Sewage Contamination Research Articles

IJCM_300A: Clinical medicine and Public health: Is the dichotomy justified? Epidemiological investigation of a Hepatitis A case admitted at a tertiary care hospital

Background: Outbreaks of Hepatitis A Virus (HAV) infection have been associated with poor sanitation, inadequate sewage disposal and contamination of food and water. Objective: To identify the epidemiological factors associated with a patient who presented with fever and vomiting and diagnosed with Hepatitis A. Methodology: 23-year-old, female patient was admitted in the general medicine department of a tertiary care hospital with complaints of fever and vomiting. IgM ELISA tests for Hepatitis A and Hepatitis E were positive. The patient’s mother had similar symptoms. Community Medicine department was informed about the patient. A team comprising of postgraduate students, MSW, ASHA worker and Anganwadi worker visited the patient’s house. Information including clinical history, source of drinking water, history of food and water intake from outside, sanitation and waste disposal methods of the house hold were collected. Stakeholders including the counsellor and members of the self-help group of the area were informed. House to house visit of all houses in 200 meters radius from patients’ house was done to look for more cases and to assess the environment sanitation. Results: The team identified that the source of drinking water of the patient’s family was a well which was not sanitary. A nearby house was identified with an open well with open sullage less than one meter away. Seven children of that household had fever and jaundice and were treated from a local hospital, one week prior. Stakeholders were also informed and both the wells were chlorinated and the families were educated about the importance of boiling water before consumption, proper disposal of sullage and waste disposal. Conclusion: Interdepartmental communication between clinical medicine and public health played an important role in identifying and eliminating the source of infection even when one patient was diagnosed and helped to prevent HAV outbreak.

Biochemical responses in Pacific oysters Magallana gigas (Thunberg, 1793): Tools to evaluate the environmental quality of aquaculture areas

The discharge of sanitary sewage into the bays of the Florianópolis Metropolitan Area (Southern Brazil), has led to the contamination of oyster farms. Consequently, linear alkylbenzenes (LABs) were quantified in the sediment, and the biochemical responses in gills and digestive gland of oysters from six farms were assessed. Our findings revealed elevated levels of LABs in the sediment of the Imaruim and Serraria farms. Additionally, alterations were observed in the antioxidant enzymes: catalase, glutathione peroxidase and superoxide dismutase in both oyster tissue from the Serraria, Santo Antonio de Lisboa and Sambaqui farms. Furthermore, correlation analyses indicated strong and moderate associations between biochemical responses, organic contaminants, and certain physicochemical parameters. Consequently, our results demonstrated the activation of the antioxidant system in oysters, representing a protective response to the presence of sanitary sewage and other contaminants. Therefore, we propose the utilization of biochemical biomarkers for monitoring the environmental quality of farms.

History of anthropogenic faece and sewage contamination to Lake Erhai in southwestern China over the past ∼200 years

Over the past decades, faece and sewage pollution from agricultural and industrial activities has induced severe eutrophication and ecosystem deterioration of Lake Erhai in southwestern China. Investigations on the anthropogenic faece and sewage input from both spatial and historical viewpoints are of great values for recovery strategies. In this study, we investigated fecal steroids in surface sediments from Lake Erhai collected in 2018, and found that the faece and sewage contamination is mainly from the southern region due to urban development, while the raw sewage contributes more in the northern region due to agriculture activities. We further applied fecal steroids to reconstruction of faece and sewage contamination to Lake Erhai over the past ∼200 years. The concentrations in fecal steroids remained low during ∼1820–1970, started to increase since the 1970s, and further increased after the 1990s, indicating a cumulative effect of contamination on the lake ecosystem by agricultural activities and urbanization practices. Diagnostic ratios of faece and sewage contamination over in-situ productivity remained stable or even decreased slightly during ∼1970–1980, and significantly increased during ∼1980–2008, suggesting that the contamination in Lake Erhai began at the 1980s. The fecal steroid records also demonstrated that even though anaerobic sewage treatment was in process, production of raw sewage still exceeded sewage treatment after the 1980s. Considerable faece and sewage contamination in the Lake Erhai catchment from anthropogenic industrialization and urbanization, which has also been observed from various environments throughout the world, asks for further efforts on regulations to protect water quality and human life. Fortunately, governmental regulations have significantly reduced the anthropogenic faece and sewage contamination to Lake Erhai over the past decades, highlighting a crucial role of sustainable management on lake ecosystem.

