Accumulation of perfluoroalkyl substances in lysimeter-grown rice in Japan using tap water and simulated contaminated water

Chemosphere ◽  
2019 ◽  
Vol 231 ◽  
pp. 502-509 ◽  
Author(s):  
Eriko Yamazaki ◽  
Sachi Taniyasu ◽  
Kosuke Noborio ◽  
Heesoo Eun ◽  
Pooja Thaker ◽  
...  
Keyword(s):  
Tap Water ◽  
Perfluoroalkyl Substances ◽  
Contaminated Water

Transfer of Escherichia coli O157:H7 to Romaine Lettuce due to Contact Water from Melting Ice

2008 ◽  
Vol 71 (2) ◽  
pp. 252-256 ◽  
Author(s):  
JIN KYUNG KIM ◽  
MARK A. HARRISON
Keyword(s):  
Escherichia Coli ◽  
Tap Water ◽  
Sampling Site ◽  
Contaminated Water ◽  
Escherichia Coli O157 ◽  
Romaine Lettuce ◽  
E Coli ◽  
Ice Melt ◽  
Leaf Surfaces ◽  
Shipping Containers

Ice can be used to chill romaine lettuce and maintain relative humidity during transportation. Escherichia coli O157:H7 may contaminate water used for ice. The objective of this study was to determine the potential for E. coli O157:H7 contamination of romaine lettuce from either ice contaminated with the pathogen or by transfer from lettuce surfaces via melting ice. In experiment 1, lettuce was spot inoculated with E. coli O157:H7 and chilled with ice prepared from uncontaminated tap water. In experiment 2, water inoculated with this pathogen was frozen and used to ice lettuce. Three heads of lettuce were stacked in each container and stored at 4 or 20°C. After the ice melted, E. coli O157:H7 attachment to and recovery from the lettuce leaves were determined. For experiment 1, the population of E. coli O157:H7 attached to inoculated sites averaged 3.8 and 5.5 CFU/cm2 at 4 and 20°C, respectively. Most of the uninoculated sites became contaminated with the pathogen due to ice melt. For experiment 2, 3.5 to 3.8 log CFU E. coli O157:H7 per cm2 was attached to the top leaf on the first head. After rinsing with chlorinated water (200 μg/ml), E. coli O157:H7 remained on the surface of the top head (1.8 to 2.0 log CFU/cm2). There was no difference in numbers of E. coli O157:H7 recovered from each sampling site at 4 and 20°C. Results show that E. coli O157:H7 can be transferred onto other produce layers in shipping containers from melted ice made of contaminated water and from contaminated to uncontaminated leaf surfaces.

scholarly journals Spectrophotometric Analysis of Chromium (VI) Levels in Varying Arizona County Water Samples used to Determine which County Water Contains the Most Toxicity when Introduced to Yeast

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Madleen Khamisi ◽  
Danielle Falcone ◽  
Christina Bentley ◽  
Pamela Marshall
Keyword(s):  
Cell Count ◽  
Yeast Strain ◽  
Tap Water ◽  
Spectrophotometric Analysis ◽  
Contaminated Water ◽  
Yeast Growth ◽  
Maricopa County ◽  
Average Cell ◽  
Chromium Vi ◽  
Pima County

This study analyzed the Chromium (VI) levels present in three Arizona counties tap water, as represented by the major universities residing within them. Each sample was surveyed using spectrophotometry to determine the contaminant levels of Cr(VI) in the water. Introduction to the yeast strain BY4742 was observed to determine whether the contaminated water dampened culture growth. When compared to the Maximum Contaminant Level (MCL) of 0.1 mg/L set by the EPA, Maricopa County contained 14x the amount allowable at 1.4 mg/L. The samples collected for Coconino County and Pima County also displayed contaminant levels higher than the set MCL at 0.3 mg/L and 0.5 mg/L, respectively. Data collected on yeast growth illustrated that Maricopa County was also the most hindering on yeast growth at an average cell count of 97. However, the chosen yeast strain also demonstrated an apparent resistance to Cr(VI) with an average cell count of 120 cells in the Cr(VI) plate. Due to this strains survival in Cr(VI) contaminated water, our initial hypothesis was rejected. Possible generational studies can be done to observe the toxic effects higher levels of Cr(VI) in drinking water have with regard to organismal growth hindrance and accumulation of the element leading to carcinogenic properties. Additional analysis on what other contaminants lie within Arizona counties can be performed, as well.

