Recent News

Getting PCBs Out of Schools Explained (in 3 Minutes)

December 16, 2020

ISRP trainee Moala Keshei wins the 2020 University of Iowa Graduate College's Three Minute Thesis (3MT) competition. The 3MT competition challenges graduate students to clearly and concisely articulate complex research to non-specialist audiences.

Moala is a PhD candidate in Civil and Environmental Engineering, studying room-to-room variation and remediation of polychlorinated biphenyls (PCBs).

As a first-generation Cameroonian immigrant raised in urban New Jersey, Moala identifies first hand with the issues in minority-predominant low-income school districts and is determined to bridge the gap in environmental justice experienced by those of low socioeconomic status. The goal of her research is to make PCB remediation cheaper and thus more accessible to minority-predominant, low-income public schools. This is done by studying the PCB concentrations of specific materials in the classroom and then identifying which ones contribute the most PCBs. These are then removed from the classroom. School rooms can be preserved without the need to demolish the entire school.

Passive Samplers Tackle PCB Flux

May 10, 2019

Project 4 researchers have developed a method to measure the movement, or flux, of polychlorinated biphenyls (PCBs) from water to air using passive sampling devices.The team, led by Andres Martinez, Ph.D., and Center Director Keri Hornbuckle, Ph.D., demonstrated that simple and cost-effective passive samplers could be used to overcome this challenge. By improving how PCB flux is measured, researchers can better understand and predict water- and airborne exposures to PCBs in communities living near contaminated waterways.

The team used a dual-sampling system of polyurethane foam passive air (PUF-PAS) and low-density polyethylene (LDPE) water samplers to simultaneously measure PCBs in water and surrounding air. PUF-PAS and LDPE samplers are frequently used to capture and measure persistent organic pollutants like PCBs. Using measured water and air concentrations over time, they were able to calculate the direction and magnitude of PCB flux. According to the authors, passive sampling devices like these can reduce uncertainty and improve the sensitivity and accuracy of analytical methods.

The research was reported in the January 2019 edition of Environmental Pollution.

Above image is courtesy of Andres Martinez.

Releasing Our Data

May 10, 2019

ISRP investigators and the Research Translation Core began placing complete environmental data sets in public data repositories and journals. We have created a list by topic area.

Airborne PCBs:

Project 4 developed a method for measuring fluxes of PCBs from natural waters using air and water passive samplers deployed simultaneously in the Indiana Harbor and Ship Canal.  The complete data set can be found at Included on the website are 15 PCB subsets from this study.

The Analytical Core released a dataset for airborne PCBs and airborne OH-PCBs inside and outside urban and rural U.S. schools. It can be found at this University of Iowa dataset page. This dataset includes indoor and outdoor air mass, concentration, and associated quality control of PCBs and OH-PCBs in two rural schools and four urban schools, the latter near a PCB-contaminated waterway of Lake Michigan in the United States

Project 4 has released the data from a collaborative research project with the Boston University Superfund Research Program studying PCB congener concentrations in New Bedford Harbor. It can be found at The two Superfund Research Programs report the levels of airborne PCB concentrations at 18 locations for three consecutive periods, from July to November of 2015, and one extra period from July to August of 2016 in New Bedford, Fairhaven, Dartmouth, and Acushnet, MA, USA

Previous cycle Project 7 toxicity assessment data from subchronic inhalation exposure to a school air mixture (SAM) of PCBs. This is the first study conducted using environmentally relevant PCB mixtures and concentrations to mimic indoor air from a representative older school.


Project 4 reported the results of the first intensive survey of polychlorinated biphenyls (PCBs) in the surficial sediment of the Indiana Harbor and Ship Canal (IHSC) in East Chicago, IndianaThe data was created by analyzing samples collected in 2010. The complete data set can be found at Included on the website are 12 PCB subsets from this study.

 In addition, ISRP trainees Moala Bannavti and Don McKendry have created a website that helps visualize PCB air, water, and sediment samples collected in East Chicago. The website can be found at


PCBs in Paint

 Project 4 has released the dataset from their study on PCBs and paint colorants. It can be found at This is a dataset for PCB emissions from paint colorants, including file information, methods, investigators, and funding source for the project.