Removal of sulfamethoxazole and production of cyanobacterial lipid promoted by the construction of a consortium containing a non-toxic cyanobacterium and sewage bacteria

This study evaluated the possibility of constructing a consortium containing sewage bacteria and cyanobacterial cells immobilized by Ca-alginate for the advanced treatment of antibiotic-polluted sewage coupled to cyanobacterial lipid production. Two non-toxic cyanobacterial species (Synechococcus sp. and Chroococcus sp.) were exposed to 0.5–20.0 μg/L of sulfamethoxazole (SMZ) for 4 days. Comparison between suspended and immobilized conditions indicated that immobilization increased (p < 0.05) SMZ removal percentage without reducing cyanobacterial growth performance (indicated by OD680), chlorophyll-a content, dry cell weight, lipid content and lipid weight/productivity of each cyanobacterium. Chroococcus sp. presented better antibiotic removal and lipid production ability than Synechococcus sp. After the addition of immobilized Chroococcus sp. into sewage, sewage bacteria attached to the surface and filled the pores of cyanobacterial beads. Immobilized Chroococcus sp. promoted the succession of sewage microbial community towards the dominance of Cellvibrio, Flavobacterium, Formivibrio and Pseudomonas, which participated in denitrification, phosphate accumulation and antibiotic removal. In the sewage microbial community, various functional genes upregulated by immobilized Chroococcus sp. directly showed negative correlation (p < 0.05) with sewage contaminants, including gltB, glnA and napA responsible for nitrogen removal; pstS responsible for phosphorus removal; nqrF, cbhA, glgC, malZ, pulA, uxaA and maeA responsible for COD removal; frmA, katG, maeA, uxaA, carB and cbhA responsible for SMZ removal. Coexisting sewage bacteria elevated (p < 0.05) lipid productivity of immobilized Chroococcus sp. to 29.13–36.52 mg/L/day through the upregulation of various genes related to metabolite exchange and signal transduction. Cyanobacterial cells degraded SMZ in collaboration with sewage bacteria, through deamination, nitration, bond cleavage, hydroxylation, desulfonation and nitrosation. The cyanobacteria-bacteria consortium presented 4-day removal percentages of 54.58–68.39%, 66.14–68.69%, 95.77–96.31% and 81.09–82.35% for SMZ, TN, TP and COD, respectively. In general, the cyanobacteria-bacteria consortium achieved a good combination of cyanobacterial lipid productivity and sewage treatment efficiency.

Immediate versus early soft tissue coverage for severe open grade III B tibia fractures: a comparative clinical study

Controversy remains regarding timing in the management of grade III-B open tibia fractures. Many authors recommend an immediate definitive soft tissue coverage within a critical period of 12 hours, yet in many patients, this may be impossible due to concomitant injuries or delayed referral. The present case series aims to compare the role of immediate versus early soft tissue coverage for severe open grade III-B tibial fractures. 20 cases of tibial fractures of were divided into two groups; 10 cases each. Immediate group (within 12 hours) and early group (3-7 days), according to the soft tissue coverage time. Strict criteria for inclusion in the first group included debridement within 12 hours of injury, no sewage or organic contamination, the presence of bleeding skin margins, and the absence of systemic illness. All 20 cases had been treated by a debridement and soft-tissue cover with a muscle pedicle or fasio-cutanous flap. Functional outcome measures included deep infection rate, stable soft tissue coverage, number of inpatient’s stays, number of surgical procedures, and union time. The mean follow-up period was 24 months. Mean inpatient time was 30 and 41 days respectively. Mean surgical procedures were 2.2 and 3.4 respectively and union time was 26 versus 34 weeks. Mean inpatient time, mean surgical procedures per time and union time were pointedly less in the immediate flap coverage group which significantly improves results concerning early union, healing time, and cost of hospitalization and rehabilitation.

Detection and quantification of adenovirus, polyomavirus, and papillomavirus in urban sewage.

