Potential Sources Of Contamination Research Articles

From Sea Water to Salt Crystals: An Onsite Investigation of Microplastics in a Conventional Sea Salt Farming System.

This study investigated microplastic (MP) contamination in conventional sea salt farming systems. Various crude sea salt samples (n = 22) that were traditionally produced were collected from salt farms and local vendors. Salt water (n = 15), macroalgae (n = 6), and clay of pond floors (n = 6) were collected from ponds subjected to different production (stabilization, evaporation, and concentration and crystallization concentration) processes. All samples were analyzed for MP abundance and characteristics. The potential sources of MP contamination in the salt were also investigated. The mean abundance of MPs in the salt water and clay of pond floor increased progressively throughout the production process and reached its highest level in the concentration and crystallization ponds (7400 MP particles/m3 in salt water and 19,336 MP particles/m2 in the clay of the pond floor). A maximum of 26,500 MP particles/kg of macroalgal material indicated the potential sink of MPs on the surface of the algae. Approximately 34-2377 MP particles/kg salt were found in the crude sea salt samples. However, the mean abundance (378 MP particles/kg of salt) indicated nonsignificant impacts of different harvesting processes on MP contamination. Most MP size distributions, shapes and polymer types in the salts were similar to those found in the salt water, macroalgae and clay of the pond floor. Approximately 99% of the MPs were fragments that were suspected to be decomposed from larger plastic debris and plastic machinery and tools used at the salt farm. Similar patterns of polymer distribution, in which PP > PE > PET > PS, were found for all samples studied.

Fish Diversity and Water Quality in Munroe Island, Kollam District, Kerala

Munroe Island, located in the Kollam district of Kerala, is renowned for its rich biodiversity and picturesque landscapes. The present study aimed to assess the fish diversity and water quality in the Munroe Island region of Kollam District, Kerala. The ichthyofaunal survey conducted in the area (3 sites) revealed the presence of 23 fish species belonging to 18 families, indicating a diverse fish community in the region. However, threat status assessment using IUCN criteria identified several species as vulnerable or near threatened to anthropogenic pressures. The analysis of physico-chemical parameters of water quality (from 10 sites) highlighted various factors influencing ecosystem dynamics, including temperature fluctuations, pH levels, dissolved oxygen concentrations, and levels of organic pollutants, BOD and COD. Additionally, the presence of ions such as chloride, sulphate, and nitrate suggested potential sources of contamination and pollution due to anthropogenic activities. These findings emphasize the importance of integrated conservation and management strategies to preserve the ecological integrity of Munroe Island’s aquatic ecosystems and ensure the long-term sustainability of fish populations.

Development of Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Pseudomonas aeruginosa multi-species in vitro dry surface biofilm models: Insights into resilience and persistence in low-moisture environments

Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Pseudomonas aeruginosa can persist as dry surface biofilms (DSB) and survive desiccation for prolonged periods of time. This could serve as potential sources of contamination in low-moisture food (LMF) processing environments. The objectives of this study were to develop in vitro mono-and mix-culture DSB models to better understand pathogen survival under dehydrated conditions as DSB. Mono-and mix-culture wet surface biofilms (WSB) of S. enterica ser. Typhimurium ATCC 14028, L. monocytogenes FSL R8-5318, and P. aeruginosa ATCC 15442 were developed following EPA MLB SOP MB-19 protocol on borosilicate glass coupons using a CDC® biofilm reactor. WSB were harvested and dried for 24, 48, and 72 h at 21 °C to form DSB. Mean log10 CFU/cm2 were calculated at each desiccation time point and compared to control (WSB) using LSM of PROC GLM to fit linear models (P = 0.05). Approximately 8.8 ± 1.7, 7.1 ± 1.1, 6.9 ± 0.6, and 6.3 ± 0.8 mean log10 CFU/coupon were recovered from mono-culture Salmonella DSB at 0, 24, 48, and 72 h, respectively. Overall, Salmonella mean log10 densities were limited when co-cultured with P. aeruginosa although there were no significant differences in Salmonella density over desiccation time points. Mean log10 CFU/coupon for L. monocytogenes monoculture DSB were comparatively lower i.e., 5.7 ± 0.4 (0 h), 3.8 ± 0.1 (24 h), and 3.4 ± 0.6 (48 h), and 2.6 ± 0.3 (72 h). However, when co-cultured with P. aeruginosa, L. monocytogenes exhibited consistently higher cell densities 6.7 ± 0.4, 6.0 ± 0.9, 5.6 ± 0.04, and 4.9 ± 0.6, at 0, 24, 48, and 72 h, respectively. On average, P. aeruginosa consistently exceeded six log10 at each desiccation time point in co-culture. Confocal laser scanning microscopy (CLSM) images confirmed biofilm development and persistence over time in mono and mixed cultures. This work provides foundational evidence toward better understanding pathogen survival under dehydrated conditions, interactions between different pathogens within desiccated biofilms, and their respective survival rates. Additionally, these data provide quantitative assessment of bacterial load within DSB under high-risk scenarios for LMFs. These models provide opportunities to explore targeted mitigation strategies, including efficacy of dry sanitation practices, to prevent the formation or remove DSB in LMF processing environments.

Bacterial Contamination and Antimicrobial Resistance in Two-Spotted (Gryllus bimaculatus) and House (Acheta domesticus) Cricket Rearing and Harvesting Processes.

Food safety for cricket production is a crucial factor in producing edible crickets with safety for consumers and sustainability for two-spotted (Gryllus bimaculatus) as well as house (Acheta domesticus) cricket production. This study was conducted by simultaneously rearing two cricket species, comprising two-spotted crickets (G. bimaculatus) and house crickets (A. domesticus). A total of 16 rearing crates were used for the present study, which were allocated into 8 rearing crates for each studied cricket species, including paper egg cartons. Cricket eggs were incubated in the rearing crates. Once the crickets hatched, tap water and powdered feed were provided ad libitum throughout the experiment. At the end of this study (35 and 42 days for the two-spotted and house crickets, respectively), all crickets were harvested, rinsed in tap water, and boiled in water for 5 min. During the rearing and harvesting processes, samples were collected from various potential contamination points for bacteria, including E. coli and Salmonella spp. There were samples of the initial input (feed, drinking water, and staff hands), rearing environment (water pipe, crate wall, living cartons, frass, and cricket surface), and harvesting crickets (harvested, washed, and boiled crickets), with a 2-week sampling interval, except for the last round of sampling for the two-spotted crickets. Subsequently, all samples were submitted to isolate and identify contaminated bacteria. The samples from the last round of sampling for both kinds of crickets were submitted to quantify the level of contamination for E. coli and Salmonella spp., including antimicrobial resistance by the disk diffusion method for the positive isolate. The results showed that bacterial contamination was found in the rearing of both cricket species, primarily involving Klebsiella spp. and Enterobacter spp., mainly found in prepared drinking water and the water pipes of drinking water supply equipment, which are potential sources of contamination with cricket frass. E. coli was found in 4.8% and 4.3% of the two-spotted and house crickets, respectively, while no presence of Salmonella spp. was detected in any submitted samples. The quantification of E. coli and Salmonella spp. indicated E. coli contamination near the water pipe and the frass of two-spotted crickets, but Salmonella spp. was undetectable in both two-spotted and house crickets. The antimicrobial resistance of isolated E. coli mainly involved penicillin G, amoxicillin, ampicillin, erythromycin, lincomycin, and tiamulin. Thus, good farm management with proper sanitation practices (such as cleaning and keeping the environment dry), as well as boiling crickets during the harvesting process, may help ensure the safety of edible cricket production.

Effectiveness of Ultraviolet Radiation and Disinfectant Wipes in Reducing the Microbial Contamination of Mobile Phones in a Tertiary Care Hospital.

