scholarly journals Microbial water quality at contrasting recreational areas in a mixed-use watershed in eastern Canada

Author(s):  
Ainslie J. Butler ◽  
Katarina Pintar ◽  
Janis L. Thomas ◽  
Manon Fleury ◽  
Stefanie Kadykalo ◽  
...  

Abstract Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible.

2008 ◽  
Vol 71 (7) ◽  
pp. 1427-1433 ◽  
Author(s):  
JAMES A. LOWTHER ◽  
KATHLEEN HENSHILWOOD ◽  
DAVID N. LEES

The human health risk associated with the consumption of molluscan shellfish grown in sewage-contaminated waters is well established. Noroviruses, which cause gastroenteritis, are the principal agents of shellfish-related illness. Fecal-indicator quality standards based on Escherichia coli are well established in Europe and elsewhere. However, norovirus outbreaks after consumption of shellfish meeting these standards still occur, and the need to improve consumer health protection is well recognized. Alternative approaches proposed include direct monitoring of viral pathogens and the use of alternative indicator organisms capable of providing a better indication of virus risk. This study applies a recently developed TaqMan PCR assay to assess norovirus contamination in shellfish. Comparison was made with E. coli as the existing sanitary standard and a male-specific RNA bacteriophage as a possible alternative. Two commercial pacific oyster (Crassostrea gigas) harvesting areas were monitored over a 31-month period. The results show peaks of norovirus contamination in both areas during winter months, with average levels approximately 17 times higher in oysters sampled October to March than during the remainder of the year, consistent with epidemiological data for the United Kingdom showing oyster-associated illness is confined to winter months. While there was no apparent association with E. coli, an association between levels of norovirus contamination and the male-specific RNA bacteriophage was noted, with average norovirus levels over 40 times higher in samples with male-specific RNA bacteriophage counts of >1,000 PFU/100 g than in samples with <100 PFU/100 g. Overall, these results suggest that norovirus monitoring in shellfish production areas could be an effective strategy for reduction of virus risk.


Author(s):  
Helena M. Solo-Gabriele ◽  
Valerie J. Harwood ◽  
David Kay ◽  
Roger S. Fujioka ◽  
Michael J. Sadowsky ◽  
...  

Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.


2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alex Saturday ◽  
Thomas J. Lyimo ◽  
John Machiwa ◽  
Siajali Pamba

AbstractBackground Microbial water quality serves to indicate health risks associated with the consumption of contaminated water. Nevertheless, little is known about the microbiological characteristics of water in Lake Bunyonyi. This study was therefore undertaken to examine the spatial and temporal variations of faecal indicator bacteria (FIB) in relation to physicochemical parameters in Lake Bunyonyi. Result The FIB concentration was consistently measured during sampling months and correlated with each other showing the presumed human faecal pollution in the lake. The highest concentration values for E. coli (64.7 ± 47.3 CFU/100 mL) and enterococci (24.6 ± 32.4 CFU/100 mL were obtained in the station close to the Mugyera trading centre. On a temporal basis, the maximum values were recorded during the rainy season in October 2019 (70.7 ± 56.5 CFU/100 mL for E. coli and 38.44 ± 31.8 CFU/100 mL for enterococci. FIB did not differ significantly among the study stations (p > 0.05) but showed significant temporal variations among the months (p < 0.05) with concentrations being significantly high in wet season than dry season (U = 794, p < 0.0001 for E. coli; U = 993.5, p = 0.008 for enterococci). Spearman’s rank correlation revealed that FIB concentrations were significantly positively correlated with turbidity and DO concentration levels (p < 0.05). Approximately 97.2% of the water samples had E. coli and enterococci concentrations levels below USEPA threshold for recreational waters. Likewise, 98.1 and 90.7% of samples recorded E. coli and enterococci counts exceeding the UNBS, APHA, WHO and EU threshold values for drinking water. Conclusion The FIB counts show that the Lake Bunyonyi water is bacteriologically unsuitable for drinking unless it is treated since the FIB pose health risks to consumers. Besides, the water can be used for recreational purposes.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 678
Author(s):  
Kai Zhang ◽  
XiaoNan Li ◽  
ZhenYu Song ◽  
JiaYu Yan ◽  
MengYue Chen ◽  
...  

