Development of a PCR protocol for the detection of Escherichia coli O157:H7 and Salmonella spp. in surface water

Escherichia coli O157:H7 and Salmonella are pathogenic microorganisms that can cause severe gastrointestinal illness in humans. These pathogens may be transmitted in a variety of ways, including food and water. The presence of Salmonella and E. coli O157:H7 in surface waters constitutes a potential threat to human health when used for either drinking or recreation. As with most waterborne pathogens, Salmonella and E. coli O157:H7 are difficult to detect and enumerate with accuracy in surface waters due to methodological limitations. The aim of this study was to develop a protocol for the detection of Salmonella spp., E. coli O157:H7 and E. coli virulence genes (stx ₁, stx ₂ and eae) in water using a single enrichment step and PCR. In spiked water samples, PCR results showed high sensitivity (<3 CFU/L) for both microorganisms. The protocol developed in this study has been applied in different surface waters in association with microbiological and physical analysis. The frequency of PCR positive samples was 33% for Salmonella and 2% for E. coli O157:H7 producing intimin (eae) and Shiga-like toxin I (stx ₁). Moreover, the finding of amplicons corresponding to eae and stx ₁ genes in the absence of E. coli O157:H7 suggested the possible presence of other pathogenic bacteria that carry these genes (e.g. EHEC, Shigella strains). The results obtained showed that the developed protocol could be applied as a routine analysis of surface water for the evaluation of microbiological risks.     

Multi-residue analysis of fifty pesticides in river waters and in wastewaters

Environmental Science and Pollution Research - Three sampling campaigns were performed in the Lis River (Leiria, Portugal) in February of 2018, November of 2018, and May of 2019. River water and...     

Niagara region farmers' markets: local food systems and sustainability considerations

This article presents the findings of a survey of farmers' markets customers in the Niagara region of Ontario, Canada. The recent growth of farmers' markets in North America and the association of these markets with local food systems development provoke examination to gain insights into consumer motivations for patronizing these markets, and to then reflect on their potential role within locally oriented and sustainable food production systems. The survey carried out on customers of three Niagara region farmers' markets corroborates previous studies that noted that socioeconomic and cultural factors such as the importance of food freshness, support of local farmers and the local farm economy, and social interaction—embeddedness—are key expressions of people's support and interest in farmers' markets. This work serves to heighten our understanding of consumer attitudes toward direct marketing via farmers' markets, yields useful speculation about these markets and their roles in sustainable local food systems progress, and also raises critical questions about such customer patronage and associated farmers' markets potential in local food system development.     

Well-being for all? The social distribution of benefits gained from woodlands and forests in Britain

Well-being is a positive physical, mental and social state and has increasingly become an area of interest to researchers and policy-makers internationally. This paper presents results from research that analyses the well-being benefits gained by different sections of society through viewing, engaging with, and accessing woodlands and forests in Britain. We draw on 31 studies undertaken since 2001 and present a meta-analysis of quantitative data and a meta-synthesis of qualitative data to explore the range of benefits and associated activities in woodlands, and their social distribution. We also present a state-of-the-art typology of well-being benefits for woodlands in Britain. The findings illustrate the wide range of well-being benefits gained by different social groups through various forms of engagement with and activities undertaken in woodlands. We illustrate the wide range of meanings and values attached to trees and woodlands across different social groups. The evidence also illustrates how carefully designed and targeted interventions can be particularly effective in enabling and encouraging people to visit woodland sites, to participate or get involved in new activities and, therefore, to realise a range of well-being benefits.     

Living without buffers—illustrating climate vulnerability in the Lake Victoria basin

Exposure, sensitivity and adaptive capacity are essential, albeit theoretically vague, components of climate vulnerability. This has triggered debate surrounding how these factors can be translated into, and understood in, an empirical context subject to present and future harm. In this article, which draws on extensive fieldwork in the Lake Victoria Basin of Kenya and Tanzania, we illustrate how exposure, sensitivity and adaptive capacity play out in the context of climate vulnerability and discuss how they interact in situ. Using a mixed methods approach including survey data, rainfall data and a suite of participatory methods, such as focus groups and interactive mapping of seasonal calendars, we identify how climate-induced stressors affect smallholder farmers’ well-being and natural resources. Drawing on the seasonal calendar as a heuristic, and climate vulnerability terminology, we illustrate when, where and how these climate-induced stressors converge to constrain farmers’ livelihoods. Our analysis indicates that farmers in the basin face a highly uncertain future with discernible, but differentiated, adaptation deficits due to recurring, and potentially worsening, patterns of hardship.     

