65 research outputs found

    Effects of diffuse effluents from Botshabelo on the microbiological quality of water in the Modder River

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    ThesisThe value of selected indicator micro-organisms for assessment of faecal pollution of water, as well as the distinction of faecal pollution of animal or human origin of pollution, has been investigated. The following indicators were included: faecal coliform bacteria, faecal streptococci, sorbitol-fermenting bifidobacteria, Rhodococcus coprophilus, somatic and male-specific coliphages and phages of Bacteroides tragilis. Comparative tests were carried out on water samples collected from a stream and river, and their respective catchments, exposed to predominantly faecal pollution of domestic animal origin. The same stream and river with catchments, were sampled after downstream exposure to run-off from a low socioeconomic developing settlement with restricted sanitation. Samples were collected from perennial flow in the stream and river during the dry season and from storm water run-off during general rain and immediately after thunder storms. Storm water run-off reached faecal coliform counts of up to 4 400 000 per . 100 ml, which is equivalent to that of many sewage effluents. Faecal pollution of the aquatic environment was less during the dry season. Sorbitol-fermenting bifidobacteria were identifiable with faecal pollution of human origin, and R coprophi/us with that of animal origin. Male specific coliphages were identifiable with sewage pollution as well as general faecal pollution of water. Certain selected ratios for the indicator organisms indicated possible distinction between faecal pollution of human origin and faecal pollution predominantly of animal origin under certain circumstances. Phages of B tragi/is were not detected in any of the samples, which implies that their application in this situation would require more sensitive techniques. The results show that the run-off from the developing settlement constituted a major source of pollution for a river catchment which downstream is used as a source of water for human consumption and that faecal pollution of human and animal origin can reliably be distinguished by means of combinations of appropriate indicators

    A framework for assessing and predicting the environmental health impact of infectious diseases: a case study of leptospirosis

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    This article demonstrates the practical application of an integrated environmental health impact assessment (IEHIA) methodology to investigate an infectious disease (leptospirosis) and the value of using such an approach to estimate future health impact. The assessment described the current health impact (using leptospirosis seroprevalence as a proxy measure) and estimated the future health impact based on scenarios that included indicators of different risk factors. The application of an IEHIA methodology to assess the health impact of an infectious disease was shown to enhance the ability to quantify associations between a disease agent and its health impact by taking into account the environmental drivers of transmission, human behaviour, socioeconomic factors, and the multiple pathways through which exposure and infection could occur

    An investigation of the use of rectangular insecticide-treated nets for malaria control in Chipinge District, Zimbabwe: a descriptive study

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    In 2007, Zimbabwe government distributed rectangular insecticide treated nets in Chipinge District, covering 100% of population at risk. However, malaria morbidity continued increasing from 492/1000 (49.2%) in 2007 to 667/1000 (66.7%) in 2008. A study was conducted in Chipinge District in May 2009 to investigate the use of rectangular insecticide treated nets and factors affecting their use in malaria prevention. A descriptive cross-sectional study was conducted. Quantitative and qualitative methods were triangulated to assess utilisation of rectangular insecticide treated nets. Five interviewers administered 380 questionnaires to senior matriarchs selected from five wards, with 19,667 sampling frame (19,667/380 = 52). Five focus group discussions were conducted. Quantitative data were analysed using Statistical Package for the Social Sciences, while qualitative data were summarised into thematic areas. Approximately, 95% of respondents knew that malaria was caused by mosquito bites. Perception of nets as malaria preventative measure was high (88%). Utilization of rectangular insecticide treated nets was low (33%) with 81% of those not using them expressed difficulty procedures of mounting them and unavailability of related accessories as main reasons. People preferred conical insecticide treated nets (84%) compared to rectangular insecticide treated nets (15%). Although the Chipinge people accepted insecticide treated nets for malaria prevention, procedure of mounting rectangular insecticide treated nets and accessing related accessories prevented consistent use.In order for insecticide treated net project to have impact on malaria prevention, priority should be given to conical shape or rectangular shape with adequate accessories like wire nails and strings or twine

    Assessing exposure of young children to common endocrine-disrupting chemicals in the home environment: A review and commentary of the questionnaire-based approach