Volatilization of Chemicals from Tap Water to Indoor Air from Contaminated Water Used for Showering

1999 ◽  
Vol 33 (14) ◽  
pp. 2321-2327 ◽  
Author(s):  
Jacqueline Moya ◽  
Cynthia Howard-Reed ◽  
Richard L. Corsi
Keyword(s):  
Indoor Air ◽  
Tap Water ◽  
Contaminated Water

Mycobacterium simiaeOutbreak Associated With a Hospital Water Supply

2004 ◽  
Vol 25 (12) ◽  
pp. 1050-1055 ◽  
Author(s):  
Nicholas G. Conger ◽  
Robert J. O'Connell ◽  
Valerie L. Laurel ◽  
Kenneth N. Olivier ◽  
Edward A. Graviss ◽  
...  
Keyword(s):  
Medical Records ◽  
San Antonio ◽  
Tap Water ◽  
Contaminated Water ◽  
Microbiology Laboratory ◽  
Treatment Facility ◽  
Hospital Patients ◽  
Military Treatment Facility ◽  
Mycobacterium Simiae ◽  
Culture Positive

AbstractObjective:Mycobacterium simiaeis found primarily in the southwestern United States, Israel, and Cuba, with tap water as its suspected reservoir. Our institution saw an increase inM. simiaeisolates in 2001. An investigation into possible contaminated water sources was undertaken.Design:Environmental cultures were performed from water taps in the microbiology laboratory, patient rooms, points in the flow of water to the hospital, and patients' homes. Patient and environmentalM. simiaewere compared by PFGE.Setting:Military treatment facility in San Antonio, Texas.Patients:All patients with cultures positive forM. simiaebetween January 2001 and April 2002. Medical records were reviewed.Results:M. simiaewas recovered from water samples from the hospital, patients' home showers, and a well supplying the hospital. A single PFGE clone was predominant among water isolates (9 of 10) and available patient isolates (14 of 19). There was an association between exposure to hospital water and pulmonary samples positive for the clonalM. simiaestrain (P= .0018). Only 3 of 22 culture-positive patients met criteria forM. simiaepulmonary disease. Of them, two had indistinguishableM. simiaestrains from tap water to which they were routinely exposed.Conclusions:This represents an outbreak ofM. simiaecolonization with one nosocomial infection. It is only the second time thatM. simiaehas been recovered from hospital tap water and its first presentation in municipal water. This study raises issues about the need and feasibility of eliminating or avoiding exposure toM. simiaefrom tap water.

scholarly journals Use of a Biological Tracer to Investigate Microbial Aerosols Generated by Heater-Cooler Units

2020 ◽  
Vol 41 (S1) ◽  
pp. s423-s423
Author(s):  
Ginny Moore ◽  
Simon Parks ◽  
Allan Bennett
Keyword(s):  
Tap Water ◽  
High Volume ◽  
Mycobacterial Infection ◽  
Contaminated Water ◽  
Experimental Conditions ◽  
Circulating Water ◽  
The United Kingdom ◽  
Local Decision ◽  
Local Decision Making ◽  
Time Required

Background: A multinational outbreak of Mycobacterium chimaera endocarditis following cardiac surgery has been attributed to the use of heater-cooler units (HCUs) during cardiopulmonary bypass. It is hypothesized that mycobacteria can be transmitted to the surgical site via the aerosolization of contaminated water from within the unit. In the United Kingdom, M. chimaera infections have been linked to 1 specific make and model of HCU, which was shown to generate microbial aerosols when circulating water. The manufacturer has since modified this HCU and claims that the dispersal of aerosols has now been prevented. M. chimaera is a common contaminant of HCUs, regardless of make, model, and manufacturer. To help inform local decision making, hospitals require evidence that this modified HCU and/or alternative heater-cooler systems can reduce the risk of mycobacterial infection by incorporating design features that prevent the generation of microbial aerosols external to the device. The time required to culture M. chimaera means investigations focusing on naturally or artificially contaminated HCUs are problematic. Instead, specialist aerobiological techniques incorporating a nonpathogenic, aerostable, biological tracer (Bacillus atrophaeus) were used to investigate microbial aerosols generated and released from brand-new and ‘upgraded’ HCUs. Methods: 4 HCUs (A–D), supplied directly by the manufacturers, were filled with filtered tap water, and high numbers of B. atrophaeus (109 CFU/L) were added to the tanks. High-volume cyclone samplers were used to sample the air when each HCU was switched off and during different operational phases. Samplers were operated for 5 minutes and the collecting fluid cultured for B. atrophaeus. The number of colonies was converted to CFU per cubic meter of air. Results: Under controlled experimental conditions, HCU-A released a small but significant level of aerosol during operational phases (eg, cooling) that resulted in increased pressure within the tank. The filler flap was identified as the principal area of aerosol release. The circulation of water within HCU-B and HCU-C was shown to generate an aerosol but, when connected to an ‘aerosol collection set,’ this aerosol was not released. However, it is essential that effective and sufficient vacuum is maintained. There was no aerosol release from HCU-D. Conclusions: A specialist in aerobiology using a biological tracer can determine the level of aerosol released from an HCU and its location. However, transmission of M. chimaera could occur via aerosolization of contaminated water, but it is not the only possible route of infection. The efficacy of recommended decontamination procedures must also be assured.Funding: NoneDisclosures: None

scholarly journals Tap Water Contributions to Plasma Concentrations of Poly- and Perfluoroalkyl Substances (PFAS) in a Nationwide Prospective Cohort of U.S. Women

