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Scientists study ways to reduce PPCPs transferred from soils to food plants

Plant growing in soil

The debate continues: how much risk to human health is the transfer of pharmaceuticals and personal care products (PPCPs) through soils to food plants when biosolids, sewage effluents, and animal wastes are applied to fields? As scientists speculate and study the factors that affect risk, researchers at the Illinois Sustainable Technology Center (ISTC) are finding innovative solutions to remove PPCPs before they contaminate the vegetables and fruits we consume.

PPCPs are the chemicals that make up fragrances, cosmetics, over-the-counter drugs, and veterinary medicines. These chemical residues in the environments are considered emerging contaminants because they are not yet regulated by state and federal agencies.

Organic wastes like biosolids, sewage effluent, and animal waste contain PPCP residues. When these are applied to farm fields, some of the chemicals may degrade, while others may transfer from soils to roots of vegetables and fruits, and then possibly accumulate in edible plant tissues.

Field studies have shown that pharmaceutical concentrations in soils were lower than predicted because PPCPs may degrade in soils, latch on to soil particles, or run off/leach into surface and groundwater. Yet continued and long-term application of PPCP-containing biosolids, animal wastes, and wastewater effluents may increase their concentration levels in plants, according to Wei Zheng, ISTC scientist.

“There has been much argument and debate if PPCPs derived from organic waste application in crop fields can cause risks on public health,” Zheng said. “This issue will become even more at the forefront as the use of biosolids and sewage effluents in crop production systems increases. More studies are necessary because PPCPs vary in their toxicity and physicochemical properties in the environment. In particular, the compounds that are highly persistent and toxic will be a concern.”

Zheng reviewed the literature, summarized the research findings, and made recommendations for future research in a recent article published in Current Pollution Reports.

Factors affecting PPCP transfer

In his review, Zheng reiterated that the factors that have the greatest effect on PPCP transfer are the properties of the PPCPs and soils as well as plant species. Plants grown in sandy soils have higher levels of PPCPs than those grown in high organic matter and clay soils. For certain PPCPs that are destroyed in soils, the process breaks down the original compound into metabolites that may be more toxic and mobile. Metabolites with lower molecular weights could be taken up by plant roots more readily.

Studies have also found that leafy vegetables, such as lettuce and cabbage, tend to have a higher potential to take in PPCPs than root vegetables. Furthermore, certain chemicals accumulate in the roots and have little effect on human health, while others can be transferred to leaves. Further research is needed to develop thresholds for accumulations of PPCPs in food crops when biosolids, effluents, and animal manure are used on fields.

Mitigation efforts

At ISTC, Wei and colleagues are studying several technologies to remove PPCPs, either before they reach the soils or after sewage waste application. The study is being supported by a project funded by the U.S. Department of Agriculture (USDA).

In the project, Wei is studying the feasibility of using inexpensive oils to capture hydrophobic PPCPs from wastewater effluents. The treatment, which would be used at water treatment plants, is especially low cost when applying used cooking oils, such as those from restaurants.

One advantage of this process is that oils remove PPCPs from rural sewage water while leaving behind the nutrients that fertilize crops. After capturing PPCPs, the spent oils can be used as fuel for diesel engines. The process can eliminate the captured contaminants.

Carbon-rich biochar produced from forest and agricultural residues can be used as a filter to absorb PPCPs from sewage water.  Biochar can also be directly applied to soils.

Studies found that the average PPCP concentrations in lettuce leaves decreased by 23 to 55 percent when biochar was used in the soil compared with the soils without biochar. Biochar can also be composted with solid waste to immobilize PPCPs and reduce their transfer in soil-plant systems.

In the USDA project, scientists will conduct laboratory, field, and numerical modeling studies to better understand the transfer of PPCPs to crops when rural sewage effluents are applied to agricultural lands. The results will help federal and state agencies and farmers evaluate their current nutrient management and nontraditional water-use practices, inform science-based regulatory programs, and suggest best management strategies to minimize risks and promote the safe and beneficial use of nontraditional water in agriculture.

Media contact: Wei Zheng, 217-333-7276, weizheng@illinois.edu
news@prairie.illinois.edu

This story originally appeared on the PRI News Blog. Read the original story.

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New project is set to find ways to manage emerging contaminants

Scientists at the Illinois Sustainable Technology Center (ISTC) are tackling the issue of pharmaceutical contaminants from irrigation with rural sewage effluents in a newly funded project.