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    Background: Although infants and young children are particularly vulnerable to endocrine disrupting chemical (EDC) exposure, there is an absence of comprehensive exposure data for this age group. As young children spend the majority of their time indoors, improved methods of exposure assessment are needed to characterise the health risks from exposures in the home environment. Biologic assessment, which has been considered the gold standard for exposure assessment in recent years, is difficult to conduct in young children. Questionnaires are an alternative and indirect method of predicting exposure, which may overcome some of the limitations of direct exposure assessment. Research problem: The feasibility of using a questionnaire-based approach to predict exposure of young children to EDCs in the home has yet to be comprehensively reviewed. Moreover, there is no one questionnaire that has been validated for predicting the exposure of infants to common EDCs in the home. Aims and objectives: The aim of this review is to discuss the use and validation of the questionnaire-based approach to predict exposure of children to chemicals from three common classes of EDCs in the home, namely, plasticisers, flame retardants, and insecticides. We discuss the strengths and weaknesses of the questionnaire-based approach as well as the important pathways of exposure in the home environment, by which to guide the design and validation of future exposure questionnaires. Results: The findings from our review indicate that the questionnaire-based approach is a valuable tool in the prediction of exposure to persistent organic pollutants, as well as to toxicants that have consistent patterns of exposure. With improvements to the design and validation process, the questionnaire-based approach may also prove to be a reliable instrument in predicting exposure to EDCs with short-half lives, including bisphenol A, phthalates, and pyrethroid and organophosphate insecticides

    Environmental health impacts of unconventional natural gas development: a review of the current strength of evidence

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    Rapid global expansion of unconventional natural gas development (UNGD) raises environmental health concerns. Many studies present information on these concerns, yet the strength of epidemiological evidence remains tenuous. This paper is a review of the strength of evidence in scientific reporting of environmental hazards from UNGD activities associated with adverse human health outcomes. Studies were drawn from peer-reviewed and grey literature following a systematic search. Five databases were searched for studies published from January 1995 through March 2014 using key search terms relevant to environmental health. Studies were screened, ranked and then reviewed according to the strength of the evidence presented on adverse environmental health outcomes associated with UNGD. The initial searches yielded >1000 studies, but this was reduced to 109 relevant studies after the ranking process. Only seven studies were considered highly relevant based on strength of evidence. Articles spanned several relevant topics, but most focussed on impacts on typical environmental media, such as water and air, with much of the health impacts inferred rather than evidenced. Additionally, the majority of studies focussed on short-term, rather than long-term, health impacts, which is expected considering the timeframe of UNGD; therefore, very few studies examined health outcomes with longer latencies such as cancer or developmental outcomes. Current scientific evidence for UNGD that demonstrates associations between adverse health outcomes directly with environmental health hazards resulting from UNGD activities generally lacks methodological rigour. Importantly, however, there is also no evidence to rule out such health impacts. While the current evidence in the scientific research reporting leaves questions unanswered about the actual environmental health impacts, public health concerns remain intense. This is a clear gap in the scientific knowledge that requires urgent attention

    All-age hospitalization rates in coal seam gas areas in Queensland, Australia, 1995–2011

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    Background: Unconventional natural gas development (UNGD) is expanding globally, with Australia expanding development in the form of coal seam gas (CSG). Residents and other interest groups have voiced concerns about the potential environmental and health impacts related to CSG. This paper compares objective health outcomes from three study areas in Queensland, Australia to examine potential environmentally-related health impacts. Methods: Three study areas were selected in an ecologic study design: A CSG area, a coal mining area, and a rural/agricultural area. Admitted patient data, as well as population data and additional factors, were obtained for each calendar year from 1995 through 2011 to calculate all-age hospitalization rates and age-standardized rates in each of these areas. The three areas were compared using negative binomial regression analyses (unadjusted and adjusted models) to examine increases over time of hospitalization rates grouped by primary diagnosis (19 ICD chapters), with rate ratios serving to compare the within-area regression slopes between the areas. Results: The CSG area did not have significant increases in all-cause hospitalization rates over time for all-ages compared to the coal and rural study areas in adjusted models (RR: 1.02, 95 % CI: 1.00-1.04 as compared to the coal mining area; RR: 1.01, 95 % CI: 0.99-1.04 as compared to the rural area). While the CSG area did not show significant increases in specific hospitalization rates compared to both the coal mining and rural areas for any ICD chapters in the adjusted models, the CSG area showed increases in hospitalization rates compared only to the rural area for neoplasms (RR: 1.09, 95 % CI: 1.02-1.16) and blood/immune diseases (RR: 1.14, 95 % CI: 1.02-1.27). Conclusions: This exploratory study of all-age hospitalization rates for three study areas in Queensland suggests that certain hospital admissions rates increased more quickly in the CSG study area than in other study areas, particularly the rural area, after adjusting for key sociodemographic factors. These findings are an important first step in identifying potential health impacts of CSG in the Australian context and serve to generate hypotheses for future studies