Background As mobile phones act as a potential source of microbial contamination, particularly in a hospital environment, the effectiveness of two most debated interventions namely ultraviolet radiation and disinfectant wipes in reducing the microbial contamination of mobile phones is compared. Objective To screen the mobile phones of healthcare personnel for the presence of microorganisms and to compare the effectiveness of ultraviolet radiation and disinfectant wipes in reducing microbial contamination. Methods and materials Pre-intervention and post-intervention swabs were collected before and after the use of each intervention respectively using 56 samples and cultured for growth in nutrient agar. Agar plates are subjected to quantitative analysis using bacterial colony count to reflect the efficacy of the specific intervention used. The data collected was entered in Microsoft Excel (Microsoft® Corp., Redmond, WA, USA) and analysis was done using standard statistical packages. Results While comparing the pre-intervention bacterial load with the post-intervention load, post-intervention bacterial contamination in terms of colony-forming units/CFU has drastically reduced after both interventions, which is validated by statistical significance. However, it was observed participants using disinfectant wipes as intervention had 2.07 times higher chance of having a low bacterial load which wasn't statistically significant. Conclusion Our study shows that with the use of any intervention from the above-mentioned interventions, bacterial loador bacterial contamination can be reduced significantly, thuspointing out that both ultraviolet radiation and disinfectant wipes are effective in reducing contamination of mobile phones. It was also found that male doctors have more bacterial load than females, which can be minimized by effectively changing behavioral habits.

Improve The Microbiological Quality of Groundwater Around Bonoloyo Cemetery by Boiling

Public cemeteries are considered to be a potential source of groundwater pathogen contamination. Many settlements in Indonesia are located near cemeteries and rely on groundwater for consumption. However, there is no information available on whether the simple method of boiling can improve the microbiological quality of groundwater around cemeteries. Therefore, this experimental study aimed to determine the effectiveness of boiling in improving the microbiological quality of groundwater around Bonoloyo Cemetery. The study had two treatments: groundwater without boiling (control) and groundwater that had been boiled. Samples were collected from two points (S1 and S2) inside the cemetery and three points (S3, S4, and S5) outside the cemetery. The microbiological quality of groundwater was analyzed using the MPN method for each treatment. Samples that produced gas in positive tubes were inoculated on eosin methylene blue (EMB) media. The results of the study showed that S1, S2, S3, and S5 had total coliform levels that exceeded the normal threshold for water. Fecal coliform was found in S3 and S5. However, after boiling, there was an average decrease in total coliforms in samples S1, S3, S4, and S5. There was also no growth of E. coli in samples S3 and S5. The decrease in MPN values ​​in the samples indicates that boiling can improve the microbiological quality of groundwater at cemetery Bonoloyo Surakarta.

Application and Experimental Substantiation of the Radioecological Model for Prediction in Behavior 90Sr in Cultivated Soil-Crop System: A Case Study of Two Experimental Agricultural Fields.

The radioactive fission product 90Sr has a sufficient half-life (28.8 years) to be detected long after its appearance in the environment. After its uptake into the soil-edible plant system, it enters the food chain and represents a potential source of contamination that threatens human health. Due to these facts, tracking the distribution of the artificial radionuclide 90Sr in the soil-edible plant system is a subject of intense research. The tracking of the 90Sr radionuclide distribution in the soil profile, as well as in the crops on the long-term experimental fields was carried out using beta radiation spectrometry. The radiochemical analytical method was used to analyze the 90Sr content in cultivated soil and crops. The conducted study focused on the experimental substantiation of the developed model for predicting the behavior of 90Sr in the cultivated soil-crop system. The results of using the applied radioecological model for the transfer of 90Sr from the soil to the above-ground part of crops showed a relatively good agreement with the experimentally determined values of the soil-crop transfer factor, which indicates that the used model can be successfully applied for the prediction of the behavior of 90Sr in the soil-soil solution-crop system.

