High strontium levels found in eastern Wisconsin groundwater.
By Don Behm of the Journal Sentinel
Add naturally occurring strontium to the list of contaminants — along with arsenic, bacteria and nitrates — possibly lurking in the groundwater of eastern Wisconsin and capable of causing health problems for people drinking water from wells, a University of Wisconsin-Green Bay scientist says.
Families with young children using deep wells in eastern Wisconsin should have their drinking water tested at least once for strontium, a metal that dissolves out of bedrock, according to John Luczaj, an associate professor in the department of natural and applied sciences. This is not radioactive strontium, a byproduct of nuclear energy and nuclear weapons testing.
Tests of water from wells in northeastern Wisconsin, primarily in Brown and Outagamie counties, found unhealthful amounts of natural strontium in 73 of 115 samples, or 63%, Luczaj says in a report summarizing the department’s ongoing study of strontium in groundwater in the region. The report was released last week by the University of Wisconsin Water Resources Institute in Madison.
Infants and young children who ingest elevated levels of this metal in well water can develop strontium rickets, a disease that causes bones to be thicker and shorter than normal and that could result in deformities, the Wisconsin Department of Health Services says in a fact sheet.
“Deformities of the long bones in legs, such as bow-leg and knock knee deformities, can cause lifelong problems with walking,” the department says.
Strontium is a threat to children’s health and their future quality of life because the body mistakes it for calcium and packs it into developing bones, making them softer and weaker than normal.
There is not much public discussion of rickets. Because physicians are not required to report cases, there is no information on its prevalence, said Roy Irving, a toxicologist with the department.
Exposure to heavy doses of strontium early in life also can damage tooth enamel and cause mottling — streaking or spotting — of teeth.
The UW-Green Bay study and an unpublished review of water tests done in 2009 in the Town of Lawrence in Brown County confirm a significant strontium problem in eastern Wisconsin’s deep wells, Luczaj said.
Clean Water Testing, a private laboratory in Appleton, worked with Seymour Community High School science teacher Dennis Rohr to collect and analyze the Town of Lawrence water samples. Fully 131 of 298 samples, or 44%, contained unsafe amounts of strontium.
The Town of Lawrence findings prompted Luczaj to collect and test water samples from a larger geographic area.
In the UW-Green Bay study, highest concentrations of dissolved strontium came from wells drawing water from deep sandstone or dolomite below layers of shale in the stacked deck of eastern Wisconsin’s bedrock, Luczaj said. Water from shallower wells in dolomite above the shale, known as the Niagara Escarpment, or other near-surface aquifers did not contain elevated levels of the metal.
The U.S. Environmental Protection Agency has set a lifetime health advisory level for strontium in drinking water at 4 milligrams of the metal per liter of water, or 4 parts per million.
Water containing more than 4 parts per million of strontium should not be used for drinking, in infant formula or as an ingredient in cooking soups and other foods, according to the Wisconsin Department of Health Services. It can be used safely for bathing, dish washing and other household chores.
The UW-Green Bay study found water containing elevated levels of strontium in 48 of 79 water samples collected from Brown County wells, 11 of 19 from Outagamie County wells, and 7 of 8 from Calumet County wells. There were two samples with elevated amounts from Door County and one from Oconto County.
More alarming for Luczaj and the other scientists participating in the study: Tests found water from a handful of wells exceeded the federal short-term health advisory level of 25 milligrams per liter set for children.
Children drinking just one liter per day for more than 10 days of water exceeding 25 parts per million of strontium are at greater risk of rickets.
Six water samples contained more than 25 ppm of dissolved strontium. Four were from Outagamie County, and there was one each in Brown and Calumet counties.
In the Town of Lawrence samples, tests found strontium levels in excess of 25 ppm in 42 samples, or 14%.
Limited testing of wells in eastern Wisconsin over the last 50 years provides evidence of elevated strontium in groundwater extending in an arc from northeastern Wisconsin south through Fond du Lac and Waukesha counties to the Illinois border, Luczaj said.
Water softeners and reverse osmosis filters in residences remove nearly all of the dissolved strontium, Luczaj said. His observation was based on testing of several additional samples of water treated by softeners.
Even so, deep well owners with a home water softening device should test two samples — one from the well pipe before treatment and one from a faucet after treatment — to check if strontium levels are reduced, said Mary Ellen Vollbrecht, the DNR’s groundwater section chief.
This strategy is effective only if all faucets, including one at the kitchen sink, are dispensing water that has gone through the softener, she said. One caution: No distributors of water treatment devices have sought state approval of their devices for strontium removal or reduction.
Strontium-contaminated water has no taste or odor, according to the Department of Health Services’ fact sheet. Testing of a water sample by a state-certified laboratory is the only way to detect elevated levels of the metal in water.
The DNR encourages all well owners to be aware of the aquifer source of their water and to test water annually for coliform bacteria, Vollbrecht said. Well owners should include tests for other possible contaminants when they are detected in their communities.
Read more from Journal Sentinel: http://www.jsonline.com
Follow us: @JournalSentinel on Twitter