The distribution of fluoride in South African groundwater and the impact thereof on dental health

The most appropriate and widely used source of drinking water for the rural populations of South Africa is groundwater. Pilot studies and surveys conducted by the Department of Water Affairs and Forestry (DW AF) indicated that there are a number of boreholes across the country that contain apart from fluoride, levels of nitrate, some heavy metals, total dissolved solids, sulphates and faecal coliform (in isolated regions) that could pose a health risk if the water is used for drinking purposes. Very few boreholes have been tested for heavy metals or toxic organic substances. However considering the levels of fluoride, in general, groundwater is of acceptable quality except for some provinces in which elevated levels of natural groundwater fluoride occurs. Very high levels of fluoride, >4 mg/l occur in some groundwater sources in all nine provinces of South Africa, especially in the Limpopo, North-West, Eastern Cape, Northern Cape, Western Cape and KwaZulu Natal provinces. A superficial inspection reveals that most of the local people in those areas suffer from dental fluorosis at varying degrees. The main aim of this study is to determine the distribution of the fluoride ion concentration levels in South African groundwater and the impacts thereof on dental health. The available data is used to assess the distribution of the various fluoride ion concentration levels in some national groundwater sources. Areas of particularly high or low fluoride levels are identified. Results from an epidemiological survey carried out by the National Department of Health (NDOH) are used concurrently with the fluoride data to determine the percentage morbidity of dental fluorosis in each area The results are compared in order to determine if any relationship exists between the occurrence of fluoride in drinking water and the incidences of dental fluorosis. Vegter's lithostratigraphy and the simplified geology of South Africa are used to interpret the results and assess the role of surface geology in the release and distribution of fluorides in groundwater. The role of other factors such as climate and the interactions of the fluoride ion and other water quality parameters in aqueous media are also assessed.Dissertation (MSc (Water Utilization))--University of Pretoria, 2006.Chemical Engineeringunrestricte

Selection and prioritization of organic contaminants for monitoring in the drinking water value chain