A metagenomic assessment of bacterial community in spices sold open-air markets in Saint-Louis, Senegal

Natural spices play an essential role in human nutrition and well-being. However, their processing on different scales can expose them to potential sources of contamination. This study aimed to describe the bacterial community genomic footprint in spices sold in Senegal. Spice samples were collected in August 2022 in Saint-Louis, Senegal. The genomic region coding bacterial 16S rRNA was then amplified and sequenced using Oxford Nanopore Technology (ONT). Sequencing was carried out on two batches of samples, one containing part of the “Local Spices or Herbs” (n = 10), and the other, a mixture of 7 spices, Curcuma, Thyme and the other part of the “Local Spices or Herbs” (n = 39). Results showed high bacterial diversity and the predominance of Escherichia coli and Salmonella enterica in samples, with total reads of 65,744 and 165,325 for the two batches, respectively. The sample category “Homemade mixture of food condiments “, which includes all “Local Spices or Herbs” samples, showed remarkable bacterial diversity. These were followed by Curcuma, a blend of 7 spices and thyme. Also, the different categories of spices studied show similarities in their bacterial composition. These results highlight the microbial community’s highly diverse genomic profile, including pathogenic bacteria, in spice samples.

Sezonowa i przestrzenna zmienność jakości wody w systemie jezior Lumina-Rosu w delcie Dunaju w Rumunii

The main aim of the present scientific paper is to assess water quality of the surface water of various lakes located in the Lumina-Rosu interdistributary depression, Danube Delta, Romania. As specific objectives, the paper considered to spot the main potential sources of contamination and their environmental impacts on aquatic ecosystems. Equally, the purpose of the article is to emphasize the importance of monitoring the water quality of the Danube Delta, for preserving these unique natural water resources and their ecosystem services (fresh water, biodiversity, flood control, recreation, nutrient cycling, fishing and other traditional activities, ecotourism). Surface water samples collected from several control sections situated on the main tributaries and canals, as well as from lakes were investigated physically (To - C, EC - μS/cm, TDS - mg/L, turbidity - NTU units, TSS - mg/L) and chemically (pH - units, DO - mg/L, N-NO2- - mg/L, N-NO3- - mg/L, P-PO43-- mg/L, Chla - mg/L, SiO2 - mg/L, TOC - mg/L, SO42- - mg/L, S2- - mg/L, H2S - mg/L and synthetic detergents - mg/L). Generally, the hydro-physical-chemical characteristics and water quality assessment of the surface waters of the lakes manifest the combined effect of both processes occurred in the catchment (weathering, sediment supply and transport), as well as the in situ lake processes (photosynthesis, sediment mixing, biogeochemical cycling, evaporation, eutrophication, productivity changes). Overall, the physical and chemical characteristics of the sampling sites investigated at high waters of the Danube are quite similar to those measured at low waters. The differences that mainly occurred within the lakes are more related to the limnological variables and the local environmental conditions. Anyway, a significant seasonal variation was noticed in the lakes, during the dry period, when different physical and chemical characteristics appeared to be influenced by high air temperature, lack of precipitation, low water level regime, low dissolved oxygen level regime, all related to climate change effects etc. Moreover, the anthropogenic factor that left its mark on some physical-chemical characteristics of water should not be omitted either. However, the results obtained within this study did not show such alarming values as might have dangerous effects on the investigated aquatic environments. The water quality information within this case study may be used for improving the understanding of the water quality issues and to better coordinate and plan for future monitoring activities in and around the Danube Delta environment. The results will contribute to updating the existing database with relevant information for a sustainable future of the Danube Delta and in similar areas that are subjected to such environmental challenges.