The objective of this study was to assess the occurrence and seasonal frequency of human adenovirus (HAdV), human polyomavirus (HPyV), and human papillomavirus (HPV) in urban sewage. The detection of these viruses was carried out by polymerase chain reaction (PCR), and then the viral concentrations in the positive samples were quantified by quantitative PCR (qPCR). Additionally, HAdV and HPyV genotyping was also performed by PCR. A total of 38/60 (63.3%) positive samples were found. HAdV was the most prevalent virus (26/60; 43.3%), followed by HPyV (21/60; 35%) and HPV (21/60; 35%). The viral concentrations ranged from 3.56 × 102 to 7.55 × 107 genome copies/L. The most common dual viral agents was found between HAdV and HPyV, in eight samples (8/38, 21%). HAdV types 40 and 41 as well as HPyV types JC and BK were identified, with HAdV-40 and HPyV JC being the most prevalent types. Furthermore, the detection rates of HAdV, HPyV, and HPV were higher during the winter season than the other seasons. The high prevalence of HAdV and HPyV supports their suitability as viral indicators of sewage contamination. Furthermore, this study demonstrates the advantages of environmental surveillance as a tool to elucidate the community-circulating viruses.

A Multi-Geochemical Characterization to Evaluate Anthropogenic Contamination in Marine Sediments from Port of Suape, Northeast of Brazil

To investigate the anthropogenic contamination of the Port of Suape, five surface sediments were collected and subjected to a geochemical characterization based on the determination of environmental biomarkers such as sterols, aliphatic and polycyclic aromatic hydrocarbons, and also metals and arsenic. Sterol analyses point to a moderate level of sewage contamination, while n-alkanes analyses indicated contamination by petroleum in an early stage of biodegradation. Polycyclic aromatic hydrocarbons analyses pointed to a mixture of contributions for the organic matter, which were predominantly found for petrogenic and pyrolytic sources. The quantification of trace metals indicated a low risk to the environment, except for As, which was identified as displaying moderate contamination. During the analysis of all biomarkers, the sediment collected near one of the shipyards was the most affected. These results enable comprehension of the level of contamination in an important Brazilian port and the need to develop remediation policies.

Availability of fresh water in cold climate regions

Challenges related to the availability of fresh water in cold climate regions are discussed with emphasis on possible degradation of the quality of drinking water. The permafrost in this region has been consistent in making sure there is little drainage in the ground. This is important, as fresh water is mainly supplied through melting water from snow and ice in the many winter months. Climate change and warmer weather plays a role in heating up the permafrost and increasing the rate of the melting snow. This has an impact on both the amount of water and potentially the drinking quality. In certain cold region areas, fresh water sources are located not far from the shore. With increased shorline erosion due to warming climate, the fresh water supply is in danger of being contaminated by salt water during large storm events. Furthermore, human activities such as road transport and sewage contamination do also have a significant impact on the water’s quality. A bowtie diagram will be used to illustrate the different risk factors and suggestions on how to maintain the quality of fresh water supplies in cold climate areas. The primary focus areas will be Isdammen, near Longyearbyen on Svalbard and Utqiagvik (formerly Barrow), Alaska.

Selective formation of high-valent iron in Fenton-like system for emerging contaminants degradation under near-neutral and high-salt conditions

In view of the near-neutral and high-salt conditions, the Fenton technology with hydroxyl radicals (HO•) as the main reactive species is difficult to satisfy the removal of trace emerging contaminants (ECs) in pharmaceutical sewage. Here, a layered double hydroxide FeZn-LDH was prepared, and the selective formation of ≡Fe(IV)=O in Fenton-like system was accomplished by the chemical environment regulation of the iron sites and the pH control of the microregion. The introduced zinc can increase the length of Fe-O bond in the FeZn-LDH shell layer by 0.22 Å compared to that in Fe2O3, which was conducive to the oxygen transfer process between ≡Fe(III) and H2O2, resulting in the ≡Fe(IV)=O formation. Besides, the amphoteric hydroxide Zn(OH)2 can regulate the pH of the FeZn-LDH surface microregion, maintaining reaction pH at around 6.5–7.5, which could avoid the quenching of ≡Fe(IV)=O by H+. On the other hand, owing to the anti-interference of ≡Fe(IV)=O and the near-zero Zeta potential on the FeZn-LDH surface, the trace ECs can also be effectively degraded under high-salt conditions. Consequently, the process of ≡Fe(IV)=O generation in FeZn-LDH system can satisfy the efficient removal of ECs under near-neutral and high-salt conditions.

