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ABSTRACTConcentrations OF Chloride, nitrate‐N, sulphate, sodium, ammoniacal‐N and potassium were monitored for six days in 20 riverine sediment‐water flow tank experiments. Only nitrate‐N and ammonical‐N showed consistent patterns over a period of time. Nitrate‐removal rates ranged from −15 mg N/m2.d (coarse material) to +49 mg N/m2.d (fine sediment) when the initial concentration of nitrate‐N was 2 mg/1. An increase in initial concentration to 11 mg/1 produced corresponding removal rates of 67–241 mg N/m2.d. Likely removal mechanisms are discussed. The results suggest management possibilities for stream bed ecosystems and raw water impoundments with respect to nitrogen cycling.

AbstractThis paper provides a detailed assessment of the microbiological quality of a selection of private water supplies. Samples were taken from 91 supplies and analyzed for total coliforms, faecal coliforms and faecal streptococci. The microbiological quality of the samples was generally poor, with almost 50% of the supplies failing to meet the required standards on at least one occasion. Given the high level of sanitary microbiological failures, there is the possibility that harmful microorganisms could be present and a significant risk to health cannot be discounted.

AbstractThis paper provides a detailed assessment of the microbiological quality of a selection of private water supplies. Samples were taken from 91 supplies and analyzed for total coliforms, faecal coliforms and faecal streptococci. The microbiological quality of the samples was generally poor, with almost 50% of the supplies failing to meet the required standards on at least one occasion. Given the high level of sanitary microbiological failures, there is the possibility that harmful microorganisms could be present and a significant risk to health cannot be discounted.

Covers fifty-five national historic landmarks, including battlefields, forts, lighthouses, and rocket sites, that illustrate how American defenders took part in various military actions throughout history. ; Covers fifty-five national historic landmarks, including battlefields, forts, lighthouses, and rocket sites, that illustrate how American defenders took part in various military actions throughout history. ; Mode of access: Internet.

ABSTRACTData for 425 sampling locations in England and Wales, covering the 1987 bathing season, were analysed against a range of six water‐quality standards used by European and North American agencies. The following order of relative stringency was established: EEC guide level > US Environmental Protection Agency† > Toronto†> Canadian Federal† > Modified EEC standard > EEC imperative level†.All European Community (EC) countries, at present abiding by the'imperative'bacteriological standards of the bathing waters Directive, would experience a significant increase in non‐compliance for the faecal coliform parameter if standards were altered from the current EEC imperative criteria to any of the existing alternative beach management standards.

AbstractA pilot study was conducted to investigate the feasibility of using adult volunteers to examine the possible health effects of bathing in UK seawaters which passed the EC bathing waters Directive. Langland Bay, near Swansea, was chosen for this experiment, which was conducted on 2 September 1989. Adult volunteers were recruited from the City of Swansea and randomly divided into bather and non‐bather groups. All volunteers were given medical examinations and medical questionnaire interviews before and after 2 September.Water quality on the day of the test was relatively unpolluted, as indexed by the commonly‐employed bacterial and viral indicator species. The detailed medical questionnaire resulted in higher reported attack rates of perceived illness in both bather and non‐bather groups than those published in previous studies, which have commonly employed a single telephone interview to acquire disease perception data. Statistically‐significant differences in the bather and non‐bather cohorts were found for the following perceived symptoms: sore throat, ear symptom, eye symptom at 3 d after 2 September, and for diarrhoea at three weeks after the experiment. The clinical tests employed failed to confirm these significant perceived symptom attack rate differentials.The significance of these results is discussed in the context of previous research protocols to demonstrate the feasibility of this novel prospective controlled cohort approach for the acquisition of scientifically robust data on the health effect of recreational water use. If taken to a full‐scale study, it is argued that this research protocol could offer considerable advantages over past methods and lead to scientifically valid water‐quality standards for recreational waters.

ABSTRACTThe discharge of sewage to the unique UK coastal environment has been a traditional and cost‐effective means of treatment for many decades. This disposal option is increasingly questioned by professionals with public‐health responsibilities as well as by environmental pressure groups. There are limited firm data on the epidemiological significance of existing disposal practices: the established prospective methods, developed by North American workers in this area, have not provided a scientifically‐robust, epidemiological, research protocol. This leaves a scientific vacuum for those with operational and policy responsibilities in this important and sensitive area of water resource management.