Non-gaussian hydraulic conductivity and potential contaminant source identification: A comparison of two advanced DLPM-based inversion framework

Accurate identification of hydraulic conductivity fields (K) and contaminant source parameters is imperative for the enhanced assessment and effective remediation of polluted aquifers. Given the challenges posed by non-Gaussian distributions, high dimensionality, and ill-posed nature of groundwater inversion problems, reducing unknowns is a common strategy. Unlike conventional parameterization methods constrained by prior assumptions, this research introduces an innovative deep learning-based parameterization method (DLPM), AEdiffusion. AEdiffusion combines a Diffusion Denoising Probabilistic Model (DDPM) with a Variational Autoencoder (VAE) through a generator-refiner strategy, enabling the generation of high-dimensional K fields from low-dimensional latent representations. Additionally, this study examines the application of Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN-GP), another advanced DLPM, in groundwater inversion. Through comparative analysis within a Data Assimilation (DA) framework, focusing on non-Gaussian K fields and three potential contaminant sources under varied data availability scenarios, this study reveals that both DLPM-based inversion frameworks are capable of identifying K fields and the true contaminant sources. Notably, the AEdiffusion-based framework excels in extracting critical information from sparse observations, delivering more stable performance, but at the cost of increased time consumption compared to WGAN-GP-based framework.

Heavy metal and metalloid concentrations in red deer (Cervus elaphus) and their human health implications from One Health perspective

The red deer is an ungulate and large game species. The contamination of the ecosystems by metal(loid)s may lead to the exposure of animals (as well as humans) through water and food resources. The direct contact of hunters and wild animal meat consumers with deer carcasses may be a potential contaminant source. This study aimed to determine the metal(loid)s’ concentrations in the liver and kidney of red deer from two regions of Portugal (Idanha-a-Nova and Lousã), and to relate these with histopathologic lesions. Thirteen young male deer were submitted to metal(loid) determination (As, Cd, Co, Cr, Cu, Pb, and Zn) by inductively coupled plasma mass spectrophotometry (ICP-MS) and histopathology examination. Renal Cd (8.072 ± 5.766 mg/kg dw) and hepatic Pb (3.824 ± 6.098 mg/kg dw) mean values were high, considering the maximum values for consumption established by the European Commission. The hepatic mean value of Cu was significantly higher in Idanha-a-Nova (150.059 ± 33.321 mg/kg dw), and it is at the Cu toxicity limit considered for ruminants (150 mg/kg). The pollution induced by Panasqueira mines (Castelo Branco) may be a possible explanation for some of the findings, especially the higher values of hepatic Cu and Pb found in Idanha-a-Nova deer. These results have high importance under a One Health perspective, since they have implications in public health, and pose at risk the imbalance of animal populations and ecosystems.

Use of plasma process diagnostic sensors for the monitoring of in situ dry cleaning of plasma enhanced chemical vapor deposition chamber

A potential source of particle contamination due to poorly maintained PECVD chamber condition forces to perform in situ dry cleaning also actively employed before the wet-cleaning chamber maintenance period. In this paper, we demonstrate the use of plasma process diagnostic sensors, optical emission spectroscope, and quadrupole mass spectrometer for in situ plasma monitoring of the dry-cleaning step. It is worthwhile to know the thin film residue on the chamber’s inner wall, but it is difficult to collect the deposited thin film sample from the wall since the preparation of the sample from the equipment is impossible. To alleviate the concern, we prepared silicon wafer samples mounted on the chamber sidewall over the prolonged exposure of the SiO2 deposition process, and the collected sensory data were investigated under the dry-cleaning condition. The residue film obtained through the experiment was characterized by Fourier transform infrared, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. We found a useful insight into the chamber dry-cleaning end point detection application through residual gas analysis, and the results contribute to process engineers setting up the in situ dry-cleaning recipe to make sure that subsequent deposition can be consistently maintained.