Beyond water data: benefits to volunteers and to local water from a citizen science program

Survey results of citizen science water data collection volunteers are presented, indicating personal benefits (e.g., being in nature, helping local water quality), and suggesting potential long-term benefits of improved watershed health (e.g., behavior change). These results can inform citizen science program development and contribute to watershed planners’ understanding of the broad benefits of such programs. We suggest that respondents’ positive feelings toward the watershed's major river and desire to learn about science and nature are place-specific elements that watershed and citizen science program managers could utilize in program development. Moreover, we explore the potential of social diffusion and behavior change and suggest the need for further research in these areas. We conclude that citizen science has potential not just as a means to collect large amounts of data (cheaply), but as a means to engage citizens to make environmentally friendly decisions.     

Polychlorinated biphenyls and omega-3 fatty acid exposure from fish consumption, and thyroid cancer among New York anglers

Fish from the Great Lakes contain polychlorinated biphenyls(PCBs)which have been shown to disrupt endocrine function and mimic thyroid hormones,but they also contain beneficial omega-3 fatty acids that may offer protection against endocrine cancers.The purpose of this study was to examine the effects of Lake Ontario fish consumption and the estimated consumption of PCBs and omega-3 fatty acids on the risk of thyroid cancer in a group of sport fishermen.Anglers from the New York State Angler Cohort Study were followed for cancer incidence from 1991–2008.Twenty-seven cases of incident thyroid cancer and 108 controls were included in the analyses.Total estimated fish consumption,estimated omega-3 fatty acid consumption,and estimated PCB consumption from Lake Ontario fish were examined for an association with the incidence of thyroid cancer,while matching on sex,and controlling for age and smoking status.Results from logistic regression indicate no significant associations between fish consumption,short-term estimated omega-3 fatty acids,or estimated PCB consumption from Great Lakes fish and the development of thyroid cancer,but it was suggested that long-term omega-3 fatty acid from Great Lakes fish may be protective of the development of thyroid cancer.In conclusion,fish consumption,with the possible concomitant PCBs,from the Great Lakes does not appear to increase the risk of thyroid cancer in New York anglers.Further research is needed in order to separate the individual health effects of PCBs from omega-3 fatty acids contained within the fish.     

Effects of travel mode on exposures to particulate air pollution

Monitoring was carried out of particulate concentrations whilst simultaneously walking and driving 48 routes in London, UK. Monitoring was undertaken during May and June 2005. Route lengths ranged from 601 to 1351 m, and most routes were travelled in both directions. Individual journey times ranged from 1.5 to 15 min by car (average 3.7 min) and 7.3 to 30 min (average 12.8 min) whilst walking; car trips were therefore repeated up to 5 times for each single walking trip and the results averaged for the route. Car trips were made with windows closed and the ventilation system on a moderate setting. Results show that mean exposures while walking are greatly in excess of those while driving, by a factor 4.7 for the coarse particle mass (PM10-PM2.5), 2.2 for the fine particle mass (PM2.5-PM1), 1.9 for the very fine particle mass (相似文献   

Quantification and composition of pharmaceutical waste in New Zealand

Journal of Material Cycles and Waste Management - This study aimed to quantify the amount of pharmaceutical waste produced in New Zealand, and determine the composition of pharmaceutical waste from...     

Persistent Detection of Cosavirus and Saffold Cardiovirus in Riachuelo River,Argentina

Food and Environmental Virology - Cosaviruses (CoSV) and Saffold cardiovirus (SAFV) are novel members of the Picornaviridae family. The Matanza-Riachuelo river basin covers a total area of 2200 km2...