The occurrence of organic contaminants in the drinking water value chain (from source to tap) is a growing concern for the Drinking Water industry and its consumers given the high risk these contaminants can cause to the general public. These adverse health effects include such as endocrine disruption, toxicity teratogenicity, mutagenicity and carcinogenicity. Some of these organic contaminants are included in national and international drinking water quality guidelines or standards. However, although there are similarities in the list of organic contaminants used by each organization or country, the organic contaminants are never the same given the local conditions. There are also noticeable differences in the concentration limits set as targets or criteria for organic contaminants for public health protection via the use of drinking water. A further question requiring the response from drinking water regulators was whether the standards listed in the international literature would be applicable in other countries like South Africa. Complicating this decision is the fact that the South African National Drinking Water Standard (SANS 241) does not adequately address this component of drinking water quality management. The current standard only provides for dissolved organic carbon (DOC), total trihalomethanes (TTHMs) and phenols. However, the standard contains a statement which specifies that if there is a known organic contaminant, that may pose a health threat, it should be included in the monitoring programme and evaluated against World Health Organization (WHO) guidelines. To safeguard Drinking Water industry customers, it was deemed necessary to investigate this matter and establish a tool to assist with the identification of a list of organic contaminants to be monitored in the drinking water value chain. To achieve this a specific procedure/protocol needed to be developed, hence the aim of this study which was to develop a generic protocol for the selection and prioritization of organic contaminants for monitoring in the drinking water value chain (from source to tap). To achieve this, a critical evaluation and synthesis of the available literature on the approaches for the selection and prioritization of organic variables of priority to the drinking water industry was undertaken as a first step. From the literature review it was evident that there are currently many selection and prioritization approaches which are characterized mainly by the purpose for which the exercise has been conducted for. Approaches that prioritize chemicals according to their importance as environmental contaminants have been developed by government agencies and private industries such as the Health Canada’s Canadian Environmental Protection Agency (CEPA), the United Kingdom’s Institute for Environmental Health (IEH), the European Community’s Oslo and Paris (OSPAR) convention exercise for the protection of the Northeast Atlantic marine environment and the European Union (EU)’s combined monitoring based and modelling based priority setting scheme (EU-COMMPs). A few approaches such as ones published by the United States Environmental Protection Agency (USEPA), address the needs of the Drinking Water industry and there is no generic approach to the selection, prioritization and monitoring of organic contaminants in the drinking water value chain. From the review of selection and prioritization approaches, a generic model was developed. The model consists of three main steps, the compilation of a “pool of organic contaminants, the selection of relevant parameters and criteria to screen organic contaminants and finally the application of criteria to select priority organic contaminants. It was however realized that these steps were not enough if the protocol to be develop will serve its purpose. Selection and prioritization approaches are typically intended to be fairly simple and quick methods for determining the health and environmental hazards posed by the use and release of chemical substances into different environmental systems. This was taken into account during the development of the current protocol. Understanding that a protocol is a predefined written procedural method in the design and implementation of tasks and that these protocols are written whenever it is desirable to standardize a method or procedure to ensure successful reproducibility in a similar set up, a generic protocol was developed based on the model. The protocol developed in this study, operates as a multidisciplinary contaminants management and proactive protocol, thus exchanges toxicological, water quality, agricultural, chemical and public health information. The protocol uses previous or readily available information as a point of departure. It seeks to address the challenge facing the water industry in managing the current and emerging organic contaminants that are relevant to public health protection via the use of drinking water. Once the protocol was developed, it was validated in a prototype drinking water value chain. The exercise comprised of testing each step of the protocol from the selection of the “pool of organic contaminants (Step I) to recommending the final priority list of organic contaminants (Step VII). The implementation was successfully conducted in the Rand Water drinking water value chain. Emphasis of expert judgment was made as each step was validated and the opinion of key stakeholders used to shape the process. During Step III of the protocol, an intensive literature review was conducted to determine organic contaminants that have been identified in ground and surface water systems across the world. As a result of this review, major groups of organic contaminants that have been found to occur in source water resources across the world were identified. The identified groups of organic contaminants include, pesticides, polynuclear aromatic hydrocarbons, per and polyfluoroorganic compounds, polycyclic aromatic hydrocarbons, alkanes and alkenes, C10-C13 Chloroalkanes, pharmaceuticals and personal care products [PPCPs], surfactants, benzotriazoles, cyanotoxins and Carbon-based engineered nanoparticles. The risk profile of the identified organic contaminants was established using the persistence, bio-accumulation and toxicity criteria and the development of water quality monographs as an information dissemination tool. A conceptual framework for the implementation of the protocol by water utilities and relevant institutions has been developed from the experiences learnt during the validation exercise and a priority list of organic contaminants for the monitoring in the drinking water value chain to be used by Rand Water and other water utilities was identified. Some of the organic contaminants on this are currently being analyzed for in The Rand Water’s routine organic monitoring programme. During the validation exercise, the following were noted, During the identification of the “pool of organic contaminants” from the consulted information sources such as the WHO guidelines for drinking water quality, Health Canada drinking water quality guidelines, the USEPA drinking water quality standards, the New Zealand drinking water quality standards, USEPA IRIS database, the PAN-UK list of registered pesticides for South Africa, the IARC list for recognized carcinogens and the Department of Agriculture pesticides manuals duplications were observed. The time allocated could not allow for the development of water quality monographs for all organic contaminants of concern but for a few selected contaminants whose information was inadequate to allow for decision-making. The determination of concentration levels of organic contaminants in fish, sediment and water samples could have been limited by the failure of current analytical instruments to go down to lower levels at which they occur in the drinking water value chain. Only two events could be planned, during the wet season (high flow) and dry season (low flow) based on time and budget constraints. Although various experts were consulted and invited to attend workshops in order to validate the process, the attendance could not be extended to all nine provinces given the time and budget constraints. Based on the above, recommendations were made for the dissemination and use of the products emanating from this study. For example, it is recommended that the current protocol be made available to water utilities and the process of revising the current priority list be repeated every 5 years. Further research should be conducted to obtain full coverage of organic contaminants impacting on source water quality in all ground water and surface water systems used as sources for drinking water production. Another major recommendation is the investigation of potential analytical methods that current chromatographic methods with high resolution mass spectrometry to ensure that organic contaminants can be detected at the ng/l to pg/l using a single enrichment method in order to make sure that those organic contaminants that occur at very low concentration in environmental samples can be detected. For example, the realisation that compounds such as synthetic organic polymer residues, emerging disinfectant by-products, detergent metabolites, chlorinated benzenes, alkyl phenol, polyethoxylates, their metabolites and cyanotoxins are continuously discharged into the environment via wastewater and industrial effluent discharges which increases their concentration in aquatic environment and concomitantly their potential to exert adverse health effects in water used as source for the production of drinking water necessitates that each of these groups be added to the current monitoring programme. The current water quality monographs can be used for the benefit of the Drinking Water industry. It is also recommended that a training manual on the production and use of water quality monographs is produced to facilitate their dissemination. CD-ROMs on the water quality monographs can be produced and distributed with the manual.Thesis (PhD)--University of Pretoria, 2010.School of Health Systems and Public Health (SHSPH)PhDUnrestricte