Sources of propionic acid bacteria contamination in the milking parlor environment on Alpine Dairy Farms

High quality raw milk is an important prerequisite for the production of long ripened raw milk cheeses. This implies not only the absence of pathogenic microorganisms in raw milk, but also low levels of spoilage bacteria, including dairy propionic acid bacteria (dPAB), that can cause blowing and sensory defects in cheese, resulting in severe economic losses for producers. Raw milk contamination with dPAB has been primarily associated with improperly cleaned milking systems, but they have been detected in feed, soil, feces and on the teat skin. The objective of this study was to identify potential sources of raw milk contamination with dPAB in the barn and milking parlor environments. We also wanted to know more about the prevalence of the dPAB species in these environments and the levels of contamination. For this purpose, 16 small scale Alpine dairy farms were visited in August 2022: samples were taken from the barn environment (e.g., swab samples, air, feed, bedding), the milking system (swab samples, residual cleaning water, cleaning sponges, milk filters) and milk samples were collected at various sampling points along the milking system. Samples were analyzed for dPAB contamination, and results showed contamination at multiple sampling locations. We observed potential adverse effects of improperly set cleaning parameters of the milking system, as well as of farm specific practices. In addition, we identified cleaning water residues as an important source of contamination. Based on these findings, we propose potential mitigation strategies to reduce the risk of raw milk contamination with cheese spoilage bacteria, thereby contributing to a more sustainable food production.

Atmospheric concentrations and potential sources of dioxin-like contaminants to Acadia National Park

Acadia National Park (ANP) is located on Mt. Desert Island, ME on the U.S. Atlantic coast. ANP is routinely a top-ten most popular National Park with over four million visits in 2022. The overall contribution and negative effects of long-range atmospheric transport and local sources of dioxin-like contaminants endangering natural and wildlife resources is unknown. Dioxin-like (DL) contaminants polychlorinated dibenzo-p-dioxins (∑PCDD) and polychlorinated dibenzofurans (∑PCDF), non-ortho coplanar PCBs (∑CP4), and polychlorinated naphthalenes (∑PCNs) were measured at the McFarland Hill air monitoring station (44.37⁰N, 68.26⁰W). On a mass/volume basis, total PCNs averaged 90.9 % (788 fg/m3) of DL contaminants measured annually, with 92.9 % of the collected total in the vapor-phase. Alternatively, total dioxin/furans (∑PCDD/Fs) represented 71.6 % of the total toxic equivalence (∑TEQ) (1.018 fg-TEQ/m3), with 69.7 % in the particulate-phase. Maximum concentrations measured for individual sampling events for ∑PCDD/F, ∑CP4, and ∑PCN were 159 (winter), 139 (summer), and 2100 (autumn), fg/m3 respectively. Whereas the maximum ∑TEQ concentrations for individual sampling events for ∑PCDD/F, ∑CP4, and ∑PCN were 2.8 (autumn), 0.38 (summer), and 0.71 (autumn), fg-TEQ/m3 respectively. Pearson correlations were calculated for ∑PCDD/Fs and ∑PCN particulate/vapor-phase air concentrations and PM2.5 wood smoke “indicator” species. The most significant correlations were observed in autumn for particulate-phase ∑PCDD/Fs suggesting a relationship between visitation-generated combustion sources (campfires and/or waste burning) or climate-change mediated forest fires. Significant Clausius-Clapeyron (C–C) correlations observed for particulate-phase ∑PCDDs (r2 = 0.567) as ambient temperatures decreased suggests a connection between localized domestic heating sources or visitor-based burning of wood/trash resources. Alternatively, highly significant C–C vapor-phase ∑CP4-PCBs correlations (r2 = 0.815) implies that the majority of ∑CP4-PCB loading to ANP is from long-range atmospheric transport processes. Based on these findings, Acadia National Park should be classified as a remote site with minor depositional impacts from ∑PCDD/Fs, ∑CP4-PCBs, and ∑PCN atmospheric transport or local diffuse sources.

The impact of kit, environment, and sampling contamination on the observed microbiome of bovine milk.

