A comprehensive study by Johns Hopkins University identifies potentially hazardous chemicals in biosolid fertilizers, calling for regulatory scrutiny and safer agricultural practices.
In a pioneering study, researchers at Johns Hopkins University have unveiled potential hazards lurking in fertilizers derived from the byproducts of wastewater treatment. This landmark study, published in the Environmental Science & Technology journal, sheds light on the chemical contamination present in these so-called biosolids, paving the way for more stringent governmental regulations and safety protocols.
Fertilizers crafted from wastewater sludge are known for their nutrient richness, including vital elements like nitrogen and phosphorus. However, they also harbor traces of pharmaceuticals, industrial chemicals, and various fragrances — substances that may pose significant health and environmental risks.
The study’s lead researcher Carsten Prasse, who is an assistant professor in the Department of Environmental Health and Engineering, emphasized the urgency of the matter.
“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,” Prasse said in a news release.
Comprehensive Screening of Biosolid Samples
Prasse and his team employed sophisticated analytical chemistry techniques to scrutinize 16 samples of biosolids from treatment facilities in the United States and Canada. Among the identified contaminants were bisphenol A (BPA), commonly associated with plastics, and carbamazepine, a medication used to manage 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 added. The study successfully identified 92 compounds present in 80% or more of the samples.
Implications for Regulatory Frameworks
To determine the potential risks posed by these compounds, the researchers cross-referenced their findings with the EPA’s CompTox Chemical Dashboard. This tool assesses the properties, hazards and potential risks of thousands of chemicals, helping highlight which substances most urgently require further investigation.
“We’re not saying that these compounds pose a risk right now, because we haven’t done a formal risk assessment. 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,” the study’s first author Matthew Newmeyer, who’s a research associate at the Bloomberg School of Public Health, said in the news release.
The Path Forward
The research underscores the need for meticulous examination and regulated use of biosolids in agriculture, landscaping, and other applications. Despite their nutrient benefits and energy-saving production, the unchecked presence of harmful chemicals cannot be ignored. According to the EPA, over half of the 3.76 million tons of biosolids produced in the United States in 2022 were used to fertilize agricultural lands and other areas, raising concerns about potential exposure risks.
Moving forward, the team plans to assess the concentration levels of the identified compounds in both biosolids and crops cultivated in biosolid-amended soils. They also aim to evaluate the occupational risks faced by individuals handling these materials, including farmers and landscapers.
This research not only alerts us to hidden dangers in common agricultural practices but also sets the stage for developing safer, more responsible methods of utilizing biosolids. As regulators and scientists work together, this study could prove critical in protecting both human health and the environment from unseen chemical threats.