A systematic critical review of epidemiological studies on public health concerns of municipal solid waste handling

AIMS : The ultimate aim of this review was to summarise the epidemiological evidence on the association between municipal solid waste management operations and health risks to populations residing near landfills and incinerators, waste workers and recyclers. To accomplish this, the sub-aims of this review article were to (1) examine the health risks posed by municipal solid waste management activities, (2) determine the strengths and gaps of available literature on health risks from municipal waste management operations and (3) suggest possible research needs for future studies.METHODS : The article reviewed epidemiological literature on public health concerns of municipal solid waste handling published in the period 1995-2014. The PubMed and MEDLINE computerised literature searches were employed to identify the relevant papers using the keywords solid waste, waste management, health risks, recycling, landfills and incinerators. Additionally, all references of potential papers were examined to determine more articles that met the inclusion criteria. RESULTS : A total of 379 papers were identified, but after intensive screening only 72 met the inclusion criteria and were reviewed. Of these studies, 33 were on adverse health effects in communities living near waste dumpsites or incinerators, 24 on municipal solid waste workers and 15 on informal waste recyclers. Reviewed studies were unable to demonstrate a causal or non-causal relationship due to various limitations. CONCLUSION : In light of the above findings, our review concludes that overall epidemiological evidence in reviewed articles is inadequate mainly due to methodological limitations and future research needs to develop tools capable of demonstrating causal or non-causal relationships between specific waste management operations and adverse health endpoints.http://pph.sagepub.comhb2017School of Health Systems and Public Health (SHSPH

Validation of the framework for assessing occupational health risks of municipal solid waste handlers

BACKGROUND : The occupational health risks associated with municipal solid waste handling are widely documented in literature. However, no framework has been developed for their assessment. The aim of this study was to develop and validate a tool for use by local government structures. METHODS : Epidemiological evidence on human health risks associated with municipal solid waste management (MSWM) was obtained from literature and primary data collected from the study sites. An analysis of strengths, weaknesses, opportunities and threats (SWOT) of available human and environmental risk assessment frameworks was done and the findings were used as a base for the framework. The proposed framework was validated through iteration workshops in small, medium and large local government structures. Also, it was presented in a safety and health conference, in order obtain the input of occupational health and safety practitioners, researchers and policy makers. RESULTS : A draft framework was produced, validated and revised to incorporate resolutions made from the iteration workshops. The final framework constitutes four inputs, six phases and four principles. Each phase has defined outputs. CONCLUSION : The applicability of the framework to situations of resource-constrained economies has been tested through validation workshops in small, medium and large local government structures of a low income country. In light of the multi-methods used in developing the framework and the input of practitioners in validation workshops, the framework appears relevant for the purposes of assessing occupational health risks of municipal solid waste handlers (MSWHs).http://www.ccsenet.org/journal/index.php/gjhs/indexam2019School of Health Systems and Public Health (SHSPH

Association between exposure to drinking water disinfection byproducts and adverse pregnancy outcomes in South Africa

Currently, there is contradictory evidence for the risk of adverse pregnancy outcomes associated with maternal exposure to disinfection byproducts (DBPs). We examine the association between maternal exposure to trihalomethanes (THMs) in drinking water and adverse pregnancy outcomes, including premature birth, low birth weight (LBW) and small for gestational age (SGA). In total, 1,167 women older than 18 years were enrolled at public antenatal venues in two geographical districts. For each district, we measured the levels of residential drinking water DBPs (measured in THMs) through regulatory data and routine water sampling. We estimated the individual uptake of water of each woman by combining individual water use and uptake factors. Increased daily internal dose of total THMs during the third trimester of pregnancy significantly increased the risk of delivering premature infants (AOR 3.13, 95% CI 1.36–7.17). The risk of premature birth was also positiviely associated with exposure to total THMs during the whole pregnancy (AOR 2.89, 95% CI 1.25–6.68). The risk of delivering an SGA and LBW infant was not associated with maternal exposure to THMs. Our findings suggest that exposure to THMs is associated with certain negative pregnancy outcomes. The levels of THMs in water should be routinely monitored.This work was supported by the South African National Research Foundation (NRF) (Grant number SFH150625121049).http://www.iwaponline.com/jwh/default.htmam2022School of Health Systems and Public Health (SHSPH