Collaborating with the Illinois State Water Survey, principal investigator Wei Zheng has begun a three-year study to investigate emerging contaminants, such as pharmaceuticals and personal care products (PPCPs), in fields irrigated with effluents from rural sewage treatment plants and to develop effective strategies to reduce the amount of contaminants transported to surface or groundwater.

Rural sewage effluent has great potential as an alternative to irrigation water, yet there are concerns about possible negative effects. Rural treatment plants are less effective at removing PPCPs compared to municipal wastewater treatment plants. Therefore, the use of effluents might pose a risk to surface and groundwater ecosystems.

Also, field tile drainage systems, which are commonly used in the Midwest, may accelerate the losses of these chemical contaminants from agricultural soils to nearby watersheds. The potential negative effects of using rural sewage effluent to irrigate tile-drained fields are essentially unknown.

In this project, the research team will conduct a series of laboratory, field, and numerical modeling studies to investigate the processes affecting contaminant transport, track the occurrence of PPCPs, and develop two cost-effective control techniques, oil capture and biochar-sorption channels.

The results will help federal and state agencies and farmers evaluate their current nontraditional water-use practices, inform science-based regulatory programs, and suggest best management strategies to minimize risks and promote the safe and beneficial use of nontraditional water in agriculture.

The project is funded by the U.S. Department of Agriculture.

Media contact: Wei Zheng, 217-333-7276, weizheng@illinois.edu, news@prairie.illinois.edu

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ISTC delivers Contaminants of Emerging Concern Report to Illinois General Assembly

In 2018, Illinois’ governor signed House Bill IL-HB5741, which amended the University of Illinois Scientific Surveys Act. The bill directed the Prairie Research Institute (PRI) to conduct a scientific literature review of contaminants of emerging concern in wastewater treatment plant effluent. It also requested that PRI compile a listing of the specific actions recommended by various state and federal agencies to address the environmental or public health concerns associated with these chemicals.

The final report was filed with the General Assembly earlier this week. It reviews the current state of scientific knowledge about contaminants of emerging concern (CEC) in wastewater treatment plants (WWTPs), discusses concentrations of CEC in WWTPs, and reviews existing treatment technologies and U.S. federal and state laws.

The report is available in IDEALS.

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Microplastics may increase the risk of PFAS entering the Lake Michigan food web

This post originally appeared on the Illinois-Indiana Sea Grant web site.

by Irene Miles, Illinois-Indiana Sea Grant

Maggie Oudsema, a research assistant at the Robert B. Annis Water Resources Institute (AWRI), Grand Valley State University and John Scott, Illinois Sustainable Technology Center, lower microplastic samples into Muskegon Lake. (Photo courtesy John Scott)
Maggie Oudsema, a research assistant at the Robert B. Annis Water Resources Institute (AWRI), Grand Valley State University and John Scott, Illinois Sustainable Technology Center, lower microplastic samples into Muskegon Lake. (Photo courtesy John Scott)

Ever-present in our world, it’s not surprising that plastics have been found in waterways virtually everywhere, mostly showing up as microplastics. Another group of contaminants, PFAS (per- and polyfluoroalkyl substances) are, likewise, being detected in the environment all over the world.

All of these contaminants pose concerns on their own, but now research funded by Illinois-Indiana Sea Grant has found that PFAS can stick to microplastic particles in the water, increasing the likelihood that they will end up in the food web.

PFAS are human-made chemicals that are used in many common products such as non-stick cookware, pizza boxes and stain repellent fabric. Qualities that have made them useful—for example, they are very stable and are resistant to water and oil—can contribute to concerns about PFAS. They don’t easily break down in lakes, rivers, wildlife and people. PFAS can have health effects, such as increasing the risk of cancer, decreasing fertility, and impacting growth and learning in infants and children.

Plastics can break down in the environment to microscopic size or they can enter lakes and rivers as microplastics already—for example, as tiny fibers that wash off our clothing. Once in the environment and our waters, microplastics stick around, and like PFAS they do not easily biodegrade.

John Scott, an analytical chemist at the Illinois Sustainable Technology Center, led a team of researchers to understand the extent to which PFAS and other contaminants attach to microplastics in waterways.

His team used three common types of plastic, testing them in the waters of Muskegon Lake, which sits adjacent to Lake Michigan along the Michigan coast. They also did similar testing in a controlled environment using laboratory water.

Microplastic samples were submerged in the nearshore waters of the channel connecting the two lakes and in the middle of Muskegon Lake, for one month and three months in both locations, and in the laboratory for one month.