Cadmium (Cd) is a highly carcinogenic metal that plays an important role in the risk management of soil pollution. In this study, 153 soil samples were collected from a coal chemical plant in northwest China, and the human health risks associated with Cd were assessed through multiple exposure pathways. Meanwhile, by the Kriging interpolation method, the spatial distribution and health risks of Cd were explored. The results showed that the average concentration of Cd in the soil was 0.540 mg/kg, which was 4.821 and 5.567 times that of the soil background value in Ningxia and China, respectively. In comparison, the concentration of Cd in the soil was below the national soil environmental quality three-level standard (1.0 mg/kg). In addition, health risk assessment results showed that the total carcinogenic risk of Cd was 1.269 × 10−6–2.189 × 10−6, both above the acceptable criteria (1 × 10−6), while the hazard quotient was within the acceptable level. Oral intake and ingestion of soil particles were the main routes of exposure, and the carcinogenic risk control value of oral intake was the lowest (0.392 mg/kg), which could be selected as the strict reference of the safety threshold for Cd in the coal chemical soil. From Kriging, a prediction map can be centrally predicted on heavy metal pollution in the area surrounding the coal entrance corridor and pedestrian entrance. This study can provide a theoretical basis for the determination of the heavy metal safety threshold of the coal chemical industry in China.


2021 ◽  
Vol 8 (1) ◽  
pp. 1-5
Author(s):  
Nahla S El-Shenawy ◽  
Heba N Gad EL-Hak ◽  
Mahi A Ghobashy ◽  
Maha FM Soliman ◽  
Farida A Mansour ◽  
...  

Accumulation of heavy metals in fish is considered a critical problem for human health. Therefore, the study aimed to quantify the concentrations of iron (Fe), zinc (Zn), manganese (Mn), and lead (Pb) in Oreochromis niloticus and Clarias gariepinus from two areas in Al Sharqia governorate, Egypt, from September 2017 to August 2018. A human health risk assessment was conducted to evaluate the potential hazards associated with fish consumption. Metals concentrations (mg/kg dry weight) in muscles of catfish ranged 1.88-221.26 for Fe; 1.78-19.77 for Zn; BDL-238.51 for Mn; BDL-22.75 for Pb. In muscles of tilapia fish metals concentrations ranged 7.96-149.10 for Fe; 1.20-19.77 for Zn; BDL-230.82 for Mn; BDL-25.93 for Pb. Pb had Hazard quotients (HQs) which indicated potential health risks to tilapia consumers at both study areas and catfish consumers at the Faqous area. Fishermen were at higher risk compared to the other consumers.


Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1307
Author(s):  
Jin-Young Choi ◽  
Hyeryeong Jeong ◽  
Kongtae Ra ◽  
Kyung-Tae Kim

Road and industrial origin particulate matters (PM) are a significant source of potentially toxic elements (PTEs), with health risks to the surrounding residents. In Korea for 60 years, although industries, roads and automobiles have increased aggressively, there are still few PTEs data in PM in road-deposited sediment (RDS) of industrial complexes (ICs). Therefore, this study aimed to investigate the PTE composition of on-road PM10 from nine major ICs and its pollution degree in Korea and evaluate its human health risks. The geo-accumulation index (Igeo) and pollution load index (PLI) elucidated that on-road PM10 were severely polluted by Sb, Zn, Ag and Pb. A combination of principal component analysis (PCA) and chemical tracers was used to define the PTEs sources. The results showed that non-exhaust emission from vehicles’ activity is the primary source of PTEs in on-road PM10, and industrial emissions are the secondary source. The riskiest pathway on carcinogenic and non-carcinogenic by on-road PM10 with PTEs was in-gestion. Traffic origin PTEs including Pb, As, Sb and Cd had a more significant impact on carcinogenic and non-carcinogenic health than those of industrial origins. These results could help mitigate public health risks arising from on-road PM10 and improve air quality in ICs.


2009 ◽  
Vol 75 (21) ◽  
pp. 6736-6744 ◽  
Author(s):  
Karen St-Pierre ◽  
Simon Lévesque ◽  
Eric Frost ◽  
Nathalie Carrier ◽  
Robert D. Arbeit ◽  
...  