Metagenomic analysis reveals diverse microbial community and potential functional roles in Baner rivulet, India

BackgroundThe health index of any population is directly correlated with the water quality, which in turn depends upon physicochemical characteristics and the microbiome of that aquatic source. For maintaining the water quality, knowledge of microbial diversity is a must. The present investigation attempts to evaluate the microflora of Baner. Metagenomics has been proven to be the technique for examining the genetic diversity of unculturable microbiota without using traditional culturing techniques. The microbial profile of Baner is analyzed using metagenomics for the first time to the best of our knowledge. ResultsTo explore the microbial diversity of Baner, metagenomics analysis from 3 different sites was done. Data analysis identified 29 phyla, 62 classes, 131 orders, 268 families, and 741 genera. Proteobacteria was found to be the most abundant phylum in all the sampling sites, with the highest abundance at S3 sampling site (94%). Bacteroidetes phylum was found to be second abundant in S1 and S2 site, whereas Actinobacteria was second dominant in sampling site S3. Enterobacteriaceae family was dominant in site S1, whereas Comamonadaceae and Pseudomonadaceae was abundant in sites S2 and S3 respectively. The Baner possesses an abundant bacterial profile that holds great promise for developing bioremediation tactics against a variety of harmful substances. ConclusionBaner river’s metagenomic analysis offers the first insight into the microbial profile of this hilly stream. Proteobacteria was found to be the most abundant phylum in all the sampling sites indicating anthropogenic interference and sewage contamination. The highest abundance of proteobacteria at S3 reveals it to be the most polluted site, as it is the last sampling site downstream of the area under investigation, and falls after crossing the main city, so more human intervention and pollution were observed. Despite some pathogens, a rich profile of bacteria involved in bioremediation, xenobiotic degradation, and beneficial fish probiotics was observed, reflecting their potential applications for improving water quality and establishing a healthy aquaculture and fishery section.

Anchialine pool shrimp (Halocaridina rubra) as an indicator of sewage in coastal groundwater ecosystems on the island of Hawai'i.

Groundwater is a primary pathway for wastewater and other pollutants to enter coastal ecosystems worldwide. Sewage associated pathogens, pharmaceuticals, and other emerging contaminants pose potential risks to marine life and human health. Anchialine pool ecosystems and the endemic species they support are at risk and provide an opportunity to sample for presence of contaminants prior to diffusion in the marine environment. In this study, we tested the potential use of nitrogen isotopes in the tissues of a dominant anchialine pool grazing shrimp (Halocaridina rubra), as a bioindicator for sewage in groundwater flowing through their habitats. Water quality parameters and shrimp tissue isotopes (N and C) were collected from pools exposed to a range of sewage contamination along the West Hawai'i coastal corridor from 2015 to 2017. Data were used to test for spatial and temporal variability both within and among pools and to examine the relationship between stable isotopes and water quality parameters. Within 22 pools, mean δ15N from whole tissue samples ranged between 2.74‰ and 22.46‰. Variability of isotope values was low within individual pools and within pool clusters. However, δ15N differed significantly between areas and indicated that sewage is entering groundwater in some of the sampled locations. The significant positive relationship between δ15N and dissolved nitrogen (p<0.001, R2 = 0.84) and δ15N and phosphorus (p<0.001, R2 = 0.9) support this conclusion. In a mesocosm experiment, the nitrogen half-life for H. rubra tissue was estimated to be 20.4 days, demonstrating that the grazer provides a time-integrative sample compared to grab-sample measurements of dissolved nutrients. Ubiquitous grazers such as H. rubra may prove a useful and cost-effective method for δ15N detection of sewage in conjunction with standard monitoring methods, enabling sampling of a large number of pools to establish and refine monitoring programs, especially because anchialine habitats typically support no macroalgae.