 PCBs in Food

The Analytical Core has released a dataset for PCBs in food. It measured the concentrations of 205 polychlorinated biphenyl (PCB) congeners in 26 food items. It can be found at


Biodegradation of Individual PCBs

Project 5 has developed more than 170 uncultured bacterium clones ribosomal RNA genes, partial sequences for their experiments. The full list can be found at the Iowa Superfund Research Program dataset on the NIEHS website at

In December 2020 Project 5 released a dataset describing biodegradation of individual PCBs by Paraburkholderia xenovorans LB400 in presence and absence of sediment slurry. These experiments were designed to further understand how biodegradation of PCB-degrading microorganisms can be limited by slow mass transfer of PCB molecules from the sediment particles to living cells.


Method for Quantification of OH-PCBs

The Analytical Core has created a dataset for a semi-targeted analytical method for quantification of OH-PCBs in environmental samples. It was released in 2019 and can be found at


Synthesis of PCBs

In July 2020 the Synthesis Core released the Dataset: Fatty Liver and Impaired Hepatic Metabolism Alter the Congener-specific Distribution of Polychlorinated Biphenyls (PCBs) in Mice with A Liver-specific Deletion of Cytochrome P450 Reductase. This excel data sheet summarizes quality assurance /quality control (QA/QC) data, including method detection limits (MDL), recovery rates of spiked ongoing precision and recovery standards (OPR) in both blank solvent and tissue matrix, limits of detection in both mass (ng) and concentration (ng/g tissue) from a study investigating the congener specific tissue distribution in mice exposed orally to Aroclor 1254.

The Synthesis Core also released datasets that were synthesized as analytical standards to study the metabolism of PCB 11. The data sets can be found at:
Authentication of 5-bromo-3-chloro-1,


In March 2020 they also released twelve datasets from previous publications regarding authentication of PCBs:

Authentication of 4-chloro-2-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10293434.v1.

Authentication of 4-chloro-3-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10299302.v1.

Authentication of 4-chloro-2'-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.8194220.v1.

Authentication of 4-chloro-3'-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10295243.v1.

Authentication of 4-chloro-4'-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10299173.v

Authentication of 4-chloro-3',4'-dihydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10295159.v1.

Authentication of 4-chloro-3-fluoro-4'-hydroxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10295207.v1.

Authentication of 4-chloro-2-methoxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10294895.v1.

Authentication of 4-chloro-3-methoxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10295348.v1.

Authentication of 4-chloro-2'-methoxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10293929.v1.

Authentication of 4-chloro-3'-methoxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10299092.v1.

Authentication of 4-chloro-4'-methoxy-biphenyl. 2020. DOI:10.6084/m9.figshare.10299209.v1.







Project 6 Outreach in East Chicago

May 10, 2019

Project 6 Leader Dr. Peter Thorne, staff member Barb Mendenhall, and trainees Ezazul Haque and Tuo Lan attended an EPA meeting in East Chicago, Indiana on April 6, 2019. The EPA debriefed East Chicago residents on its planned cleanup activities for the U.S.S. Lead Superfund site, which encompasses East Chicago’s Calumet neighborhood. During the 2019 season, the EPA plans to remove contaminated soil from properties in both East Calumet and Calumet neighborhoods. Project 6 has been studying airborne PCBs and other contaminant exposures for residents in East Chicago and Columbus Junction since 2010.

During the past several years, it has been meeting regularly with the East Chicago Community Activist Group to hear and address the needs of the community.

Picture courtesy of Kyle Telechan/Post-Tribune.

Human Metabolism of PCBs to OH-PCBs in Human Liver Cells

May 10, 2019

ISRP trainee Eric Uwimana and colleagues from ISRP Synthesis Core, Project 1 and Project 3 investigated the biotransformation of PCB 91 to OH-PCBs by human liver microsomes (HLMs) Human liver microsomes atropselectively metabolize 2,2',3,4',6-pentachlorobiphenyl (PCB 91) to a 1,2-shift product as the major metabolite. The unexpected, preferential formation of a 1,2-shift product and the variability of the OH-PCBs profiles in experiments with individual donor HLMs underline the need for further systematic studies of the atropselective metabolism of PCBs in humans.

Uwimana also examined the metabolism of chiral PCBs and the role of several different P450 enzymes found in the human liver. Uwimana first predicted the likely enzymes involved in producing metabolites of four PCB congeners using ADMET Predictor and MetaDrug. He then confirmed the predictions by incubating the four PCBs with the most likely human P450 isoforms. Results demonstrated that chiral PCBs are metabolized in a congener-specific and atropselective manner to OH-PCBs by CYP2A6, CYP2B6, and CYP2E1 in humans.

