linked to cancer.

The EPA standard applies to public drinking water supplies, but there is no federal standard for private wells or requirement for well owners to have them tested.

But Schwartz said people can do their own tests and make their own decisions.

“As a consumer, I know I wouldn’t wait around for a new standard,” she said.

Smith said the good news is that awareness appears to be increasing. A survey showed that the number of people who said they had their wells tested for arsenic increased from 27 percent in 2003 to 42 percent in 2009.


Most real estate transactions involving private wells in Maine include arsenic testing, although it’s not a state law, Smith said. A new $51,000 federal grant will lead to more public education and outreach efforts around the state, he said.

“This study should be yet another reminder that if you haven’t had your well tested yet, to have your well tested,” Smith said.

Rich Abramson, former superintendent of Regional School Unit 38 in Manchester, Mount Vernon, Readfield and Wayne, helped recruit participants for the study in his district. He said it was beneficial for the towns because participants got free water testing, and the study raised awareness about arsenic in well water.

Abramson said he hopes publication of the results, and a news conference to be held in Augusta in late April or early May, will persuade more people to test their water and seek out resources to mitigate any problems.

Joe Lawlor can be contacted at 791-6376 or at:

Twitter: @joelawlorph

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.