    Development of a questionnaire-based insecticide exposure assessment method and comparison with urinary insecticide biomarkers in young Australian children

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    Environmental and behavioural factors assessed via an online questionnaire were compared to insecticide metabolite concentrations in urine collected from 61 children from South East Queensland, Australia. Metabolite concentrations (μg/L urine) were transformed using the natural logarithm prior to regression analysis and adjusted for age and creatinine. A significant dietary association was reported for vegetable intake and 3-phenoxybenzoic acid (3-PBA) (β: 1.47 for top quartile of intake versus bottom quartile of intake 95% CI: 0.36, 2.57). Intake of vegetables and fruit were also positively associated with sum non-specific organophosphate metabolites (ƩnsOP). ƩnsOP concentrations were lower when fruits and vegetables were always or almost always washed prior to cooking or eating (β: -0.69 95% CI: -1.25, -0.12). In multivariable modelling 3-PBA concentrations were also associated with hand-washing frequency (β: 1.69 95% CI: 0.76, 2.61 for  3 day), presence of a dog in the home (β: 0.73 95% CI: 0.07, 1.38), frequency of pest-spray use in the summer months (β: 0.88 95% CI: 0.22, 1.54 weekly versus less than weekly) and season (β: 0.88 95% CI: 0.32, 1.44 for spring/summer versus winter/autumn). This is the first study in Australia to report dietary, behavioural and environmental factors associated with biomarkers of insecticide exposure in young children

    The association of water carriage, water supply and sanitation usage with maternal and child health. A combined analysis of 49 Multiple Indicator Cluster Surveys from 41 countries

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    Background  Millions of people carry water home from off-plot sources each day and lack improved sanitation. Research on the health outcomes associated with water fetching is limited, and with usage of improved sanitation is inconclusive.  Objectives  To analyse the association of water fetching, unimproved water supplies, and usage of improved sanitation facilities with indicators of women’s and children’s health.  Methods  49 Multiple Indicator Cluster Surveys from 41 countries were merged, creating a data set of 2,740,855 people from 539,915 households. Multilevel, multivariable analyses were conducted, using logistic regression for binary outcomes, negative binomial regression for count data and ordinary linear regression for linear data. We adjusted for confounding factors and accounted for clustering at survey, cluster and household level.  Results  Compared to households in which no-one collects water, water fetching by any household member is associated with reduced odds of a woman giving birth in a health care facility (OR 0.88 to 0.90). Adults collecting water is associated with increased relative risk of childhood death (RR 1.04 to 1.05), children collecting water is associated with increased odds of diarrheal disease (OR 1.10 to 1.13) and women or girls collecting water is associated with reduced uptake of antenatal care (β-0.04 to -0.06) and increased odds of leaving a child under five alone for one or more hours, one or more days per week (OR 1.07 to 1.16). Unimproved water supply is associated with childhood diarhhoea (OR 1.05), but not child deaths, or growth scores. When the percentage of people using improved sanitation is more than 80% an association with reduced childhood death and stunting was observed, and when more than 60%, usage of improved sanitation was associated with reduction of diarhhoea and acute undernutrition.  Conclusion  Fetching water is associated with poorer maternal and child health outcomes, depending on who collects water. The percentage of people using improved sanitation seems to be more important than type of toilet facility, and must be high to observe an association with reduced child deaths and diarhhoea. Water access on premises, and near universal usage of improved sanitation, is associated with improvements to maternal and child health
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