PCBs Found in Kitchen Cabinets

May 10, 2019

In a study released in Environmental Science & Technology, Dr. Keri Hornbuckle and trainees Jacob Jahnke and Nick Herkert discovered that kitchen cabinets built within the last five years emit PCBs into the air. The researchers tested sixteen homes with passive air samplers and found PCB- 47, PCB-51, and PCB-68 to account for up to 50% of measured indoor PCBs. They suspect the PCBs are byproducts of sealants used on the cabinets.

The study has garnered extensive coverage. It has been covered by an American Chemical Society press release, Environmental Health News, UPI, US News, and BuzzFeed. In England, it has been covered by the Daily Mail, Times of London, and the Mirror.

The above picture is courtesy of Ablokhin / Getty Images.

PUF Sampling Rates for Any Place in the World

May 10, 2019

The Research Translation Core released the first in a series of web-based applications designed to transfer ISRP research methods and data to researchers, regulators, government, the general public, and other stakeholder communities. It is a method for accurately predicting the sampling volume of passive air samplers deployed anywhere in the world!

This interface was completed as a results of the work done in Herkert et al. (2018). The interface is equipped to run for any dates between Jan. 1, 2010 and Apr. 30, 2018. The samples are collected from twenty-four sites deployed by the Global Atmospheric Passive Sampling (GAPS) network. The model provides information on environmental pollutants at any location around the world.

Isrp Assists in the Community Reporting of Air PCBs

February 05, 2018

The Iowa Superfund Research Program, the Boston University Superfund Program (BUSRP), and three community groups formed a partnership of five project leaders to measure the amount of airborne PCBs in the New Bedford Harbor area. The three community groups were the Toxics Action Center, Alternatives for Community and Environment (ACE), and the Hands Across the River Coalition (HARC).

ACE and HARC developed research questions related to New Bedford Harbor and shared these questions with BUSRP. BUSRP engaged researchers at the Iowa Superfund Research Program, who have a long history of studying lower molecular weight PCBs and their sources. HARC’s role was to recruit air monitor hosts interested in New Bedford Harbor environmental health concerns.

Two workshops were held with monitor hosts so that they could understand the data collected. Monitor hosts worked in pairs with assistance from the Toxic Actions Center and BUSRP to translate the data. The hosts became much more confident in interpreting the data and comparing them to data generated by the EPA. This outreach and cooperation model can be used for other communities impacted by environmental pollutants.

The complete article describing the results of their cooperation can be found in Environmental Science and Pollution Research.

New Study on PCBs in Schools

February 05, 2018

Isrp researchers Dr. Keri Hornbuckle and Dr. Peter Thorne were interviewed by numerous newspapers and National Public Radio after the release of their findings of polychlorinated biphenyls (PCBs) in schools in the journal Environmental Science and Technology.

The study showed that PCBs are present in older schools and that the source of the PCBs is most likely outdated building materials, such as window caulking and light ballasts.

The study, which collected indoor and outdoor air samples at six schools in Iowa and Indiana from 2012 to 2015, is the largest yet to examine airborne PCBs in schools. It shows that while the presence of PCBs can vary from school to school and even from classroom to classroom, children’s exposure rates are roughly the same in rural and urban areas.

It also shows that exposure to PCBs by inhalation may be equal to or higher than exposure through diet, a finding that surprised researchers. Besides PCBs, researchers looked for the first time at OH-PCBs, chemical compounds similar to PCBs, in schools. Although there is still much to learn about OH-PCBs and their potential health risks, some scientists believe they could be more toxic than PCBs.

Following publication of the article, representatives from the EPA and ATSDR and several community groups in the East Chicago area discussed the findings with staff.

Dr. Schnoor Honored at American Chemical Society Meeting

May 24, 2017


Iowa Superfund Research Program Project 5 Leader Dr. Jerry Schnoor was honored at the American Chemical Society Annual Meeting in Orlando on April 2nd and April 3rd. Jerry was honored as having had a profound impact on the field, through leadership in environmental chemistry and modeling, shaping policy, and impacting our educational approaches to our most pressing environmental and health challenges. Jerry's contributions have been impactful in many areas of our field, including groundwater modeling and remediation, air pollution issues and climate change.

The topics that were covered in the two day Tribute to Jerry Schnoor sessions included, but were not limited to, Air modeling: Chemistry and Exposure; Environmental modeling, pollutant transport; Phytoremediation: Plant-mediated Chemistry; Nanoparticle environmental transport and fate. Presenters were from many different universities from across the country and included ISRP Director Dr. Keri Hornbuckle and Project 5 researchers Dr. Tim Mattes from the University of Iowa and Dr. Benoit Van Aken from George Mason University.