Lab Matters Fall 2024 | Page 46

APHL 2024 POSTER ABSTRACTS

BIOMONITORING AND CHEMICAL THREATS

APHL Recommendations for Expanding and Improving Perand Poly-alkyl Substances ( PFAS ) Testing

P . Moyer , J . Liebreich , J . Nassif , Association of Public Health Laboratories

Background : Due to growing concerns about PFAS contamination and potential impacts on public and environmental health , multiple laboratories and related programs have initiated PFAS testing and other response activities . This mixture of efforts at the local , state and national level have generated a vast and ever-increasing amount of information . An advantage of this current approach is that it promotes local innovation and allows programs and jurisdictions to prioritize resources to focus on the problems deemed important by their constituencies / citizens . However , identifying a comprehensive set of the most up-to-date information to inform decisions related to policy and practice , is difficult and may result in potential gaps in information or duplication of effort .

Methods : In August 2023 , the Association of Public Health Laboratories ( APHL ) hired a consultant and began a project , APHL Recommendations for Expanding and Improving Per- and Poly-alkyl Substances ( PFAS ) Testing to help coordinate and assist with PFAS activities occurring at environmental and public health laboratories . The intent of the project was to preserve the positive aspects of the current methodologies while moving to standardize and harmonize approaches to increase the generation of and access to PFAS exposure information . One component of the project was a review of current PFAS response activities and related references , including the 2022 National Academies of Science , Engineering and Medicine ( NASEM ) Guidance on PFAS Exposure , Testing and Clinical Follow-Up and the 2024 Agency for Toxic Substances and Disease Registries ( ATSDR ) PFAS Information for Clinicians documents . Additional project information came through online interviews and conference calls with state and federal experts on biomonitoring and PFASrelated activities . Significant input was also obtained at the 2024 National Biomonitoring Meeting held in Honolulu , HI in January 2024 . At this meeting a series of draft recommendations was presented to attendees . This was followed by a series of roundtable discussions intended to identify information gaps and known challenges in PFAS response activities .

Results : The feedback and input obtained through the avenues described above along with an opportunity to meet and discuss this information with the National Biomonitoring Network Steering Committee proved to be valuable and significant . This information has been reviewed , discussed and assimilated into the final report which is the main deliverable for this APHL project .

Conclusion : The culmination of this work is a report focused on a series of steps that can be implemented to help expand and improve response efforts at local , state , regional and national levels to identify and reduce PFAS-related exposures . This report strives to address gaps and challenges through a series of recommendations . The recommendations fall into the following categories : funding investments , quality assurance standardization , testing activity coordination , method and data harmonization and data accessibility . The focus of this report is to address issues specifically related to PFAS testing . However , these compounds serve as a model for investing in and establishing improved laboratory testing practices in general , thus expanding and enhancing the response to environmental contamination and human exposures .

Presenter : Paul Moyer , pfmeoh @ gmail . com

Comparison of Culture-based , qPCR and dPCR Methods for E . coli Detection at Three Milwaukee Beaches

J . Zimmer 1 , S . Siomko 2 , L . Beversdorf 1 , City of Milwaukee Health Department Laboratory 1 , University of Bristol Veterinary School 2

Beach testing plays an important role in public health as contaminated waters can lead to adverse health effects in a community . Escherichia coli is used as a biological fecal indicator marker at three City of Milwaukee beaches to reduce exposure to harmful pathogens associated with fecal pollution . Currently , the Milwaukee Health Department Laboratory ( MHDL ) uses Colilert-18 to determine the prevalence of E . coli , which provides results a minimum of 18 hours after sampling . This delay in results , which could correspond to a delay in beach advisories or closures as public health action , can be avoided by using molecular-based techniques to quantify E . coli DNA in these same samples . Many laboratories have already implemented a molecular approach for beach testing , such as the US Environmental Protection Agency ’ s ( EPA ) Draft Method C qPCR assay . However , newer technologies such as digital PCR ( dPCR ), may provide molecular testing that is less affected by PCR inhibitors and provides absolute quantification as opposed to relative quantification based on a standard curve .

In 2022 and 2023 , MHDL modified Draft Method C for dPCR and compared the results to qPCR and Colilert-18 . In accordance with the EPA ’ s requirement for site-specific alternative methods , we performed an Index of Agreement Analysis among the MPN / 100 mL of the three tests with the following results : 0.9 ( Colilert-18 vs . dPCR ), 0.8 ( Colilert-18 vs . qPCR ) and 0.9 ( dPCR vs . qPCR ). We also reviewed each tests ’ beach action ( i . e . open , advisory , closed ) based on their respective MPN / 100 mL values using Colilert-18 as the reference test . Three percent of the dPCR samples resulted in a false negative and an 8 % were false positives whereas 9 % of the qPCR samples resulted in false negatives and 1 % false positives . These findings indicate that not only is dPCR a suitable method for quantifying E . coli at beaches , but it also outperforms qPCR at Milwaukee beaches by providing more accurate results .

Presenter : Julia Zimmer , jzimmer @ milwaukee . gov

Continuation of Pilot Project Using Lead Isotopes to Determine Sources of Child Lead Poisoning .

C . Danielson , C . Dahman , A . Hawkins , Wisconsin State Laboratory of Hygiene

Due to the adverse effects lead can have on children ’ s brain development , growth , behavior and lifelong health , the Wisconsin Department of Health Services ( DHS ) is currently recommending blood lead testing of all children under the age of five . This is a great step toward identifying cases of lead poisoning in children , however prompt and complete remediation of the exposure source is essential to decreasing the child ’ s blood lead level . In some cases , it can be difficult to determine the primary source of the lead