Rachel Orzechowski, a research assistant at AWRI, Grand Valley State University, sets up microplastics samples to submerge for 1-3 months in Muskegon Lake. (Photo courtesy John Scott)
Rachel Orzechowski, a research assistant at AWRI, Grand Valley State University, sets up microplastics samples to submerge for 1-3 months in Muskegon Lake. (Photo courtesy John Scott)

The researchers found that regardless of location, length of time or type of plastic tested, PFAS in Muskegon Lake adhered to microplastic particles—ranging from .052 nanogram to .87 nanogram of PFAS for each gram of plastic. Interestingly, the amount of PFAS sticking to the microplastic in laboratory water was notably less.

“The difference may be due to associated organic matter or the presence of metals or biofilm, which is a collection of bacteria that grows on microplastic particles in the lake, making the surface easier to stick to,” said Scott. “This would also explain the wide variability that we found in PFAS concentrations on microplastic samples that were identical in substance and treatment. We did not find this degree of variability in the controlled experiments.”

Biofilm is a collection of microorganisms that grow on a variety of surfaces. (Graphic Joel Davenport/Illinois-Indiana Sea Grant)
Biofilm is a collection of microorganisms that grow on a variety of surfaces. (Graphic Joel Davenport/Illinois-Indiana Sea Grant)

Scott points out that the concentration of PFAS they found attached to microplastics in the study is quite low—for perspective, a nanogram is a billionth of a gram—but there is more to the story. “We submerged our samples for limited time, but some studies have estimated that half of microplastics in the environment have been there for 10 to 15 years. And many of these plastic particles in the water are smaller than we used in this study, so with similar mass they have more surface area, which could result in more adsorption.”

Another consideration is that PFAS are only one group of chemicals that can attach to microplastics. Scott said, “We don’t know the implications of what could be a cocktail of contaminants—like PCBs or PAHs—adhering to these particles and ingested by fish or other organisms.”

At the same time, many plastics may already contain additives such as heavy metals, flame retardants and plasticizers that can further exacerbate this issue. “These microplastics-associated pollutants can act synergistically when an organism is exposed to them,” said Scott.

Recent IISG-funded research at Loyola University has shown that fish in three Lake Michigan tributaries are ingesting microplastics. Biologists John Kelly and Tim Hoellein found that 85% of the fish tested contain, on average, 13 pieces of microplastic in their digestive tract.

Does this translate to a level of concern for fish regarding PFAS and other chemicals that may be in these waters and may be attached to microplastics?

“We just don’t know,” said Scott. “We don’t know if PFAS ingested on microplastics stay with the fish, we don’t know at what rate fish ingest microplastics and we don’t know what concentrations in fish are a cause for concern. This project highlights that, in addition to focusing on relevant microplastic concentrations, further studies need to consider environmentally exposed microplastics.”

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Registration is open for the 2020 Emerging Contaminants in the Environment Conference

The 2020 Emerging Contaminants in the Environment Conference (ECEC20) will be on April 21-22, 2020, at the I Hotel and Conference Center in Champaign, IL. Registration is open through April 2 and scholarships for undergraduate students are available.

The conference will feature presentations and posters on the latest in emerging contaminant research, policies, and outreach in the soil, water, and air. There will also be plenty of opportunities for discussion and networking with those interested in all aspects of emerging contaminants in the environment.

Researchers, educators, businesses, government officials, regulatory agencies, policy makers, outreach and extension professionals, environmental groups, members of the general public, and medical, veterinary, and public health professionals are encouraged to submit abstracts and attend the conference.

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ISTC provides science information at public microplastics meeting

ISTC was one of several expert organizations invited to provide information on microplastics at a public meeting hosted by Illinois State Senator Julie Morrison in Highland Park, IL, on August 14, 2019.

Representatives from the Illinois Environmental Council, Shedd Aquarium, and the Alliance for the Great Lakes participated in the event.

ISTC researcher John Scott discussed the current state of knowledge within the scientific community. He also discussed the current ISTC research on the topic.

Members of the public also asked questions and provided comments on the microplastics pollution issue. Two major themes arose from this discussion:

Do microplastics impact human health?
Panel consensus: There is a major gap in knowledge about the impact that microplastics have on human health. There are a few literature review studies available from epidemiology data, but no long-term health studies have been conducted on the impact to humans of exposure to microplastics.

What can we do to stop pollution and clean up microplastics?
Panel consensus:  Shedd Aquarium wants to become a zero waste leader in the community to show businesses and organizations that reducing plastic use is not only possible, but also manageable. ISTC suggested that waste-to-energy processes, such as pyrolysis or gasification, could be a better alternative than landfilling plastic waste. Policies could be implemented to assist in the transition away from plastics, particularly single-use plastics for non-medical/non-disability purposes.

