ScienceDaily (Aug. 10, 2011) —
People lose the ability to detect the taste of iron in drinking water with advancing age, raising concern that older people may be at risk for an unhealthy over-exposure to iron, Virginia Tech engineers are reporting in results they term “unique.”

The study appears in the American Chemical Society’s journal Environmental Science and Technology on Aug. 10.

Andrea Dietrich, professor of civil and environmental engineering at Virginia Tech, and her colleagues, Susan Mirlohi, of Christiansburg, Va., a Ph.D. student in environmental engineering, and Susan Duncan, professor of food science and technology, point out that the perception of a metallic flavor in water can help people limit exposure to metals such as iron, which occurs naturally in water or from corrosion of iron water-supply pipes. People need less iron after age 50.

“Metallic flavor, caused by the dissolved iron and copper commonly found in groundwater or which may be introduced to tap water by the nation’s corroding infrastructure, has been an issue for drinking water consumers and utilities,” Dietrich said.

More than two million miles of the nation’s infrastructure of water and wastewater pipes is nearing the end of its useful life, but the mostly underground facilities often do not attract much attention because of this “invisibility,” said Sunil Sinha, Virginia Tech associate professor of civil and environmental engineering and a colleague of Dietrich’s. Sinha is directing two new research projects to develop a National Pipeline Infrastructure Database.

Studies also suggest that older people who consume too much iron — especially in dietary supplements and iron-rich foods — may be at increased risk for Alzheimer’s disease and other age-related conditions. Scientists long have known that taste perception fades with age. Dietrich’s group set out to fill in gaps in knowledge about how aging affects perception of a metallic flavor in water.

Their results with 69 volunteers, aged 19 to 84 years, identified a distinctive age-related decline in their ability to taste iron. People over age 50 tended to miss the metallic taste of iron in water, even at levels above the thresholds set by the U. S. Environmental Protection Agency and the World Health Association.

“Our findings are . . . unique in that drinking water is the source of the environmental sensory contaminant and evidence is provided for wide variation in the human population,” the report states. “Whereas our research focused on iron, there are implications for other metals of health concern, most notably copper from copper pipes as our previous research has demonstrated that copper is less flavorful than iron and it is known that copper is also more toxic than iron.”

The scientists acknowledge funding from the Institute for Critical Technology and Applied Science at Virginia Tech.
Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Virginia Tech.
Journal Reference:
Susan Mirlohi, Andrea M. Dietrich, Susan E. Duncan. Age-Associated Variation in Sensory Perception of Iron in Drinking Water and the Potential for Overexposure in the Human Population. Environmental Science & Technology, 2011; 45 (15): 6575 DOI: 10.1021/es200633p

Thank You For Your Support,

State environmental officials last week requested that energy companies disclose where they conduct “fracking”operations and what chemicals they inject into the ground to tap oil deposits. They also were considering whether to launch an independent study to assess effects of the practice.

The administration plans to undertake a statewide “listening” tour for public comment on an extraction technique that until now has drawn the greatest attention in the Rocky Mountain West and Northeast, where the discovery of toxic chemicals in drinking water near fracking operations has sparked calls for moratoriums and more regulation.

Regulators have yet to develop rules or reporting requirements for the procedure in California, the fourth largest oil-producing state in the nation. Only 78 of the tens of thousands of oil field injection wells in California, where fracking might occur, are listed on a national fracking registry.

Though officials maintain that existing laws protect the state’s drinking water, they acknowledge they have little information about the scale or practice of fracking, causing growing anxiety in communities from Culver City to Monterey. The energy industry is touting the potential of the procedure here to tap the largest oil shale formation in the continental United States.

Mark Nechodom, director of the Department of Conservation, sought to assure lawmakers last week that the state was taking the issue seriously.

“If there’s been any impression that [the administration] has dismissed or ignored public concern about fracking, I apologize but it’s simply not true,” he said. “We share the concern.”

Lawmakers were not convinced. At a hearing Wednesday, they blasted the administration’s actions as little more than cosmetic tweaks, saying that regulations are long overdue for a state that is widely considered the birthplace of the modern environmental movement. Separately, they are pushing legislation that would require oil companies to disclose where they employ the procedure, what chemicals they use and how much water they pump. The bill stalled last year after objections by the energy industry.

“What the Legislature clearly has been saying we want is information and regulations,” said Assemblyman Jared Huffman (D-San Rafael). “And we don’t have either.”

The lower house’s subcommittee on resources tabled the administration’s request for an additional 18 positions in the state’s oil and gas agency, noting that 35 positions had already been approved in the last two years, in part to develop fracking regulations. The state’s nonpartisan legislative analyst reported that 13 of those slots remain vacant.

“To kind of just go along and wait for a study…really isn’t acceptable,” said Assemblywoman Betsy Butler (D-Marina del Rey). “There are other states who have prevented fracking from taking place until they have put those regulations into place. So why would California allow this to be happening without regulations?”

Nechodom, a former senior adviser and scientist for the U.S. Department of Agriculture, told lawmakers he was “a bit surprised” that California had no regulations on fracking, a common procedure at wells statewide, when Brown appointed him conservation director in December.