From a health prospective, it is critical to provide a comprehensive model which integrates all the parameters involved in virus transmission and its consequences on human body. In order to estimate the health risks, for workers and residents, associated with an exposure airborne viruses emitted from a wastewater treatment (WWTP), the concentration levels of viruses in emitted bioaerosols over a twelve-month period were measured by real-time polymerase chain reaction (RT-PCR). A combined Gaussian plum dispersion model and quantitative microbial risk assessment (QMRA) with Monte-Carlo simulation served as suitable explanatory tools to estimate the risk of acquiring gastrointestinal illness (GI) due to exposure to air containing Rotavirus (RoV) and Norovirus (NoV) bioaerosols. Additionally, DALY metric was applied to quantify the disability and mortality for workers and residents. RoV and NoV were detected above aeration tank with annual mean concentration 27 and 3099 (Viruses/m³.h), respectively. The medium calculated DALY indicator based on viral loads in contaminant source (RoV:5.76 × 10⁻² and NoV:1.23 × 10⁻¹) and estimated in different distances away (300–1000 m) (RoV:2.87 × 10⁻²- 2.75 × 10⁻² and NoV:1.14 × 10⁻¹-1.13 × 10⁻¹) were markedly higher than the threshold values recommended by US EPA (10⁻⁴ DALY pppy) and WHO (10⁻⁶ DALY pppy). The sensitivity analysis highlighted dose exposure and disease burden per case (DBPC) as two most influential factors for both workers and residents following exposure to two pathogens of concern. Due to high resistance and high concentration in the environment, the presence of RoV and NoV can intensify the consequences of diarrhea especially for children under five years of age; A comprehensible and transparent presentation of DALYs and QMRA can help decision makers and responsibilities to justify the priorities of exposure to wastewater in comparison with other risks of daily life.

Hexafluoropropylene oxide dimer acid (HFPO-DA) is the substitute for perfluoro octanoic acid (PFOA), and recently it has been detected in environmental water samples worldwide and has multiple toxicities. However, whether it will affect the intestines and gut microbiota remains unclear. In this study, in order to evaluate the gut toxicity of HFPO-DA in mammals, male mice were orally exposed to 0, 2, 20, 200 μg/L HFPO-DA, respectively, for 6 weeks. Our results showed that HFPO-DA exposure caused colonic inflammation which was coupled with increased TNF-α levels in serum and increased mRNA expression levels of TNF-α, p65, TLR4, MCP-1 of the colon in mice after exposure to 200 μg/L HFPO-DA. We also found that HFPO-DA exposure induced the decreased mRNA expression levels and protein levels of MUC2 and ZO-1, which means the dysfunction of gut barrier in the colon. In the ileum, we found that HFPO-DA exposure induced the increased mRNA expression levels of various inflammatory factors, but no obvious changes was found to barrier function. Additionally, HFPO-DA exposure caused the imbalance of cecal gut microbiota and changes of cecal microbiota diversity. Taken together, all these results indicate the potential gut toxicity of HFPO-DA and is perceived as a major problem of health risk that affects the inflammation, gut barrier dysfunction, and gut microbiota disturbance in mammals.

F-53B (6:2 chlorinated polyfluorinated ether sulfonate) is currently recognized as a safe alternative to long-chain PFASs in China. However, an increasing number of studies have recently authenticated its biotoxicological effects. In this study, for evaluating the gut toxicity of F-53B in mammals, both female and male mice were orally exposed to 0, 1, 3, or 10 μg/L F-53B for 10 weeks. Our results showed that F-53B significantly accumulated in the colon, ileum and serum when exposed to 10 μg/L F-53B for 10 weeks. F-53B exposure not only increased the transcriptional levels of ion transport-related genes but could also interact with the CFTR protein directly. Interestingly, subchronic F-53B exposure also increased the transcription of mucus secretion-related genes, but the protein level of Muc2 decreased after F-53B exposure, indicating that there was a compensatory phenomenon after mucus barrier injury. Furthermore, F-53B exposure also induced colonic inflammation associated with gut microbiota dysbiosis in the colon. Taken together, our results indicated that the potential gut toxicity of F-53B and almost all of the changed parameters were significantly affected in both female and male mice, suggesting that F-53B could disturb the gut barrier without sex dependence in mice.

