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).

This field study evaluates the effectiveness of an optical indicator parameter called Tryptophan-like fluorescence (TLF) combined with other water quality parameters to predict E. coli concentrations. Commercially available multi-parameter sondes measuring TLF were deployed upstream and downstream, of five active combined sewer overflow regulators located within a 1.6-km section of the Lower Rouge River in Michigan, United States. E. coli grab samples were collected during three storms of varying size and across seasons: 3/8/22, 28/4/23 and 14/8/23 (D/M/YY) and analyzed by Colilert-18®. These data were paired with TLF and other parameters measured by the sonde to build algorithms that predict E. coli concentrations. Two sets of algorithms were created. The first algorithm was based on a single storm monitored on 14/8/23, and the algorithm was validated against data collected during the 3/8/22 and 28/4/23 storms. An additional algorithm was created for explorational purposes using the results from all three storms to test the hypothesis that data from additional storms would improve the accuracy of E. coli predictions. The manufacturer retained proprietary ownership of the algorithms, so they are not disclosed in this publication. The lab measured and predicted E. coli concentrations were compared on 1:1 plots and R² values were generated for each location and each storm. The R² values generated from the 14/8/23 algorithm range from 0.5705 to 0.0005. The explorational algorithm based on all three storms resulted in R² values of 0.4953 to 0.0045.