Potential potable-water supplies in Redwood National Park, California

1978 ◽  
Author(s):  
J.P. Akers
1988 ◽  
Vol 20 (11-12) ◽  
pp. 5-10 ◽  
Author(s):  
J. S. Colbourne ◽  
P. J. Dennis ◽  
R. M. Trew ◽  
C. Berry ◽  
G. Vesey

A survey for legionella in public water supplies in England failed to detect culturable L.pneumophila in all but samples from taps in buildings; however, the organism was detected in underground and surface water sources and distribution systems using an indirect immunofluorescent assay (IFA) to L.pneumophila serogroup 1. Culturability was related to water temperatures above 20°C. In water mains L.pneumophila was associated with biofilms or sediment. Non-culturable L.pneumophila detected in potable waters by IFA were recovered by heat shock experiments demonstrating their viability. Although the strain found in potable water is rarely asociated with disease, monoclonal expression, a virulence marker, was altered by heat shock. These findings have implications for the prevention of legionellosis and may explain the sporadic nature of legionnaires disease in the community.


2010 ◽  
Vol 62 (11) ◽  
pp. 2720-2728 ◽  
Author(s):  
Konstantinos C. Makris ◽  
Shane A. Snyder

Cyprus is currently the leading country in antibiotic consumption among all European Union member countries and is likely to have a high consumption of pharmaceuticals overall. This reconnaissance type of project sought to investigate the occurrence of 16 pharmaceuticals, six known or suspected endocrine disrupting compounds (EDCs), two flame retardants, one insect repellant, and one fragrance for the first time in water supplies of Cyprus. Groundwater samples from sites that were located beneath farms scattered around Cyprus, wastewater influent and tertiary-treated effluent, raw and finished surface water, and household potable water samples were analyzed using liquid chromatography and tandem mass spectrometry. Most of the tested compounds were < minimum reporting limit, except for ibuprofen (mean of 1.4 ng L−1) and bisphenol A (mean of 50 ng L−1), which were detected in more than one out of the five groundwater sampling sites. Certain compounds were found in large concentrations in the wastewater influent (caffeine 82,000 ng L−1, sulfamethoxazole 240 ng L−1, ibuprofen 4,300 ng L−1, and triclosan 480 ng L−1). However, several pharmaceuticals and EDCs were detected in the tertiary-treated effluent (recycled water). For the raw and finished surface water, and potable water samples, ibuprofen was detected, whereas, bisphenol-A was measured in only potable water. Overall, with a few notable exceptions, source, finished and potable water had rare detection or low concentration of target compounds, but further research is needed to elucidate the temporal and spatial distribution of the detected emerging contaminants along with the characterization of the related public health risk.


2021 ◽  
Author(s):  
Elliott H. Bussell ◽  
Nik J. Cunniffe

AbstractEpidemics can particularly threaten certain sub-populations. For example, for SARS-CoV-2, the elderly are often preferentially protected. For diseases of plants and animals, certain sub-populations can drive mitigation because they are intrinsically more valuable for ecological, economic, socio-cultural or political reasons. Here we use optimal control theory to identify strategies to optimally protect a “high value” sub-population when there is a limited budget and epidemiological uncertainty. We use protection of the Redwood National Park in California in the face of the large ongoing state-wide epidemic of sudden oak death (caused by Phytophthora ramorum) as a case study. We concentrate on whether control should be focused entirely within the National Park itself, or whether treatment of the growing epidemic in the surrounding “buffer region” can instead be more profitable. We find that, depending on rates of infection and the size of the ongoing epidemic, focusing control on the high value region is often optimal. However, priority should sometimes switch from the buffer region to the high value region only as the local outbreak grows. We characterise how the timing of any switch depends on epidemiological and logistic parameters, and test robustness to systematic misspecification of these factors due to imperfect prior knowledge.


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