Tests on Fish Raise New Concerns About Estrogen Levels in Drinking Water
Contamination from wastewater-treatment plants and agricultural runoff cited as a concern
Fresh evidence that some New Jersey waterways are being contaminated by estrogens from water-treatment plants and agricultural sources has prompted calls for curbs on development of environmentally sensitive areas and for more research into an issue that may threaten human health.
A study from the United States Geological Survey found that two species of male fish caught at Great Swamp National Wildlife Refuge in Morris County and at Wallkill River in Sussex County contained a high incidence of “intersex” specimens, in which males adopt some female characteristics.
The study, published in mid-December, included the two New Jersey locations in an investigation of “estrogenic endocrine disruption” among smallmouth and largemouth bass in 19 national wildlife refuges across the Northeast.
It found intersex in smallmouth bass in all 19 locations at between 60 percent and 100 percent of those fish captured, while the condition’s prevalence in largemouth bass ranged from zero to 100 percent of the fish of that species. Overall, 85 percent of the male smallmouth bass and 27 percent of the largemouth bass were found with the condition.
Many of the testing locations were near wastewater treatment plants, industrial sites, or sources of agricultural nutrients. In New Jersey, the Wallkill River site was about three miles downstream from a “major” wastewater treatment plant, while at Great Swamp, researchers found evidence that pesticides had previously been stored and used, the report said.
Although evidence of endocrine disruption in fish -- which are commonly used as indicators of aquatic system health -- has been recognized around the world for about the past two decades, the USGS study was the first to look at the issue at national wildlife refuges in the United States, and should form the basis for further investigation, the authors said.
They called the study the “most comprehensive” of intersex severity in the Northeast region so far.
They identified wastewater treatment plants, animal-feeding operations, and crop fields that are treated with manures and herbicides as the main sources of estrogens.
The report said earlier studies in other areas found that the incidence of intersex was positively correlated to the degree of urbanization in a test location.
Jeff Tittel, director of the New Jersey Sierra Club, said the higher occurrence of estrogen contamination in urban areas reflects the construction of wastewater plants that do not treat for the chemicals, and which should not have been permitted in locations that supply public drinking water.
Tittel said state environmental officials made at least four attempts since the 1980s to designate the Wallkill River and the Great Swamp as “Category 1” waterways, which would have protected them from development, but on every occasion, development interests prevailed. That led to the construction of water-treatment plants and the consequent release of estrogen into public water systems, he said.
“Now we’re seeing deformed fish because of all the pharmaceuticals and other chemicals coming from that sewage and septic discharge,” Tittel said in a statement. “This is a direct result of the government caving to developers and special interests instead of doing their job and protecting clean water.”
Larry Hajna, a spokesman for the Department of Environmental Protection, said the endocrine disruption found at the two New Jersey locations was no different from that found at the 17 other sites studied, or to many other locations around the world.
“The issue is not about one river or one wildlife refuge,” Hajna said. “It’s about our use of chemicals, and whether benefits outweigh risks, and what can be done to address this.”
One of the contributors to the problem is birth-control medication which contains the estrogen that can affect the gender of male fish, Hajna said.
He said the DEP is working with other state and local agencies to urge people not to flush birth-control pills down the toilet where the estrogen will find its way into public water systems because treatment plants are not equipped to remove the chemicals.
Despite the concern raised by environmentalists, one of the authors of the USGS study said there’s no clear evidence that intersex in fish has implications for human health.
“It’s hard to make that leap,” said Luke Iwanowicz, a biologist who contributed to the USGS report. Although it’s possible that estrogens could enter public drinking water through untreated sources, it’s unclear whether they would do so at harmful levels, he said.
Iwanowicz cited a 2009 study published in the journal Environmental Health Perspectives, which concluded that estrogen in drinking water was not causing adverse effects in U.S. residents, including in sensitive populations such as young children.
But he argued that endocrine-disrupting chemicals are “likely” present in other waters around the state, and urged authorities to take a proactive approach to the issue rather than “waiting for all the answers to come in.” He said the treatment of water with activated carbon would “adequately remove the estrogens we know about.”
Daniel J. Van Abs, a water-quality specialist and associate research professor at Rutgers University, said there’s no scientific consensus on whether human health is threatened by estrogen in drinking water, but he said some scientists are concerned.
“The human health effects seem more controversial in the science community, with some saying ‘yes,’ and others saying ‘maybe but we aren’t sure yet,’” Van Abs said. “I haven’t seen anyone recently saying ‘no possible effects’ which itself is an indicator.”
He called estrogen in drinking water “a very legitimate issue” for research, public discussion, and policy making, and predicted the current concern will lead eventually to new requirements on water-treatment plants. (Van Abs is a regular contributor to NJ Spotlight.)
For anglers, the clearest response to the latest report would be to limit consumption of the named fish, said Hajna, even though most practice catch-and-release fishing rather than eating what they catch.
For the two bass species, the state recommends not eating more than one meal a week, and high-risk populations such as infants and women of child-bearing age should limit their intake to one meal per month.