Sludge Watch ==> Sludge - Land Application of Hormones -

[Maureen Reilly]

"Basic wastewater treatment removes about 90 percent of estrogenic 
compounds, on average, while secondary treatments can increase this to more 
than 99 percent, according to Samir Khanal, an engineering professor at Iowa 
State University, who studies estrogenic compounds as they move through the 
wastewater treatment system. He says the greatest risk of groundwater 
contamination may not be from sewage effluent but from biosolids–the sewage 
sludge that is removed during sewage treatment and applied to land as 
fertilizer.
“[Estrogenic compounds] physically attach to the biomass,” Khanal explains, 
which is problematic because biosolid treatment removes hormones less 
efficiently. In the United States, about 50 percent of biosolids removed 
during sewage treatment end up being applied to the land as fertilizer, 
according to Khanal. Other studies have raised additional concerns about 
hormones in manure-based fertilizers and feedlot run-off."



Wading in Hormones
Feminized fish: Susceptible victims of a changing aquatic environment or 
harbingers of worse to come?

Posted By Andrea Anderson on August 1st, 2007 in health | environment

Male fish taking on female characteristics. A community plagued by high 
breast cancer rates. Waterways polluted by manure from animal feedlots. 
These phenomena may seem unrelated, but some researchers suspect they share 
a common link: hormone pollution.

Natural hormones and synthetic compounds that mimic them are increasingly 
being detected throughout the environment, especially in waterways. Of 
particular concern are estrogenic compounds—natural and manmade forms of the 
group of hormones that includes estrogen—which can have dramatic effects on 
aquatic animals. Although links to human health problems are much more 
tenuous, concerns are growing.

“We should probably be concerned about what’s in our drinking water as well 
as what we’re dumping into rivers and lakes,” says University of Colorado 
endocrinologist Dave Norris. Late last year, his team made headlines when 
they showed that even low concentrations of estrogenic compounds released 
into rivers through treated water from sewage plants are giving male fish 
female characteristics in rivers near Boulder, Colorado.

The team studied white sucker, a fish species that lives both upstream and 
downstream of the sewage discharge sites. Certain fish species naturally 
undergo a process called intersex, where they switch from male to female, 
but it’s rare in white suckers—under normal conditions.

But in Boulder Creek and the South Platte River, researchers found more 
feminized fish downstream of sewage effluent sites than upstream. According 
to Norris, sewage treatment systems “weren’t designed to remove this stuff” 
from wastewater. His team found that at least two estrogen compounds—a 
natural estrogen and a type of synthetic estrogen found in birth control 
pills—contributed to the feminization. Each compound is potent enough to 
cause changes in fish on its own, but together they have an even greater 
impact.

“Many of these compounds work through the same [biological] mechanism, so 
they can add up,” Norris explains.

The feminized Colorado fish are not an isolated incident. In 2002, following 
large fish kills in tributaries of the Potomac River in West Virginia, 
researchers found fish with numerous abnormalities, including male 
smallmouth bass whose testes contained egg cell precursors. At some test 
sites nearly all smallmouth bass showed intersex, says U.S. Geological 
Survey biologist Doug Chambers. When Chambers led a subsequent study 
(completed this year), his team found many chemicals, including estrogen 
mimics, even in rivers crossing sparsely populated areas of West Virginia.

On some level, the hormone problem is unavoidable. People and animals 
naturally produce and excrete estrogens. Drugs like birth control pills also 
contain estrogens. But the problem is exacerbated when people carelessly 
flush unused drugs and estrogen mimics down the drains.

Estrogen mimics, or “endocrine disruptors” are chemicals that influence the 
body’s endocrine system which is normally controlled by the body’s own 
hormones. These estrogenic compounds can come from unexpected products like 
personal care items, perfumes and detergents, and some plastics. When these 
products are disposed of, the compounds may combine with natural and 
pharmaceutical hormones from human and animal waste to create a potent 
hormone cocktail.

“If it’s causing these problems in fish, we have to assume that there could 
be human health effects.” says Retha Newbold, a biologist with the National 
Institutes of Health, who has been studying estrogenic compounds for more 
than 30 years.