Drivers and barriers to sustained use of Blair ventilated improved pit latrine after nearly four decades in rural Zimbabwe

BACKGROUND : Some latrines remain unused even under conditions of high coverage in rural areas of low-and middle-income countries. Not much is known on household latrine use in the long term in the absence of an intervention. The current work assesses drivers and barriers to sustained use of a ventilated improved pit latrine (Blair VIP) design where it originated and how rural households adapt it to climate change. METHODS : A mixed methods study was conducted from November 2020 to May 2021 among rural households of Mbire district, Zimbabwe. A cross sectional survey of 238 households with Blair ventilated improved pit (BVIP) latrines was conducted using a questionnaire and a latrine observation checklist. Data were analysed using logistic regression. Qualitative data were collected using six focus groups among house heads and analysed by thematic analysis. RESULT : The latrine has perceived health, non-health and hygiene benefits for its sustained use. However, there are design, environmental and social barriers. The quantitative study indicated that determinants of latrine use were contextual (individual and household levels) and technology (individual level) factors. Focus groups indicated that latrine use was influenced by social, technology and contextual factors at multiple level factors. Interplay of factors influenced the intention to adapt the BVIP latrine to climate change. Local climate change adaptation strategies for the latrine were odour and erosion control, construction of the conventional latrine design and raised structures. CONCLUSION : The conventional BVIP latrine design is durable and relatively resilient to climate change with high local household use. High construction cost of the latrine causes households to build incomplete and poor quality designs which affect odour and fly control. These are barriers to sustained latrine use. The government should implement the new sanitation policy which considers alternative sanitation options and offer community support for adapting sanitation to climate change.SUPPORTING INFORMATION : S1 Fig. Modified steps of the focus group discussion technique with permission [43]. https://doi.org/10.1371/journal.pone.0265077.s001S1 Table. Integrated behavioural model for water, sanitation and hygiene [30]. https://doi.org/10.1371/journal.pone.0265077.s002S1 File. Latrine use household questionnaire. https://doi.org/10.1371/journal.pone.0265077.s003S2 File. Informed consent document. https://doi.org/10.1371/journal.pone.0265077.s004S3 File. Blair ventilated improved pit latrine construction checklist. https://doi.org/10.1371/journal.pone.0265077.s005S4 File. Focus group discussion guide. https://doi.org/10.1371/journal.pone.0265077.s006S5 File. Phases of thematic analysis [46]. https://doi.org/10.1371/journal.pone.0265077.s007http://www.plosone.orgdm2022School of Health Systems and Public Health (SHSPH

Adapting sanitation needs to a latrine design (and its upgradable models) : a mixed method study under lower middle-income rural settings

Rural households have latrine preferences and unique sanitation needs. An assessment of how rural households adapt their sanitation needs to a nationally encouraged latrine design was done. A cross-sectional survey was conducted among 790 households in a rural district of Zimbabwe from November 2020 to May 2021. Data were analysed using logistic regression. Qualitative data were collected using focus groups and analysed using thematic analysis. Analyses were done in STATA 16 and considered significant at p < 0.05. There was low adoption of the Blair ventilated improved pit latrine and its upgradable models. Significant predictor variables of BVIP latrine adoption were mainly contextual and psychosocial at the individual and household levels. They included source and level of household income, residence period, nature of homestead, number of cattle owned, knowledge of sanitation options and perceived high latrine cost. The latrine design was considered not a pro-poor option as it was unaffordable by many rural households resulting in its non-completion, poor-quality designs, alternative options, sharing and open defaecation. Poverty appears the main barrier for latrine ownership. However, a window of opportunity to improve access to sanitation in rural Zimbabwe exists by considering alternative sanitation options and financial investment mechanisms.Supplementary File 1. Multistage sampling of households for Mbire district survey, northern Zimbabwe, 2021.Supplementary File 2. Summary of selected households for Mbire district survey, Zimbabwe, 2021.Supplementary File 3. Questionnaire for Mbire district, Zimbabwe Questionnaire ID.Supplementary File 4. Focus group guide.Supplementary File 5. The integrated behavioural model for water, sanitation, and hygiene (IBM-WASH).Supplementary File 6. Informed consent form.Supplementary File 7. Characteristics of participants in focus group discussions, Mbire district, northern Zimbabwe, 2021 (n = 39).https://www.mdpi.com/journal/sustainabilitydm2022School of Health Systems and Public Health (SHSPH

