Chemicals and Drugs Found in Nine Common Sewage Sludge Products in First Study of Biosolids by USGS and EPA
This article reports the results of a USGS and EPA sponsored study that was published in 2006. The Kinney study, the first comprehensive examination of sewage sludge, made an important discovery, that the samples of "biosolids were more similar...
February 1, 2008 | Source: U.S. Geological Survey | by
[Editor’s Note: This article reports on the results of the Kinney study published in 2006 (see Reference.) The study, the first comprehensive examination of sewage sludge, made a very
important discovery. The results showed that contrary to the prevailing wisdom the samples of ”
biosolids were more similar than they were different, even though
they were produced by a variety of treatment processes from plants
serving vastly different sized cities and towns.” The treatment processes included anaerobic digestion, aerobic digestion, incineration and composting.]
Biosolids, the treated sludge generated by the treatment
The 25 Chemicals Found in All Nine Biosolids Studied includes compounds that are pharmaceutically and hormonally active, such as
an antimicrobial disinfectant (triclosan), a musk fragrance (tonalide),
an antihistamine (diphenhydramine), and an antiepileptic drug
(carbamazepine).
OCA Toxic Sludge News Pageof sewage at wastewater treatment plants, is something that most people don’t think about as they flush everyday chemicals and drugs down the drain. However, U.S. Geological Survey (USGS) scientists found that biosolids contain relatively high concentrations (hundreds of milligrams per kilogram) of the active ingredients commonly found in a variety of household products and drugs.
Wastewater treatment plants (WWTPs) in the United States generate approximately 7 million dry tons of biosolids each year. Since biosolids are rich in plant nutrients, farmers, landscapers, and homeowners use about 50 percent of the annual production of biosolids as fertilizer for plants. Biosolids must meet standards for nutrient, metal, and pathogen content before it can be used to fertilize plants and to improve the quality of soil. Because a variety of pharmaceuticals and other household chemicals have been found in the wastewater discharged from WWTPs, questions have been raised about the presence of these chemicals in biosolids. To help answer the questions the scientists purchased or obtained nine different commercially or publicly available biosolids and analyzed them for 87 organic chemicals found in cleaners, personal care products, pharmaceuticals, and other products. They found:
* Twenty-five of the chemicals were present in every biosolid sample including compounds that are pharmaceutically and hormonally active, such as an antimicrobial disinfectant (triclosan), a musk fragrance (tonalide), an antihistamine (diphenhydramine), and an antiepileptic drug (carbamazepine).
* Total summed concentrations ranged from 64 to 1,811 milligrams per kilogram (mg/kg or parts-per-million), with many individual contaminants in the hundreds of mg/kg range.
* The biosolids were more similar than they were different, even though they were produced by a variety of treatment processes from plants serving vastly different sized cities and towns. The types of contaminants and their relation to each other did not vary greatly between the biosolids tested.
This is the first comprehensive examination of biosolids, and the results indicate that biosolids have high concentrations of these emerging contaminants compared to treated liquid wastewater effluent. What is not known at present is the transport, fate, and potential ecological effects of these contaminants once biosolids are applied to agricultural fields, garden plots, and landscaped plants and shrubs.