I’ve been a “lurker” on the TCE List serve – a gathering site for those impacted by this old industrial solvent and one of this country’s most important groundwater contaminants. Unfortunately it is an incredibly active list because so many people are affected by this legacy pollutant. Often, I let the emails pile up - shifting them into my TCE folder - in case, one day, I might have something useful to offer the list. But today one email caught my attention.
It began with a posting by Lenny Siegel, Executive Director, Center for Public Environmental Oversight – and list host. The subject line was “PCE in pipes - this is new to me.” If something about these chlorinated solvents is new to Lenny it’s new to a lot of folks, activists and scientists alike, because Lenny really knows his stuff. So I took a look.
According to the Cape Cod Times article posted by Lenny, a study by Boston University epidemiologist Ann Aschengrau, found an association between exposure to PCE (perchlorethylene, or tetrachlorethylene – a solvent most commonly associated with dry cleaning) contaminated drinking water, and an increased risk for birth defects in offspring of Cape Cod women exposed to the water back in the 70's and early 80's.
That PCE was in drinking water wasn’t surprising – it’s a common contaminant in groundwater near old dry cleaning sites . What was surprising was that an old leak, landfill or dry cleaner wasn’t responsible for contamination this time around. The culprit was the municipal drinking water pipes.
Apparently back in the good old days (in this case the 1960’s and '70's) according to the Aschengrau, who was interviewed for the article,
“…water pipes in several towns on the Cape and elsewhere in Massachusetts were purposely sprayed with vinyl plastic and PCE to improve the taste of drinking water.....
Manufacturers wrongly assumed the PCE would disappear during the drying process, but large amounts remained and slowly leached into drinking water in Barnstable, Bourne, Falmouth, Mashpee, Sandwich, Provincetown, Brewster and Chatham, ……Once the PCE contamination was detected, authorities cleared the pipes through a flushing process, saying replacing hundreds of miles of vinyl-coated pipe would be too expensive..”
Reading the chatter on Lenny’s list, I learned that back in the early 1980s Avery Demond, an MIT master’s student studied leaching of PCE from those vinyl lined pipes. Back then Demond wrote that while his focus was on the hydrodynamic factors controlling release of the toxicant, it was “difficult if not impossible” to ignore the social context of the problem. Meaning, people were drinking the contaminated water. As Demond noted, PCE was a common contaminant in drinking water a levels of 1 part-per-billion (ppb) or below. But then a 1976 survey of organic chemicals in water (with a focus on water treatment byproducts) turned up PCE concentrations ranging from 6 ppb to upwards of 1000 ppb in water from a Newport RI state park, warranting a closer look. After seeking potential industrial sources, municipal pipes eventually came under suspicion.
Wrote Demond, early on,
“...the PSWB [water board] tested the liner in May 1968 and contemporary analytical tests and techniques could not find anything undesirable in the water that might have arisen from the water’s contact with the liner. (The sophisticated powerful gas chromatography equipment in general use today was either unavailable or not thought to be needed.) The development of the liner predates the current widespread concern about organics.”
That last statement about sums it up, if you were wondering what they were thinking using pipes recently treated with a solvent combined with a plastic matrix allowing it to leach out over time. They weren't, because they didn't have to. Smell no evil, taste no evil, measure no evil.
Although by the time Demond wrote his thesis, organic solvents were losing their innocence, as residents of Woburn, Massachusetts were realizing the possible linkages between high incidences of childhood leukemia and water contaminated with PCE's chemical cousin, TCE.
Unfortunately for New Englanders, according to Demond, the vinyl-lined asbestos-cement pipes produce by Johns Mansfield Company (of asbestos fame) were used primarily in New England to control alkalinity-related corrosion of the pipes. Over 600 miles of vinyl lined asbestos-cement pipes were laid in Massachusetts, with the majority on Cape Cod. A few years after the leaching problem was identified the company stopped production.
While some pipes were replaced, remediation more often consisted primarily of flushing, until concentrations fell below levels of concern at the time.
Twenty year's later, Aschengrau’s paper in the journal Environmental Health reports finding “large increases in the risk of gastrointestinal defects (particularly oral clefts), neural tube defects (particularly anencephaly) and, modest increases in the risk of genitourinary defects (particularly hypospadias),” and concludes
“The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who identified by independent records.”
For more, check out Aschengrau's paper.