Drinking water disinfection by-products exposure and health effects on pregnancy outcomes : a systematic review

Epidemiological studies have found that maternal exposure to disinfection by-products (DBPs) may lead to adverse pregnancy outcomes although the findings tend to be inconsistent. The objective of this study was to systematically review the evidence in association to drinking water DBP exposure in relation to adverse pregnancy outcomes. Peer-reviewed articles were identified using electronic databases searched for studies published in English language. Studies selected for review were evaluated for exposure assessment, confounders, and analyses risks of bias in the selection, outcomes assessment, and attrition. A comprehensive search and screening yielded a total of 32 studies, of which 12 (38%) reported a statistical association between maternal exposure to DBPs and adverse pregnancy outcomes. A maternal exposure to trihalomethanes shows an increased risk of small for gestational age (SGA) and slightly increased risk of pregnancy loss. Risks of bias were low among the studies included in the review. Evidence on association relating to adverse pregnancy outcomes to DBP exposure is still less significant. There is a need for future robust research on this field, with the use of urinary TCCA biomarkers as a direct exposure assessment method for this field.The South African National Research Foundation (NRF) Grant (SFH150625121049).http://jwh.iwaponline.com2019-08-19hj2018School of Health Systems and Public Health (SHSPH

Maternal urinary levels of trichloroacetic acid and association with adverse pregnancy outcomes

The current study aimed to determine the association between trichloroacetic acid (TCAA) levels and adverse pregnancy outcomes among third-trimester pregnant women who were exposed to chlorinated drinking water. A total of 205 pregnant women who participated in the disinfection by-products exposure and adverse pregnancy outcome study in South Africa were randomly asked to participate in this study by providing their morning urine sample voids. Samples were analysed for urinary creatinine and TCAA. Furthermore, participants gave individual data using a structured questionnaire. The mean (median) concentration of creatinine-adjusted urinary TCAA was 2.34 (1.95) μg/g creatinine. Elevated levels of creatinine-adjusted TCAA concentrations showed an increased risk of premature birth, small for gestational age (SGA) and low birth weight. There was no significant statistical correlation observed between creatinine-adjusted TCAA concentrations and the total volume of cold water ingested among the study population. No statistically significant association was observed between creatinine-adjusted urinary TCAA and premature birth, SGA and low birth weight newborns among the study subjects. However, the urinary TCAA concentrations identified in this study suggest potential health risks towards women and foetus. Therefore, further studies are warranted to prevent further adverse pregnancy outcomes.The South African NRF Grant (SFH150625121049)http://jwh.iwaponline.comhj2020School of Health Systems and Public Health (SHSPH

Effect of sanitation interventions on health outcomes : a systematic review of cluster-randomized controlled trials in rural communities of low- and middle-income countries

A systematic review of published literature (2000–2019) evaluating the impact of sanitation interventions on the prevalence of disease, parasite infestation, and/or child growth using randomized controlled trials (RCTs) was done according to the PRISMA checklist. Earlier reviews indicated mixed evidence citing relatively poor quality evidence from mixed designs. Public health policy and practice appear to rely on evidence from RCTs. Records were searched in six electronic databases. The methodological quality of RCTs was assessed using the Cochrane collaboration risk of bias tool. Fifteen records (2.0%) were included for review. Impact trials were done in rural communities of African and Asian countries. The significant effect of sanitation-focus interventions was found in one trial for the prevalence of childhood diarrhea (14.3%), three trials for parasite infestation (37.5%), and two trials (25.0%) for child growth. Results indicate mixed quality evidence from RCT designs. Evidence is limited and suggestive of the impact of sanitation on parasite infestation and child growth. Further rigorous sanitation intervention trials under varying settings are needed to show what really works and under what settings. Future work may explore sanitation behavior change strategies and latrine options to address the challenges of poor latrine use under high sanitation coverage.Table S1: Assessment of risk of bias for 15 RCTs used to determine the impact of sanitation on health outcomes (Adapted from The Cochrane Collaboration’s tool for assessing risk of bias).https://www.mdpi.com/journal/ijerpham2022School of Health Systems and Public Health (SHSPH