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N.H. Officials Urge Arsenic Tests on Wells



Valley News Staff Writer
Monday, May 21, 2018

Hanover — Public health officials and Dartmouth College researchers are asking New Hampshire residents to test their well water for arsenic, a known carcinogen.

Though the current safety standard set by the Environmental Protection Agency for arsenic, which in New Hampshire primarily comes from the state’s bedrock, is 10 parts per billion, there is no known safe level for human consumption, said Paul Susca, supervisor of the planning unit in the drinking water program for the New Hampshire Department of Environmental Services.

“The only way to know (if you’re being exposed) is to get your well tested,” Susca said in a phone interview on Monday.

Arsenic, a colorless, odorless, tasteless semi-metal, can — at levels above 5 ppb — increase the risk of bladder cancer and reduce IQ in school-aged children, Tracy Punshon, a research assistant professor in Dartmouth College’s Department of Biological Sciences, said in a Monday email.

New Hampshire has the highest rate of bladder cancer cases in the country — 37 percent above the national average — according to the Centers for Disease Control and Prevention. One of the reasons for this high rate is exposure to arsenic through private well water, according to a news release issued by the Department of Health and Human Services earlier this month. A 2014 Dartmouth study found that arsenic in well water is responsible for 830 cases of cancer in the current population, the DHHS release said.

Health effects in pregnant women and their children can include increases in blood pressure, increased risk of gestational diabetes, lower head circumference in infants and a higher risk of upper respiratory tract infections in infants exposed to arsenic in the womb, Punshon said.

“Speaking personally, I care because knowing these risks enables us to protect ourselves and our children from chronic disease,” Punshon said in her email.

As maps from the U.S. Geological Survey have illustrated, the risk of arsenic occurring in groundwater is particularly great in some parts of the state, including Rockingham, Strafford and Hillsborough counties, but all residents are encouraged to test their well water every three years, Susca said.

“The problem with that map (is that) some folks might get the sense it’s a low probability, so (they think), ‘I don’t need to test,’ ” he said.

In fact, he said, arsenic may be present in other parts of the state, including the Upper Valley, though at a lower rate.

Overall, 1 in 5 wells in New Hampshire is believed to be contaminated with arsenic at levels above the EPA’s threshold, according to the U.S. Geological Survey.

The EPA’s standard for arsenic in drinking water — a standard used by those operating public water systems — may not be stringent enough, Susca said.

There is “some concern that 10 ppb is not terribly protective of public health,” he said.

A bill, HB 1592, introduced this session by state Rep. Mindi Messmer, D-Rye, that has passed both the House and Senate would direct NHDES to study the standard.

New Jersey already has lowered its standard to 5 ppb, Susca said.

The standard was last changed to 10 from 50 ppb in 2001, he said.

Changing the standard would mean that public water systems would need to filter out excess arsenic, Susca said.

To monitor arsenic in their drinking water, Susca recommends that New Hampshire residents have their private well water tested every three years. The standard test conducted by the state’s laboratory costs $85, he said. More information about private water testing is available online at des.nh.gov/organization/divisions/water/dwgb/well_testing/index.htm.

Vermont toxicologist Sarah Vose recommends Vermonters test their well water every five years for arsenic and other inorganic compounds. She recommends testing for bacteria annually.

In certain parts of the state, the geology is such that higher levels of arsenic are more commonly found. A few towns in the western part of the state — Castleton, Poultney and Wells — had the highest rate of wells testing above the federal standard, according to a map from the Vermont Department of Health that includes data from 2002 to 2016.

“It does vary,” she said. It’s “important for your health to check your water.”

If a test does reveal arsenic, residents can take steps — such as reverse osmosis and adsorption techniques — to remove it from their water, Susca said. Reverse osmosis uses a synthetic membrane that allows water to go through but leaves arsenic behind, while adsorption captures arsenic with a filter, which contains a type of granular iron oxide.

Beyond drinking water, which is the predominant way people are exposed to arsenic, they also can be exposed through certain foods, such as rice, especially brown rice, Punshon said in her email. Those who consume a lot of rice, perhaps through gluten-free foods, which often rely on rice flours instead of wheat flours, may have higher exposures.

People also can be exposed to arsenic through soils that have been used to grow apple or other fruit trees that were heavily treated with arsenic-based pesticides, she said.

Areas requiring future research include how much arsenic exposure comes from food as opposed to water, how many people regularly test their private well water and whether they conduct regular follow-up checks, and what the mechanism for arsenic toxicity is in the human body, Punshon said.

More information about arsenic is available online at dartmouth.edu/~arsenicandyou/.

Nora Doyle-Burr can be reached at ndoyleburr@vnews.com or 603-727-3213.