2019 ◽  
Vol 127 (6) ◽  
pp. 067006 ◽  
Author(s):  
Xindi C. Hu ◽  
Andrea K. Tokranov ◽  
Jahred Liddie ◽  
Xianming Zhang ◽  
Philippe Grandjean ◽  
...  
Keyword(s):  
Prospective Cohort ◽  
Tap Water ◽  
Plasma Concentrations ◽  
Perfluoroalkyl Substances

scholarly journals Experimental modeling and optimization for the reduction of hexavalent chromium in aqueous solutions using ascorbic acid

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qammer Zaib ◽  
Hung Suck Park ◽  
Daeseung Kyung
Keyword(s):  
Ascorbic Acid ◽  
Humic Acid ◽  
Aqueous Solutions ◽  
Tap Water ◽  
Hard Water ◽  
Contaminated Water ◽  
Optimal Dosage ◽  
Statistical Experimental Design ◽  
Experimental Parameters ◽  
Acid Dosage

AbstractIn this study, we investigated the reduction of toxic Cr(VI) to less toxic Cr(III) using ascorbic acid in various aqueous solutions: deionized water, synthetic soft water, synthetic hard water, and real tap water. The experiments were performed using a statistical experimental design. Response surface methodology (RSM) was used to correlate Cr(VI) reduction (response variable) with experimental parameters such as initial Cr(VI) concentration, humic acid concentration, and ascorbic acid dosage. The empirical model obtained from the experiments was used to estimate and optimize the quantity of ascorbic acid required for the reduction of ≥ 99% Cr(VI) in water. The optimized dosages of ascorbic acid were predicted and experimentally validated for > 99.5% reduction of Cr(VI) (1, 10, 20, and 100 mg/L) in the solutions. Even a solution containing an initial Cr(VI) concentration of 100 mg/L was reduced in concentration ≥ 99.9% with optimal dosage of ascorbic acid (500 mg/L) in the presence of 20 mg/L humic acid. Moreover, the reaction kinetics (kobs-Cr(VI) = 0.71 mM−1 s−1) were sufficient to reduce the ≥ 99.9% Cr(VI) in 20 min. This study sheds new light on the effect of ascorbic acid on Cr(VI) reduction, and provides knowledge fundamental to optimize treatment of Cr(VI) contaminated water to environmentally acceptable endpoints.

scholarly journals Zoonotic aspects of cryptosporidiosis in Nepal

2013 ◽  
Vol 1 (2) ◽  
pp. 21-26
Author(s):  
Sushil Paudyal ◽  
Swoyam Prakash Shrestha ◽  
Narsingh Mahato
Keyword(s):  
Preventive Measures ◽  
Tap Water ◽  
Epidemiological Studies ◽  
Disease Outbreak ◽  
Chemical Processes ◽  
Contaminated Water ◽  
Wild Animals ◽  
Buffer Zones ◽  
Reservoir Hosts ◽  
Swamp Deer

Cryptosporidiosis is a common protozoal cause of diarrhea in humans and animals in Nepal, acquired by ingestion of oocysts that were excreted in the feces of infected individuals. Contaminated water represents the major source of Cryptosporidium infections for humans and can be transmitted from person-to-person, from animal-to-person, animal-to-animal, by ingestion of contaminated water and food or by contact with contaminated surfaces. Being highly resistant to environmental and chemical processes and representing the only group of pathogen surviving chlorination, it has no effective chemotherapy identified for the treatment which makes cryptosporidiosis a debilitating and persistent disease with high potential of transmission among immune-compromised ones like children and AIDS patients. Ghimire et. al.,(2010) and Feng et. al., (2012) have mentioned potential transmission of the oocyst among humans and animals in Nepal through common niche like river water, tap water sources and also from wild animals through the interaction on buffer zones. Studies have shown prevalence rate of 16 % in Children (Dhakal et. al., 2004), 11% in HIV infected patients (Basnet et. al., 2010); 14% in Calves, 19% in buffaloes and 12.5% in swamp deer in Nepal (Feng et. al., 2012). The persistent shedding of oocysts by reservoir hosts like calves, kids, poultry and wild animals like deer and monkeys possess great threat to the transmission to general public. The epidemiological studies of cryptosporidium and the knowledge of the pattern of the disease outbreak can guide therapy and effective preventive measures against this disease.DOI: http://dx.doi.org/10.3126/ijasbt.v1i2.7959 Int J Appl Sci Biotechnol, Vol. 1(2): 21-26

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