 

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Save the date for the 2020 Emerging Contaminants in the Environment Conference

The 2020 Emerging Contaminants in the Environment Conference (ECEC20) will be on April 21-22, 2020 at the I Hotel and Conference Center in Champaign, IL.

The conference will feature presentations and posters on the latest in emerging contaminant research, policies, and outreach in the soil, water, and air. In addition, there will be plenty of opportunities for discussion and networking with those interested in all aspects of emerging contaminants in the environment.

Upcoming Dates

  • Call for abstracts opens September 4, 2019
  • Registration opens November 2019
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Agricultural pollution associated with antibiotic resistance in bacteria

Pharmaceuticals and other emerging contaminants in the environment are a growing cause for concern. One particular issue is the increase in antibiotic-resistant bacteria.  Agriculture is often noted as a source of excessive antibiotic use.  Over 70% of all antibiotics produced in the U.S. are used in animal agriculture. Overuse can encourage the selection of antibiotic-resistant genes (ARG).

To better understand the relationship between agricultural contamination and ARG abundance over a year-long period, ISTC researchers Wei Zheng and Laurel Dodgen contributed to a project led by Marquette University Professor Krassimira R. Hristova. The study was designed to characterize the emerging chemical contaminants and ARG profiles of 20 surface water locations in an area of Kewaunee County, WI which has an abundance of large-scale farms and where cattle outnumber humans 5 to 1. The team focused primarily on pharmaceuticals and personal care products (PPCPs) and hormones. ISTC’s role was to analyze the PPCPs and hormones in the collected river water and sediment samples to help establish the relationship with ARG.

The results of the study were published in FEMS Microbiology Ecology in 2018. They suggest that Kewaunee County river sediments accumulate contaminants from non-point sources at a higher rate when manure is applied to farmland than when it is not. If these contaminants contain antibiotics, they can either directly increase or co-select for the increase of ARGs in the environment. The study provides a better understanding of how confined animal feeding operations and manure- fertilized farmland impact environmental and human health.

Zheng continues to collaborate with Marquette researchers to determine the chlortetracycline residues in river sediments and water samples and investigate its environmental fate and potential effects. The goal is to evaluate the relationship between the development of chlortetracycline-derived ARG and contaminant residues in the environment.

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Highlights from the 2019 Emerging Contaminants in the Environment conference

The Illinois Sustainable Technology Center and Illinois-Indiana Sea Grant co-hosted the 2019 Emerging Contaminants Conference (ECEC19) on May 21-22 in Champaign, IL. The fourth annual conference featured presentations on the latest in emerging contaminant research, policies, and outreach strategies.

This year’s conference focused on a variety of pollutants in water, soil, and air ranging from pharmaceuticals, viruses, algal toxins and endocrine disruptors to pesticides, flame retardant chemicals, per- and polyfluoroalkyl substances (PFAS), and microplastics.

Scenes from the 2019 Emerging Contaminants in the Environment Conference

The conference speakers included:

  • Susan Richardson from the University of South Carolina, who discussed the state of the art and new discoveries in identification and analysis of emerging contaminants;
  • Thomas Bruton from the Green Science Policy Center, who encouraged attendees to move beyond a traditional risk management approach which deals with individual substances to think about emerging contaminants using a class-based approach. This  method would eliminate the need for testing and regulating each individual contaminant in a particular group of chemicals;
  • Robert Hale from the Virginia Institute of Marine Science, who explained that microplastics and megaplastics on land are just as big a concern as in water and that the many additives plastics make it very difficult to look at the effects they could potentially have on human and animal health.
  • Krista Wigginton from the University of Michigan, who spoke about new detection methods for viruses in drinking water; and
  • Katie Nyquist from the Minnesota Department of Public Health, who discussed how to effectively communicate with different audiences about the issue of emerging contaminants and the importance of getting good science out in the media to combat misinformation.

Other speakers addressed issues related to the public’s perceptions on plastics pollution; increased development of antimicrobial resistant bacteria; modeling contaminants; and new rapid detection methods for PFASs.

Poster session topics included microplastics as vectors for chemical contamination; concerns about nanoparticles in wastewater effluent; child care providers’ knowledge about environmental influences on children’s health; the impacts of emerging contaminants on amphibians and fish; and pharmaceutical disposal practices among veterinarians.

Learn more about the presentations and posters in the conference program booklet. Slides will be available on the conference website within the next two weeks. Details about specific ISTC research on emerging contaminants can be found on our website.