In low-microbial biomass samples such as bovine milk, contaminants can outnumber endogenous bacteria. Because of this, milk microbiome research suffers from a critical knowledge gap, namely, does non-mastitis bovine milk contain a native microbiome? In this study, we sampled external and internal mammary epithelia and stripped and cisternal milk and used numerous negative controls, including air and sampling controls and extraction and library preparation blanks, to identify the potential sources of contamination. Two algorithms were used to mathematically remove contaminants and track the potential movement of microbes among samples. Results suggest that the majority (i.e., >75%) of sequence data generated from bovine milk and mammary epithelium samples represents contaminating DNA. Contaminants in milk samples were primarily sourced from DNA extraction kits and the internal and external skin of the teat, while teat canal and apex samples were mainly contaminated during the sampling process. After decontamination, the milk microbiome displayed a more dispersed, less diverse, and compositionally distinct bacterial profile compared with epithelial samples. Similar microbial compositions were observed between cisternal and stripped milk samples, as well as between teat apex and canal samples. Staphylococcus and Acinetobacter were the predominant genera detected in milk sample sequences, and bacterial culture showed growth of Staphylococcus and Corynebacterium spp. in 50% (7/14) of stripped milk samples and growth of Staphylococcus spp. in 7% (1/14) of cisternal milk samples. Our study suggests that microbiome data generated from milk samples obtained from clinically healthy bovine udders may be heavily biased by contaminants that enter the sample during sample collection and processing workflows.IMPORTANCEObtaining a non-contaminated sample of bovine milk is challenging due to the nature of the sampling environment and the route by which milk is typically extracted from the mammary gland. Furthermore, the very low bacterial biomass of bovine milk exacerbates the impacts of contaminant sequences in downstream analyses, which can lead to severe biases. Our finding showed that bovine milk contains very low bacterial biomass and each contamination event (including sampling procedure and DNA extraction process) introduces bacteria and/or DNA fragments that easily outnumber the native bacterial cells. This finding has important implications for our ability to draw robust conclusions from milk microbiome data, especially if the data have not been subjected to rigorous decontamination procedures. Based on these findings, we strongly urge researchers to include numerous negative controls into their sampling and sample processing workflows and to utilize several complementary methods for identifying potential contaminants within the resulting sequence data. These measures will improve the accuracy, reliability, reproducibility, and interpretability of milk microbiome data and research.

Urban stormwater green infrastructure: Evaluating the public health service role of bioretention using microbial source tracking and bacterial community analyses

Bioretention cells (BRCs) control stormwater flow on-site during precipitation, reducing runoff and improving water quality through chemical, physical, and biological processes. While BRCs are effective in these aspects, they provide habitats for wildlife and may face microbial hazards from fecal shedding, posing a potential threat to human health and the nearby environment. However, limited knowledge exists regarding the ability to control microbial hazards (e.g., beyond using typical indicator bacteria) through stormwater biofiltration. Therefore, the purpose of this study is to characterize changes in the bacterial community of urban stormwater undergoing bioretention treatment, with the goal of assessing the public health implications of these green infrastructure solutions. Samples from BRC inflow and outflow in Columbus, Ohio, were collected post-heavy storms from October 2021 to March 2022. Conventional culture-based E. coli monitoring and microbial source tracking (MST) were conducted to identify major fecal contamination extent and its sources (i.e., human, canine, avian, and ruminant). Droplet digital polymerase chain reaction (ddPCR) was utilized to quantify the level of host-associated fecal contamination in addition to three antibiotic resistant genes (ARGs): tetracycline resistance gene (tetQ), sulfonamide resistance gene (sul1), and Klebsiella pneumoniae carbapenemase resistance gene (blaKPC). Subsequently, 16S rRNA gene sequencing was conducted to characterize bacterial community differences between stormwater BRC inflow and outflow. Untreated urban stormwater reflects anthropogenic contamination, suggesting it as a potential source of contamination to waterbodies and urban environments. When comparing inlet and outlet BRC samples, urban stormwater treated via biofiltration did not increase microbial hazards, and changes in bacterial taxa and alpha diversity were negligible. Beta diversity results reveal a significant shift in bacterial community structure, while simultaneously enhancing the water quality (i.e., reduction of metals, total suspended solids, total nitrogen) of urban stormwater. Significant correlations were found between the bacterial community diversity of urban stormwater with fecal contamination (e.g. dog) and ARG (sul1), rainfall intensity, and water quality (hardness, total phosphorous). The study concludes that bioretention technology can sustainably maintain urban microbial water quality without posing additional public health risks, making it a viable green infrastructure solution for heavy rainfall events exacerbated by climate change.

