Sludge Watch ==> What goes down the drain then goes out to pasture via toxic sludge - Cornell

[Maureen Reilly]

What goes down the drain, from ibuprofen to soaps, gets turned out to 
pasture via toxic sludge, researchers warn

What goes down the drain -- detergents, personal-care products and discarded 
and excreted medications -- may be out of sight and out of mind, but they 
are not, unfortunately, out of this world.


Significant amounts of toxic chemicals from households persist in the 
environment because they end up in sewage sludge. Though pathogens are 
removed in wastewater treatment plants, no treatment is required to address 
some of the most abundant chemical contaminants that originate in the home. 
So sludge and sludge-rich composts, often containing toxic chemicals, are 
commonly applied to farmland, parks, forests and yards.

Take ibuprofen (its many trade names include Advil and Motrin), for example, 
the third most consumed drug in the world. Wastewater treatment plants 
remove 60 to 90 percent of it, but that's not enough, warns a Cornell 
researcher.

"Given the volume that is consumed, a lot still goes out to the 
environment," says Anthony G. Hay, Cornell associate professor of 
microbiology and director of Cornell's Institute for Comparative and 
Environmental Toxicology. He studies how ibuprofen and other chemicals 
present in sewage sludge are degraded by microorganisms.

"Even low concentrations of ibuprofen have been found to affect the way fish 
spawn, so we don't want it accumulating in the environment," says Hay. 
"Understanding the biological fate is very important for being able to 
predict the potential for toxicity of compounds. In the case of ibuprofen, 
we were able to show that it can be degraded to nontoxic intermediates."

Since legislation prohibits dumping sewage sludge in the ocean, most of it 
in this country is applied to soil for its nutrients and to improve the 
physical properties of the soil, which is often cheaper than landfill or 
incineration.

"However, there are no requirements in the U.S. to test for or remediate 
organic pollutants in sewage sludges, and sludges contain a wide variety of 
these contaminants that conventional treatment does not eliminate," adds 
Ellen Z. Harrison, who served as director of Cornell's Waste Management 
Institute for many years until her recently announced retirement.

Gardeners may unknowingly use sludge-based products, such as free compost, 
because labeling is not mandated. Some products even use the term "organic" 
on their labels, says Harrison.

To make matters even more complex, Hay adds, "Most wastewater treatment 
plants were designed to target industrial pollutants. There are no 
requirements for monitoring chemicals from personal-care products, 
pharmaceutical compounds or antibiotics. We are interested in knowing what 
compounds are out there and if biodegradation is making these things less 
toxic or more toxic."

While looking at sludge, Hay's research team found high levels of compounds 
commonly used in detergents such as alkylphenol ethoxylates that "get more 
toxic as they degrade, becoming persistent compounds that mimic estrogen," 
says Hay. "The concentrations being reported in the environment are below 
levels of concern for most humans but are high enough to affect fish 
populations by changing sex ratios, resulting in fewer males. The question 
is, what is the long-term effect on populations? We don't really know."

Working with graduate student Abbie Wise Porter, Hay found alkylphenol in 
sludges from Syracuse, Cortland, Ithaca and Cayuga Heights at levels that 
were five times higher than most other places that had been studied. This 
suggested that the sludges had about 15-40 times more estrogen activity than 
dairy cow manure, which is considered to have high estrogen levels due to 
lactating cows, says Hay.

In addition, Porter found triclosan, a widely used biocide (used to kill 
bacteria), in all of the sludges at quite high concentrations. "Triclosan is 
coming from the antibacterial hand soaps, deodorants, toothpastes and many 
other personal-care products," says Hay. "There are more and more reports of 
triclosan in environmental samples ... in fish, and in high concentrations 
in breast milk. Triclosan is not all that effective in these products, but 
it is still being marketed to the public to quell their fears about 
microbes. Unfortunately, triclosan inhibits our ability to eliminate other 
pollutants from our body so it may be doing more harm than good."

So what are consumers to do?

"Not buying anti-bacterial hands soaps would be a good first step since 
regular soaps are just as effective," says Hay. "With respect to the other 
pollutants we detected, people can select fragrance-free products when 
possible and look for products that are labeled as biodegradable."

Harrison adds that, at the legislative level, banning the use of certain 
toxic chemicals such as the most toxic brominated flame retardant -- which 
is banned in California -- would be appropriate.

Also, people should find out where the sludge from their local treatment 
plants goes, and make sure it is not used at schools or parks, says 
Harrison. "When they obtain compost or soil amendments for their yards, they 
should find out whether they contain sewage sludge. And of course, they 
should try to use products that don't contain toxic chemicals and should not 
flush unwanted chemicals or pharmaceuticals down the drain."

More suggestions about environmentally friendly products can be found at 
http://www.fingerlakesbuygreen.org/ .

Source: Cornell University

http://www.physorg.com/news120927003.html