Linking fecal indicator bacteria concentrations in large mixed-use watersheds back to diffuse human sources, such as septic systems, has met limited success. In this study, 64 rivers that drain 84% of Michigan’s Lower Peninsula were sampled under baseflow conditions for Escherichia coli, Bacteroides thetaiotaomicron (a human source-tracking marker), landscape characteristics, and geochemical and hydrologic variables. E. coli and B. thetaiotaomicron were routinely detected in sampled rivers and an E. coli reference level was defined (1.4 log10 most probable number⋅100 mL−1). Using classification and regression tree analysis and demographic estimates of wastewater treatments per watershed, septic systems seem to be the primary driver of fecal bacteria levels. In particular, watersheds with more than 1,621 septic systems exhibited significantly higher concentrations of B. thetaiotaomicron. This information is vital for evaluating water quality and health implications, determining the impacts of septic systems on watersheds, and improving management decisions for locating, constructing, and maintaining on-site wastewater treatment systems. Significance New microbial source-tracking tools can be used to elucidate important nonpoint sources of water quality degradation and potential human health risks at large scales. Pollution arising from septic system discharges is likely more important than previously realized. Identifying these sources and providing reference levels for water quality provides a basis to assess water quality trends and ultimately remediate degraded areas.
Cladophora in the Great Lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. Cladophora provides protection and nutrients, which allow enteric bacteria such as Escherichia coli, enterococci, Shigella, Campylobacter, and Salmonella to persist and potentially regrow in the presence of the algae. As a result of wind and wave action, these microorganisms can detach and be released to surrounding waters and can influence water quality. Enteric bacterial pathogens have been detected in Cladophora mats; E. coli and enterococci may populate to become part of the naturalized microbiota in Cladophora; the high densities of these bacteria may affect water quality, resulting in unnecessary beach closures. The continued use of traditional fecal indicators at beaches with Cladophora presence is inadequate at accurately predicting the presence of fecal contamination. This paper offers a substantial review of available literature to improve the knowledge of Cladophora impacts on water quality, recreational water monitoring, fecal indicator bacteria and microorganisms, and public health and policy.
20 April 2021 in International Journal of Mental Health
Green spaces have been shown to have many benefits for physical and mental health. Recently, blue spaces have been introduced as another field of research and have been suggested to have similar health effects. This scoping review summarized the current state of the knowledge on how blue space exposure (views and visits) affects mental health (depression, anxiety, stress, and associated biomarkers). A keyword search was developed for PubMed, Web of Science, Embase, and PsycINFO. Identified articles were then imported into Rayyan and put through a title review, an abstract review, and finally a full-text review. Five articles were found to have direct relevance to the study. Two articles showed that blue space visits had benefits to general mental health and possibly depression. Two studies investigated blue space views, one showing benefits for general mental health and the other showing benefits for depression. One study showed that both blue space views and visits had positive impacts on mental health and that blue space visits had a stronger effect than merely viewing blue spaces. However, no articles discussed mental health-associated biomarkers. These studies all provide evidence that blue space exposure has a positive impact on mental health, but based on the small number of articles there is not enough evidence to conclude measurable changes in biomarker responses. Further areas of research include man-made/urban blue spaces, other mental health outcomes, virtual reality, and their effects on biomarkers.
Drinking water quality in the United States (US) is among the safest in the world. However, many residents, often in rural areas, rely on unregulated private wells or small municipal utilities for water needs. These utilities may violate the Safe Drinking Water Act contaminant guidelines, often because they lack the required financial resources. Residents may use alternative water sources or install a home water treatment system. Despite increased home water treatment adoption, few studies have examined their use and effectiveness in the US. Our study addresses this knowledge gap by examining home water treatment in a rural Arizona community. Water samples were analyzed for metal(loid)s, and home treatment and demographic data were recorded in 31 homes. Approximately 42% of homes treated their water. Independent of source water quality, residents with higher income (Odds Ratio [OR] = 1.25; 95% Confidence Interval [CI] (1.00–1.64)) and education levels (OR = 1.49; 95%CI (1.12–2.12)) were more likely to treat their water. Some contaminant concentrations were effectively reduced with treatment, while some were not. We conclude that increased educational outreach on contaminant testing and treatment, especially to rural areas with endemic water contamination, would result in a greater public health impact.
This study investigated healthcare workers’ perceptions of hand hygiene practices by comparing personal reports, as assessed by questionnaires, to direct observations of the workers’ hand hygiene practices. The study employed a cross-sectional research design. Observations were made using a 16-item checklist, based on three sources: Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), and Boyce and Pittet’s guidelines of hand hygiene. The checklist was used for both direct-observation and self-reported data collection purposes. Pearson correlation and Multivariate Analysis of Covariance (MANCOVA) were utilized to statistically determine the relationship between healthcare workers’ reports of hand hygiene practices and observed hand hygiene behaviors. The study was conducted in the outpatient examination rooms and emergency departments of three types of hospitals in the Eastern region of Saudi Arabia where Middle East respiratory syndrome coronavirus (MERS-CoV) is endemic and is observed in routine cases and outbreaks. The total sample size included 87 physicians and nurses recruited while on duty during the scheduled observation periods, with each healthcare worker being observed during individual medical examinations with at least three patients. No statistically significant correlations between the healthcare workers’ perceptions of hand hygiene practices and healthcare workers’ actual behaviors were evident. Based on the self-report questionnaires, significant differences were found between physicians’ and nurses’ hand hygiene practices reports. Healthcare workers clearly understand the importance of careful hand hygiene practices, but based on researchers’ observations, the medical personnel failed to properly implement protocol-driven hand hygiene applications. However, the significant differences between physicians’ and nurses’ self-reports suggest further inquiry is needed to fully explore these discrepancies.