Researchers identify potential hazards in biosolid fertilizers
phys.org/news/2024-06-potent…
Among them were bisphenol A (BPA), commonly found in plastics, and carbamazepine, a drug used to treat epilepsy and bipolar disorder.
JUNE 25, 2024
Fertilizers manufactured from the sludgy leftovers of wastewater treatment processes can contain traces of potentially hazardous organic chemicals, according to a new study by Johns Hopkins University researchers.
The research, published in Environmental Science & Technology, provides one of the most comprehensive looks at the chemical composition of so-called biosolids across the country and is the first step toward identifying common chemical contaminants that may need government regulation. The findings could help the U.S. Environmental Protection Agency prioritize which organic compounds to investigate further, the researchers said.
"We've been relatively in the dark when it comes to possible organic hazards in biosolids, and we need to know if there are any smoking guns that we're unaware of," said Carsten Prasse, an assistant professor in the Department of Environmental Health and Engineering who studies environmental contaminants. "Regulators need to know what these types of fertilizers are made of to determine how they can be responsibly used."
Using analytical chemistry techniques capable of identifying thousands of chemicals, Prasse and his team screened 16 samples of biosolids from wastewater treatment facilities in nine U.S. and three Canadian cities. Samples contained traces of pharmaceuticals, industrial chemicals, and a variety of fragrances. Among them were bisphenol A (BPA), commonly found in plastics, and carbamazepine, a drug used to treat epilepsy and bipolar disorder.
"Because there are so many compounds in biosolids, the question we had was how do we triage? How do we find the chemicals that are widespread and could potentially be problematic, that the EPA and other scientists would need to investigate before proposing regulations," Prasse said.
The researchers then created lists of the chemicals found in each sample and compared them to compounds that popped up in multiple places across the country. They identified 92 compounds that were present in 80% or more of the samples.
The researchers then cross-referenced those 92 compounds against the EPA's CompTox Chemical Dashboard—a database that details the properties, hazards, and potential risks of thousands of chemicals. The dashboard helped the team identify which chemicals were most likely to pose threats to human health or the environment.
"We're not saying that these compounds pose a risk right now, because we haven't done a formal risk assessment," said Matthew Newmeyer, a research associate at the Bloomberg School of Public Health and first author on the paper. "We're saying that these have a potential to be problematic and we need more information in order to make sure these biosolids are safe."
Using biosolids can be beneficial, the researchers said. They are rich in nitrogen, phosphorus, and other nutrients that help plants grow. They require less energy to make than synthetic alternatives. And wastewater facilities can sell biosolids to generate revenue to offset treatment costs and reduce waste sent to landfills or incinerators.
More than half of the 3.76 million tons of biosolids produced in the United States in 2022 fertilized agricultural lands, golf courses, and other landscaped areas, according to the EPA. While direct contact with biosolids is likely limited to occupational exposures, the broader population could be exposed to contaminants absorbed by crops grown in such fertilizers, the researchers said.
The team plans to measure the identified compounds in the biosolids and vegetables grown in biosolid-amended soil to determine if their concentration levels warrant concern. The researchers are also investigating risks to farmers, landscapers, and composters who work with biosolids.
Farmers sue EPA over ‘forever chemicals’ in fertilizer
06/07/2024
The agency is evaluating the risks of two types of PFAS in biosolid fertilizer, but the suit aims for quicker action on enforceable regulations.
Five Texas farmers and ranchers are suing EPA over its failure to limit “forever chemicals” in sludge, a problem that they say has killed their animals, jeopardized their health and devalued their land.
The complaint, filed Thursday in the U.S. District Court for the District of Columbia, comes while EPA assesses the risks of two types of PFAS, or per- and polyfluoroalkyl substances, in biosolids, a term for sewage sludge treated to be used as fertilizer.
That process has been “unreasonably delayed,” the complaint says, which asks the court to establish enforceable deadlines by which the agency must promulgate regulations under the Clean Water Act.
Texas farmers claim company sold them PFAS-contaminated sludge that killed livestock
5 Mar 2024
Two ranches also allege biosolids with ‘forever chemicals’ ruined crops, polluted drinking water and left their properties worthless
A Texas county has launched a first-of-its-kind criminal investigation into the waste management giant Synagro over PFAS-contaminated sewage sludge it is selling to Texas farmers as a cheap alternative to fertilizer.
Two small Texas ranches at the center of that case have also filed a federal lawsuit against Synagro, alleging the company knew its sludge was contaminated but still sold it. Sludge spread on a nearby field sickened the farmers, killed livestock, polluted drinking water, contaminated beef later sold to the public and left their properties worthless, the complaint alleges.
The PFAS levels independent testing found on the farm were “shockingly high”, said Kyla Bennett, policy director for the Public Employees for Environmental Responsibility (Peer) non-profit, which is assisting in the analyses.
The farms’ drinking water was found to be contaminated at levels over 13,000 times higher than the federal health advisory for PFOS, one kind of PFAS compound, a Guardian calculation indicates, and affected meat was as much as 250,000 times above safe levels, the lawsuit alleges.
The complaint alleges the families will probably have to abandon their ranches from which they sell livestock.