Comparison of antibiotic-resistant Escherichia coli and extra-intestinal pathogenic E. coli from main river basins under different levels of the sewer system development

Antimicrobial-resistant Escherichia coli in the aquatic environments is considered a strong indicator of sewage or animal waste contamination and antibiotic pollution. Sewer construction and wastewater treatment plant (WWTP) infrastructure may serve as concentrated point sources of contamination of antibiotic-resistant bacteria and antibiotic resistance genes. In this study, we focused on the distribution of antimicrobial-resistant E. coli in two rivers with large drainage areas and different urbanisation levels. E. coli from Kaoping River with drainage mainly from livestock farming had higher resistance to antibiotics (e.g. penicillins, tetracyclines, phenicols, aminoglycosides, and sulpha drugs) and presented more positive detection of antibiotic-resistance genes (e.g. ampC, blaTEM, tetA, and cmlA1) than that from Tamsui River. In Kaoping River with a lower percentage of sewer construction nearby (0–30%) in contrast to a higher percentage of sewer construction (55–92%) in Tamsui River, antimicrobial-resistant E. coli distribution was related to livestock farming waste. In Tamsui River, antimicrobial resistant E. coli isolates were found more frequently in the downstream drainage area of WWTPs with secondary water treatment than that of WWTPs with tertiary water treatment. The Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR showed that the fingerprinting group was significantly related to the sampling site (p < 0.01) and sampling date (p < 0.05). By utilising ERIC-PCR in conjunction with antibiotic susceptibility and antibiotic-resistance gene detection, the relationship among different strains of E. coli could be elucidated. Furthermore, we identified the presence of six extra-intestinal pathogenic E. coli isolates and antibiotic-resistant E. coli isolates near drinking water sources, posing a potential risk to public health through community transmission. In conclusion, this study identified environmental factors related to antibiotic-resistant bacteria and antibiotic-resistance gene contamination in rivers during urban development. The results facilitate the understanding of specific management of different waste streams across different urban areas. Periodic surveillance of the effects of WWTPs and livestock waste containing antibiotic-resistant bacteria and antibiotic-resistance genes on river contamination is necessary.

Tracking contaminants of concern in wet-weather sanitary sewer overflows

Four representative sites in the greater city of Sydney, Australia, were selected for a study of the wet-weather overflow of sanitary (separate to stormwater) sewerage systems. Water samples were collected by autosamplers from up to eight wet weather overflow events over 16 months and from companion receiving water sites. The objective was to identify the risks posed by sewage contaminants to aquatic biota in the receiving waters, to aid in prioritising management actions. Twelve organic contaminants were identified in influents across the four sites under rainfall ingress diluted conditions, with measurements showing that the highest concentrations were restricted to the anti-inflammatory acetaminophen and the diabetes medication metformin. Lesser contaminants included theobromine, ibuprofen, sucralose, and three benzotriazoles (mainly 1-H benzotriazole). An assessment of the toxicity of the identified organic chemicals indicated that none appeared to pose concerns for ecosystem health before wet-weather ingress dilution, and this was even less likely after dilution in the receiving waters. Metal concentrations were low; however, ammonia concentrations in the influent did pose a risk to ecosystem health, although receiving water dilution diminished this risk at four of the five receiving water locations studied.

Using Statistical Analysis to Assess Shallow Groundwater Quality in Squatter Settlement of Dar es Salaam and Pwani Regions in Tanzania

In Dar es Salaam and the Coastal regions, groundwater is the primary source of freshwater. Urbanization, industrialization, and agricultural activities have all contributed to the overuse of this resource, resulting in a decline in quality. In this study, we employ statistical analysis as a means to improve our understanding on groundwater quality. Seventy-one groundwater samples in squatter areas of Dar es Salaam and Coastal regions were used with 10 chemical parameters. Based on their dominant chemical compositions, hierarchical cluster analysis (HCA) classified samples into three main clusters. The clusters were then characterized with the help of the results from principal component analysis (PCA), Pearson's correlation coefficient of the chemical variables and piper diagrams. Cluster one was characterized by high salinity as a result of seawater intrusion. Cluster two was characterized by an intermediate salinity and high contamination. This was a result of sewage contamination and a moderate effect of seawater intrusion. With a low level of salinity and contamination, cluster three was found to be suitable for human consumption. The information obtained from this study demonstrates that the quality of the water has declined in some areas within the chosen regions. Therefore, prompt action is required to prevent further deterioration to the aquifers in the region.

