This Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review synthesized effects of background levels of per- and polyfluorylalkyl substance (PFAS) levels on reproductive health outcomes in the general public: fertility, preterm birth, miscarriage, ovarian health, menstruation, menopause, sperm health, and in utero fetal growth. The inclusion criteria included original research (or primary) studies, human subjects, and investigation of outcomes of interest following non-occupational exposures. It drew from four databases (Web of Science, PubMed, Embase and Health and Environmental Research Online (HERO)) using a standardized search string for all studies published between 1 January 2017 and 13 April 2022. Risk of bias was assessed by two independent reviewers. Data were extracted and reviewed by multiple reviewers. Each study was summarized under its outcome in terms of methodology and results and placed in context, with recommendations for future research. Of 1712 records identified, 30 were eligible, with a total of 27,901 participants (33 datasets, as three studies included multiple outcomes). There was no effect of background levels of PFAS on fertility. There were weakly to moderately increased odds of preterm birth with higher perfluorooctane sulfonic acid (PFOS) levels; the same for miscarriage with perfluorooctanoic acid (PFOA) levels. There was limited yet suggestive evidence for a link between PFAS and early menopause and primary ovarian insufficiency; menstrual cycle characteristics were inconsistent. PFAS moderately increased odds of PCOS- and endometriosis-related infertility, respectively. Sperm motility and DNA health were moderately impaired by multiple PFAS. Fetal growth findings were inconsistent. This review may be used to inform forthcoming drinking water standards and policy initiatives regarding PFAS compounds and drinking water. Future reviews would benefit from more recent studies. Larger studies in these areas are warranted. Future studies should plan large cohorts and open access data availability to capture small effects and serve the public. Funding: Great Lakes Water Authority (Detroit, MI), the Erb Family Foundation through Healthy Urban Waters at Wayne State University (Detroit, MI), and Wayne State University CLEAR Superfund Research (NIH P42ES030991).

Data envelopment analysis is used to compare the relative efficiencies of potable water utilities using the United States Environmental Protection Agency community water system survey data. Three ownership types (private for profit, private not for profit, and public), and two types of supply sources (ground and surface) are compared. Statistically significant results indicating efficiency advantages of certain utility types are found, and clear trends towards certain utility types are identified. The findings indicate that public utilities are most efficient overall, followed by private not-for-profit utilities, with private for-profit utilities being least efficient. Except for a few cases of very large supply demands, utilities employing groundwater sources were generally more efficient than those using surface water sources. A brief investigation into the marginal return on information obtained from using additional measurement variables to measure utility performance is presented. Additional ranking ...

Per‐ and polyfluoroalkyl substances (PFAS) are being studied in all environmental matrices because of their ubiquitous presence and adverse human health impacts. This study conducted a surveillance of 27 water resource recovery facilities throughout the United States and Canada to screen the range of PFAS concentrations in pre‐stabilized sludge and post‐stabilized product. Among the 27 water resource recovery facilities, 82% use anaerobic digestion and the rest use chemical stabilization and/or incineration for sludge stabilization. Forty PFAS compounds were evaluated by US Environmental Protection Agency Method SW846/537.1, and four and nine compounds were reported in the pre‐stabilized sludge and post‐stabilized product, respectively. Concentrations of reported compounds in pre‐stabilized sludge and post‐stabilized product varied from 5 to 33 ng/g dry basis and 2 to 220 ng/g dry basis, respectively. 3‐Perfluoropentylpropanoic acid (5:3 FTCA) and perfluorooctanesulfonic acid (PFOS) were the most frequently observed compounds, and PFAS concentrations in the post‐stabilized products were generally higher than the corresponding pre‐stabilized sludge. Practitioner Points: Among the 40 target PFAS, four were above reporting limit in the pre‐stabilized sludge and nine in the post‐stabilized product. Incineration ash (post‐stabilized product) samples did not have any reportable PFAS. 5:3 FTCA and PFOS were the two frequently observed compounds; concentrations were higher in the post‐stabilized product compared to the pre‐stabilized sludge. PFPeA and PFHxA were the only two short chain perfluoroalkyl carboxylic acids reported. PFOA was reported in only one of the 54 samples evaluated.

Justin D. Brookes, Charles M. Ainger, Carol Howe, John W. Norton Jr and Geoffrey Schlado

Anaerobic digestion (AD) is a key technology for energy recovery in wastewater treatment plants, converting organic matter into methane-rich biogas. However, its efficiency is constrained by slow reaction rates, particularly during hydrolysis and methanogenesis, necessitating large reactor footprints for effective sludge digestion. Alternative AD configurations for process intensification present a promising solution to address these limitations by altering the design and operational setup of the AD process. In this review, key configuration-based AD intensification strategies were systematically analyzed, including recuperative thickening, single-stage thermophilic AD, acid/gas two-stage AD, temperature-phased AD, and multi-stage AD systems. The mechanisms, governing factors, efficiency gains, and scalability of these technologies were critically examined. These configurations demonstrated substantial improvements in methane production rates, process intensification, and the removal of solids and organics. Single-stage thermophilic and cascade AD technologies showed the highest potential for full-scale implementation, supported by successful real-world applications. Conversely, recuperative thickening exhibited promising results at lab and pilot scales but remains limited by its lower technology readiness level. Furthermore, the integration potential of such alternative systems with other intensification technologies was explored, highlighting synergistic opportunities for further optimization. This review provides critical insights into means to intensify AD process through alternative process configurations, offering a comprehensive guide for their application in biogas upgrading. It also identifies key challenges and outlines actionable steps to advance these systems toward widespread adoption in full-scale AD operations.