Prevention is the Only Cure: Health Effects of the Uranium Cycle on Women, Fetuses and Children

There are many sources of potential contamination throughout the uranium cycle, which can affect the health of families for generations to come. Children and fetuses are especially vulnerable due to rapid cell division during physical growth. This is documented internationally through outcomes such as increased incidence in spontaneousabortions,childhoodleukemiaandotherchildhoodcancers. Researchonthistopicaroseoutofa local concern in eastern Ontario due to proposed uranium mines at the watershed of major rivers, which may pose arisktomidwiferyclients wholiveneartailingponds,incommunitieswhorelyontheriversfortheirsourceof water, or who work in reprocessing and nuclear power plants. As Canada is the world's largest producer and exporter of uranium, the health impacts extend to the most recent use of depleted uranium in weapons abroad. As primary health practitioners, midwives can play a role in promoting public health through becoming better informed, and supporting local and international initiatives which address the threat posed to human and environmental health by the uranium cycle.

Evaluation of Hydrogeochemical Processes for Irrigation Use and Potential Nitrate Contamination Sources in Groundwater Using Nitrogen Stable Isotopes in Southwest, India: A Case Study

Evaluation of Hydrogeochemical Processes for Irrigation Use and Potential Nitrate Contamination Sources in Groundwater Using Nitrogen Stable Isotopes in Southwest, India: A Case Study

PFAS-Contaminated Pesticides Applied near Public Supply Wells Disproportionately Impact Communities of Color in California.

Contaminated drinking water from widespread environmental pollutants such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) poses a rising threat to public health. PFAS monitoring in groundwater is limited and fails to consider pesticides found to contain PFAS as a potential contamination source. Given previous findings on the disproportionate exposure of communities of Color to both pesticides and PFAS, we investigated disparities in PFAS-contaminated pesticide applications in California based on community-level sociodemographic characteristics. We utilized statewide pesticide application data from the California Department of Pesticide Regulation and recently reported concentrations of PFAS chemicals detected in eight pesticide products to calculate the areal density of PFAS applied within 1 km of individual community water systems' (CWSs) supply wells. Spatial regression analyses suggest that statewide, CWSs that serve a greater proportion of Latinx and non-Latinx People of Color residents experience a greater areal density of PFAS applied and greater likelihood of PFAS application near their public supply wells. These results highlight agroecosystems as potentially important sources of PFAS in drinking water and identify areas that may be at risk of PFAS contamination and warrant additional PFAS monitoring and remediation.

Shiga Toxin-Producing Escherichia coli O157:H7 Illness Outbreak Associated with Untreated, Pressurized, Municipal Irrigation Water - Utah, 2023.

During July-September 2023, an outbreak of Shiga toxin-producing Escherichia coli O157:H7 illness among children in city A, Utah, caused 13 confirmed illnesses; seven patients were hospitalized, including two with hemolytic uremic syndrome. Local, state, and federal public health partners investigating the outbreak linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW) exposure in city A; 12 of 13 ill children reported playing in or drinking UPMIW. Clinical isolates were genetically highly related to one another and to environmental isolates from multiple locations within city A's UPMIW system. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of UPMIW. Public health and city A officials issued multiple press releases regarding the outbreak reminding residents that UPMIW is not intended for drinking or recreation. Public education and UPMIW management and operations interventions, including assessing and mitigating potential contamination sources, covering UPMIW sources and reservoirs, indicating UPMIW lines and spigots with a designated color, and providing conspicuous signage to communicate risk and intended use might help prevent future UPMIW-associated illnesses.