In humans, an excess of natural estrogen has been implicated as a risk 
factor for many conditions, including some reproductive cancers and breast 
cancer. Tests on lab animals suggest that other organ systems and pre-natal 
development may also be affected, says Newbold. There’s less research on the 
effects of man-made estrogenic compounds, but they may pose similar risks.

Nevertheless, not all researchers are willing to make the leap from sewage 
effluent and fish feminization to drinking water and human health. “There 
are no smoking guns in terms of the human health effects from drinking 
water,” says Bruce Brownawell, a Stony Brook University marine biologist. 
“The evidence to date is that it’s much more of an ecological issue.” Like 
Norris, Brownawell focuses his research on how estrogenic compounds affect 
aquatic life.

Brownawell believes that the levels of estrogenic compounds detected in 
drinking water are largely due to false positive measurements and 
over-analysis. He and his team are working to develop advanced mass 
spectrometry techniques to better detect detergents, natural estrogens and 
pharmaceuticals in waterways. He argues that the estrogenic dose an adult 
would get from drinking three liters of the “worst drinking water” every day 
is about one millionth the minimum dose of estrogen given therapeutically. 
“It doesn’t give me much reason for concern,” he says.

Colorado’s Norris agrees that the concentration of any one estrogenic 
pollutant in drinking water is not high enough to affect an adult human. 
“The people who are saying drinking water is safe are correct – by itself,” 
he says. But all together, he speculates, the compounds may have 
unrecognized effects, particularly for developing fetuses.

Basic wastewater treatment removes about 90 percent of estrogenic compounds, 
on average, while secondary treatments can increase this to more than 99 
percent, according to Samir Khanal, an engineering professor at Iowa State 
University, who studies estrogenic compounds as they move through the 
wastewater treatment system. He says the greatest risk of groundwater 
contamination may not be from sewage effluent but from biosolids–the sewage 
sludge that is removed during sewage treatment and applied to land as 
fertilizer.

“[Estrogenic compounds] physically attach to the biomass,” Khanal explains, 
which is problematic because biosolid treatment removes hormones less 
efficiently. In the United States, about 50 percent of biosolids removed 
during sewage treatment end up being applied to the land as fertilizer, 
according to Khanal. Other studies have raised additional concerns about 
hormones in manure-based fertilizers and feedlot run-off.

Regardless of the source of the contaminated biomass, when the land sits 
above a shallow drinking water sources, estrogenic compounds can enter into 
groundwater, adds Khanal.

In rural areas with less comprehensive sewage treatment, the risk of 
groundwater contamination may also increase. For example, researchers from 
Silent Spring, a Massachusetts-based research and advocacy organization 
focused on women’s environmental health risks, are studying a Cape Cod 
community where most residents rely on septic systems in which solids settle 
in septic tanks and liquids filter through the soil.

Women in this community have an elevated breast cancer risk – as much as 20 
percent higher than the average risk for women elsewhere in Massachusetts. 
When preliminary studies ruled out “the usual suspects,” such as an older 
population, higher mammography levels, or family history, researchers 
started looking at possible contamination in the shallow aquifer that 
provides drinking water for the area.

The group did detect estrogens and other wastewater chemicals in groundwater 
samples, but they cannot directly link them to the community’s breast cancer 
problem. “We are very limited in what we know about people’s lifetime 
exposure [to estrogenic compounds],” explains Silent Spring Institute 
executive director Julia Brody.

Norris insists that until we better understand the effects, any excess 
hormone exposure is too much. “It’s best not to get this stuff in there in 
the first place,” he says.

While estrogens from human and animal waste will be difficult, if not 
impossible, to cut, many argue that estrogenic compounds in laundry 
detergents, optical brighteners, and plastics can and should be replaced or 
reduced. “There’s no simple solution. It’s a very complicated problem and it 
involves a multi-billion dollar industry,” Norris says. “The bottom line is 
that we can’t stand around and point fingers at anyone other than 
ourselves.”