ABSTRACTThe introduction of ultraviolet disinfection in Jersey has achieved significant improvements in water quality. However, bathing waters in St Aubin's Bay and shellfish flesh have failed to comply with microbial standards. Streams and seepages from coastal structures were investigated as potential indicator organism sources (total and faecal coliforms, faecal streptococci). Seepages were an unimportant bacterial source as concentrations were low. Geometric mean concentrations in streams were up to four orders of magnitude higher than in final sewage‐treatment works effluent, and concentrations increased significantly at high stream discharge. Rainfall‐induced pulses of poor water quality occurred two to three times per week during the 1993 summer season. Natural discharges from island catchments thus contribute significantly to the bacterial load received at the coast, especially during high flow events. These observations have implications for other UK and European schemes using tertiary disinfection technology to attain water quality targets in coastal waters.

ABSTRACTFour studies were carried out at separate locations to investigate the relationship between health effects and low‐contact water sports, and intensive microbiological sampling was conducted in parallel to the health studies at each site. The two sports examined were marathon canoeing and rowing.The extremes of water quality were at the estuarine sites on the River Torridge, where pollution levels varied from a geometric mean faecal coliform value of 62/100 ml at the Appledore/Instow site to 4613/100 ml at the Bideford site.A comparison of 'exposed' and 'unexposed' groups, 5–7 days after exposure, showed that the health effects of low‐contact water sports are minimal, within the water quality ranges which were studied.

AbstractThis paper explores the application of a catchment faecal‐indicator budget approach to the examination of faecal‐indicator sources impacting on coastal recreational water quality. This involves (i) the characterization of water quality in sewage effluent and riverine inputs, and (ii) measurement and estimation of input flows; the product of these components yields the input flux of indicator organisms from each source. The impact of sewage‐treatment scenarios on budgets is also investigated.

The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above. ; BACKGROUND: Asthma is a disease characterised by ventilation heterogeneity (VH). A number of studies have demonstrated that VH markers derived using impulse oscillometry (IOS) or multiple breath washout (MBW) are associated with key asthma patient related outcome measures and airways hyper responsiveness. However the topographical mechanisms of VH in the lung remain poorly understood. OBJECTIVES: We hypothesised that specific regionalisation of topographical small airway disease would best account for IOS and MBW measured indices in patients. METHODS: We evaluated paired expiratory/inspiratory computed tomography in a cohort of asthmatic (n=41) and healthy volunteers (n=11) to understand the determinants of clinical VH indices commonly reported using IOS and MBW. Parametric response mapping (PRM) was utilised to calculate functional small airways disease marker PRMfSAD and Hounsfield unit (HU) based density change from total lung capacity to functional residual capacity (ΔHU); gradients of ΔHU, in gravitationally perpendicular (parallel), inferior-superior (anterior-posterior) axes, were quantified. RESULTS: ΔHU gradient in the inferior-superior axis provided the highest level of discrimination of both Sacin and R5-20. Patients with a high inferior-superior ΔHU gradient demonstrated evidence of reduced specific ventilation in the lower lobes of the lungs and high levels of PRMfSAD. A computational small airway tree model confirmed that constriction of gravitationally dependant lower zone small airway branches would promote the largest increases in R5-R20. Ventilation gradients correlated with asthma control and quality of life but not with exacerbation frequency. CONCLUSIONS: Lower lobe predominant small airways disease is a major driver of clinically measured VH in adult asthma. ; Supported by the Sir Jules Thorn trust, "Systems medicine: novel mathematical approaches to personalized care in asthma patients," through a clinical senior lecturer award (Professor Siddiqui). Additional funding was received for the original computed tomographic scan and physiologic analyses from Roche Pharmaceuticals (C.B. and S.S.) and the European Union Airways Disease Predicting Outcomes in Patient Specific Computational Models (AirPROM-FP7) consortium. This article was also supported by the National Institute for Health Research (NIHR) Leicester Respiratory Biomedical Research Centre (BRC). ; Peer-reviewed ; Post-print