ABSTRACT This study aimed to assess the importance of quantitatively detecting Campylobacter spp. in environmental surface water. The prevalence and the quantity of Campylobacter spp., thermotolerant coliforms, and Escherichia coli in 2,471 samples collected weekly, over a 2-year period, from 13 rivers and 12 streams in the Eastern Townships, Québec, Canada, were determined. Overall, 1,071 (43%), 1,481 (60%), and 1,463 (59%) samples were positive for Campylobacter spp., thermotolerant coliforms, and E. coli, respectively. There were weak correlations between the weekly distributions of Campylobacter spp. and thermotolerant coliforms (Spearman's ρ coefficient = 0.27; P = 0.008) and between the quantitative levels of the two classes of organisms (Kendall tau-b correlation coefficient = 0.233; P < 0.0001). Well water samples from the Eastern Townships were also tested. Five (10%) of 53 samples from private surface wells were positive for Campylobacter jejuni, of which only 2 were positive for thermotolerant coliforms. These findings suggest that microbial monitoring of raw water by using only fecal indicator organisms is not sufficient for assessing the occurrence or the load of thermophilic Campylobacter spp. Insights into the role of environmental water as sources for sporadic Campylobacter infection will require genus-specific monitoring techniques.


Author(s):  
Mahbubul Siddiqee ◽  
Rebekah Henry ◽  
Rebecca Coulthard ◽  
Christelle Schang ◽  
Richard Williamson ◽  
...  

Estuarine bank sediments have the potential to support the survival and growth of fecal indicator organisms, including Escherichia coli. However, survival of fecal pathogens in estuarine sediments is not well researched and therefore remains a significant knowledge gap regarding public health risks in estuaries. In this study, simultaneous survival of Escherichia coli and a fecal pathogen, Salmonella enterica serovar Typhimurium, was studied for 21 days in estuarine bank sediment microcosms. Observed growth patterns for both organisms were comparable under four simulated scenarios; for continuous-desiccation, extended-desiccation, periodic-inundation, and continuous-inundation systems, logarithmic decay coefficients were 1.54/day, 1.51/day, 0.14/day, and 0.20/day, respectively, for E. coli, and 1.72/day, 1.64/day, 0.21/day, and 0.24/day for S. Typhimurium. Re-wetting of continuous-desiccated systems resulted in potential re-growth, suggesting survival under moisture-limited conditions. Key findings from this study include: (i) Bank sediments can potentially support human pathogens (S. Typhimurium), (ii) inundation levels influence the survival of fecal bacteria in estuarine bank sediments, and (iii) comparable survival rates of S. Typhimurium and E. coli implies the latter could be a reliable fecal indicator in urban estuaries. The results from this study will help select suitable monitoring and management strategies for safer recreational activities in urban estuaries.


2010 ◽  
Vol 44 (16) ◽  
pp. 4674-4691 ◽  
Author(s):  
Jeffrey A. Soller ◽  
Mary E. Schoen ◽  
Timothy Bartrand ◽  
John E. Ravenscroft ◽  
Nicholas J. Ashbolt

Author(s):  
Dragana Pavlović ◽  
Marija Pavlović ◽  
Veljko Perović ◽  
Zorana Mataruga ◽  
Dragan Čakmak ◽  
...  

The primary focus of this research was the chemical fractionation of potentially toxic elements (PTEs) and their presence in several industrialised cities in Serbia. Furthermore, their origin, contamination levels, and environmental and human health risks were assessed. The results indicated that the examined soils were characterised by slightly higher Cu, Ni, Pb, and Zn levels than those set by European and national regulations. These elevated Cu, Pb, and Zn concentrations were caused by intensive traffic and proximity to industry, whereas the higher Ni levels were a result of the specific geological substrate of the soil in the study area. The environmental risk was found to be low and there was no enrichment/contamination of the soil with these elements, except in the case of Pb, for which moderate to significant enrichment was found. Lead also poses a potential non-carcinogenic risk to children through ingestion and requires special attention due to the fact that a significant proportion of this element was present in the tested soil samples in a potentially available form. Analysis of the health risks showed that children are more at risk than adults from contaminants and that ingestion is the riskiest exposure route. The carcinogenic risk was within the acceptable limits.


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