Demystifying the decadal shift in the extent of groundwater in the coastal aquifers of Gujarat, India: A case of reduced extent but increased magnitude of seawater intrusion

Catastrophic increase in urbanisation and industrialisation along the coastal region leads to increased stress on groundwater reservoirs worldwide. As a growing economy, India faces extreme water crises due to rising water demand and escalating salinisation, specifically in the coastal districts. Therefore, this study shows the implication of a comprehensive modelling approach to assess the spatiotemporal changes in hydrogeochemical processes in the coastal aquifer of the Surat district. Using a multi-model assessment approach, the present study focuses on the decadal evolution in groundwater quality of the coastal aquifers of Surat, Gujarat. Fifty-one groundwater samples were collected for 2008, 2012, and 2018 to assess the spatio-temporal shift in groundwater quality. Piper diagram revealed a shift of hydrogeochemical facies from Mg2+-HCO3− type to Ca2+-Mg2+-Cl− type, indicating the increased salinisation over a decade. The result suggests that rock-water interaction, seawater intrusion mechanism, and anthropogenic activities (intensive agricultural activities and improper waste management) govern the hydrogeochemical processes in the coastal aquifer. A shift of dominance of carbonate weathering to silicate weathering with the dissolution of calcite, dolomite, and gypsum, changing the hydrogeochemistry, was observed over the last decades. This shift leads to the increasing hardness of groundwater. The enrichment of nutrients in groundwater during 2018 (NO3− = 2 to 85 mg. L−1) compared to 2008 (NO3− = 1 to 36 mg.L−1) indicates the increasing imprints of agricultural fertilizer application and human organic waste through sewage contamination on the coastal aquifer. The seawater mixing index model demonstrates that extent of seawater intrusion reduced in 2018 compared to 2012, but the magnitude increased near the coastal talukas (SMI =9.5). The present study helps to understand the increasing anthropogenic activities over a decade leading to increased salinisation and groundwater contamination in the aquifer system. This work can help local stakeholders, water resource managers, and the state government manage the groundwater resources and the future potential threat of aquifer contamination.

Bacteriological Assessment of Fecal Contamination in the Sediments of the Gulf of Annaba (Southern Mediterranean): A Preliminary Investigation

This study investigated the bacteriological and physicochemical quality of seawater and sediment samples collected from four sampling sites in the Gulf of Annaba (Northeastern Algeria) over a one-year period. Culture-based techniques were used to quantify and assess Fecal Indicator Bacteria (FIB) and potentially pathogenic bacteria. Additionally, various physicochemical parameters including temperature, pH, salinity, dissolved oxygen, and suspended solids were measured. The results revealed seasonal variations in the physicochemical variables, reflecting the influence of environmental conditions in the research area. The highest concentrations of FIB were observed in samples obtained from Sidi Salem and Rezgui Rachid, indicating a possible association with sewage contamination. Furthermore, the sediments collected from all sites exhibited higher levels of FIB and potentially pathogenic bacteria compared to the seawater samples, particularly during the summer and fall seasons.

Environmental assessment of sewage contamination in the surroundings of a marine outfall combining human mastadenovirus and fecal indicator bacteria

This study assessed the microbiological contamination of the marine area of a metropolitan region, where a marine outfall is used as a sanitary solution for domestic sewage. For human mastadenovirus (HAdV) quantification 134 water samples were concentrated by skimmed milk flocculation method and analyzed with qPCR and PMAxx-qPCR, being the latter to assess the capsid integrity viral. HAdV with intact capsids were detected in 10 % (16/102) of samples classified as suitable for bathing using at least one fecal bacterial indicator. Spatial analysis of the results showed that the drainage channels of the basin that flow into the sea are the main sources of microbiological contamination in the foreshore zone, where intact HAdV reached a concentration of up to 3 log genomic copies/L. HAdV serotypes A12, D, F40 and F41 were characterized. Our results suggest the use of intact HAdV as a complementary parameter to assess the quality of recreational waters.

Modeled predictions of human-associated and fecal-indicator bacteria concentrations and loadings in the Menomonee River, Wisconsin using in-situ optical sensors.