Occupational and experimental studies have revealed the organs most affected by dimethylformamide (DMF) are liver and gastrointestinal tract. However, few studies have focused on the potential effect of outdoor pollution of DMF. This study examined the health risk of hospitalization due to digestive system disease by time series studies in a case city Longwan, China. The urine metabolite of DMF was correlated well with DMF exposure concentration (EC). A 101.0-μg/m3 (interquartile range) increase in the two-day moving average of DMF EC was associated with a 1.10 (1.01 ˜ 1.20), 1.22 (1.10 ˜ 1.35), and 1.05 (0.90 ˜ 1.22) increase in hospitalization for total digestive system diseases, liver disease, and gastrointestinal tract disease, respectively. The exposure-dose response between DMF and the relative risk of liver disease was linear only below 350 μg/m3. These findings highlight a previously unrecognized health problem related to VOCs released into the outdoor environment.

This paper examined the gut digestive enzymes, trypsin and leucine aminopeptidase (LAP), in gypsy moth (Lymantria dispar, L.) larvae exposed to cadmium. We analyzed the 3-day acute effect, chronic effects from hatching until sacrifice, and recovery from long-term dietary treatment with cadmium concentrations of 10 and 30 μg Cd/g dry food. The activities of both examined enzymes declined at the higher level of cadmium after both acute and chronic treatments and did not recover within 3 days of feeding a diet with no added cadmium. Leucine aminopeptidase was more sensitive because its activity was inhibited after both short-term treatments. Three trypsin and one leucine aminopeptidase isoform were detected by electrophoresis. Egg hatches (full-sib families) differed in enzyme activities, index of phenotypic plasticity, and isozyme expression after different treatments. Statistically significant positive correlations between these enzymes pointed to common genetic regulation. Moreover, variances were higher for the control group than for cadmium treatment groups implying that these proteolytic enzymes did not participate directly in detoxification. These results suggest that, with additional research to discover the mechanisms of enzyme inhibition, trypsin and leucine aminopeptidase might be used as biomarkers to indicate the severity of gastrointestinal disease due to cadmium intake.

One of the highest self-reported incidence rates of acute gastrointestinal illness (AGI) in the global peer-reviewed literature occurs in Inuit communities in the Canadian Arctic. This high incidence of illness could be due, in part, to the consumption of contaminated water, as many northern communities face challenges related to the quality of municipal drinking water. Furthermore, many Inuit store drinking water in containers in the home, which could increase the risk of contamination between source and point-of-use (i.e., water recontamination during storage). To examine this risk, this research characterized drinking water collection and storage practices, identified potential risk factors for water contamination between source and point-of-use, and examined possible associations between drinking water contamination and self-reported AGI in the Inuit community of Rigolet, Canada. The study included a cross-sectional census survey that captured data on types of drinking water used, household practices related to drinking water (e.g., how it was collected and stored), physical characteristics of water storage containers, and self-reported AGI. Additionally, water samples were collected from all identified drinking water containers in homes and analyzed for presence of Escherichia coli and total coliforms. Despite municipally treated tap water being available in all homes, 77.6% of households had alternative sources of drinking water stored in containers, and of these containers, 25.2% tested positive for total coliforms. The use of transfer devices and water dippers (i.e., smaller bowls or measuring cups) for the collection and retrieval of water from containers were both significantly associated with increased odds of total coliform presence in stored water (ORₜᵣₐₙₛfₑᵣ dₑᵥᵢcₑ = 3.4, 95% CI 1.2–11.7; ORdᵢₚₚₑᵣ = 13.4, 95% CI 3.8–47.1). Twenty-eight-day period prevalence of self-reported AGI during the month before the survey was 17.2% (95% CI 13.0–22.5), which yielded an annual incidence rate of 2.4 cases per person per year (95% CI 1.8–3.1); no water-related risk factors were significantly associated with AGI. Considering the high prevalence of, and risk factors associated with, indicator bacteria in drinking water stored in containers, potential exposure to waterborne pathogens may be minimized through interventions at the household level.

Wastewater management in Canadian Arctic communities is influenced by several geographical factors including climate, remoteness, population size, and local food-harvesting practices. Most communities use trucked collection services and basic treatment systems, which are capable of only low-level pathogen removal. These systems are typically reliant solely on natural environmental processes for treatment and make use of existing lagoons, wetlands, and bays. They are operated in a manner such that partially treated wastewater still containing potentially hazardous microorganisms is released into the terrestrial and aquatic environment at random times. Northern communities rely heavily on their local surroundings as a source of food, drinking water, and recreation, thus creating the possibility of human exposure to wastewater effluent. Human exposure to microbial hazards present in municipal wastewater can lead to acute gastrointestinal illness or more severe disease. Although estimating the actual disease burdens associated with wastewater exposures in Arctic communities is challenging, waterborne- and sanitation-related illness is believed to be comparatively higher than in other parts of Canada. This review offers a conceptual framework and evaluation of current knowledge to enable the first microbial risk assessment of exposure scenarios associated with food-harvesting and recreational activities in Arctic communities, where simplified wastewater systems are being operated.