Human sewage contamination of waterways is a major issue in the United States and throughout the world. Models were developed for estimation of two human-associated fecal-indicator and three general fecal-indicator bacteria (HIB and FIB) using in situ optical field-sensor data for estimating concentrations and loads of HIB and FIB and the extent of sewage contamination in the Menomonee River in Milwaukee, Wisconsin. Three commercially available optical sensor platforms were installed into an unfiltered custom-designed flow-through system along with a refrigerated automatic sampler at the Menomonee River sampling location. Ten-minute optical sensor measurements were made from November 2017 to December 2018 along with the collection of 153 flow-weighted discrete water samples (samples) for HIB, FIB, dissolved organic carbon (DOC), and optical properties of water. Of those 153 samples, 119 samples were from event-runoff periods, and 34 were collected during low-flow periods. Of the 119 event-runoff samples, 43 samples were from event-runoff combined sewer overflow (CSO) influenced periods (event-CSO periods). Models included optical sensor measurements as explanatory variables with a seasonal variable as an interaction term. In some cases, separate models for event-CSO periods and non CSO-periods generally improved model performance, as compared to using all the data combined for estimates of FIB and HIB. Therefore, the CSO and non-CSO models were used in final estimations for CSO and non-CSO time periods, respectively. Estimated continuous concentrations for all bacteria markers varied over six orders of magnitude during the study period. The greatest concentrations, loads, and proportion of sewage contamination occurred during event-runoff and event-CSO periods. Comparison to water quality standards and microbial risk assessment benchmarks indicated that estimated bacteria levels exceeded recreational water quality criteria between 34 and 96% of the entire monitoring period, highlighting the benefits of high-frequency monitoring compared to traditional grab sample collection. The application of optical sensors for estimation of HIB and FIB markers provided a thorough assessment of bacterial presence and human health risk in the Menomonee River.

Insights about levels and sources of organic pollution in an urbanized Amazon estuary (Belém, PA, Northern Brazil)

Amazon aquatic systems have been affected by organic pollution from urbanized regions. This study was conducted to determine the levels, sources, and distribution patterns of 16 polycyclic aromatic hydrocarbons (PAHs) and 6 steroid markers in surficial sediments from an important urbanized Amazon estuarine system (Belém, PA, Northern Brazil). Total PAH concentration (∑PAH) ranged from 878.2 to 9905.7ngg-1, 3295.2ngg-1 on average, suggesting a highly contaminated environment. PAH molecular ratios and statistical analysis indicated that PAH originated from a mixture of local sources emissions, mainly related to the combustion of fossil fuels and biomass. Coprostanol levels (maximum concentration = 292.52ngg-1) could be compared to the mid-range reported in the literature. Studied stations, except for one, presented sterol ratio data indicating organic matter related to untreated sewage. Sterols indicative of sewage contamination showed a correlation with pyrogenic PAH amounts which are transported by the same channels where sewage is discharged.

Lateral distribution, environmental occurrence, and assessment of organic pollutants in surface sediments of the East Malaysia.

One of the molecular chemical markers used to identify anthropogenic inputs is linear alkylbenzenes (LABs) that cause serious impacts in the bays and coastal ecosystems. The surface sediments samples collected from the East Malaysia, including Brunei bay to estimate the LABs concentration and distribution as molecular markers of anthropogenic indicators. Gas chromatography-mass spectrometry (GC-MS) was used after purification, fractionation the hydrocarbons in the sediment samples to identify the sources of LABs. The analysis of variance (ANOVA) and Pearson correlation coefficient were applied to analyze the difference between sampling stations' significance at p < 0.05. Long to short chains L/S, homologs C13/C12, and internal to external (I/E) congeners have used to assess the LABs degradation rates as well as the effectiveness of sewage treatment. Results of this study showed that the LABs concentration ranged between 7.1 to 41.3ngg-1 dw, in the investigated stations. The majority of sample sites exhibited a considerable input of C13-LABs homologs, and LABs homologs differed significantly. The estimated LABs ratios (I/E), which ranged between 0.6 and 2.2, demonstrated the effluents with primary and less secondary sources are released into the bay waters. The degradation of LABs were up to 42% in the interrogated locations. The conclusion is that the wastewater treatment system needs to be improved, and that LABs molecular markers are highly effective in tracing anthropogenic sewage contamination.