Relations between personal exposure to elevated concentrations of arsenic in water and soil and blood arsenic levels amongst people living in rural areas in Limpopo, South Africa

DATA AVAILABILITY : The datasets generated during this study are available from the authors upon request.CHANGE HISTORY : 30 January 2024. A Correction to this paper has been published: https://doi.org/10.1007/s11356-024-32103-9Exposure to arsenic even at low levels can lead to adverse health outcomes, however, there is a paucity of research from South Africa in relation to human exposure to arsenic. We investigated long-term exposure of residents in Limpopo province, South Africa, in a cross-sectional study by analysing water, soil and blood arsenic concentrations from two arsenic-exposed (high and medium–low exposure) villages and one non-exposed (control) village. There were statistically significant differences in the distribution of arsenic in water, soil and blood amongst the three sites. The median drinking water arsenic concentration in the high-exposure village was 1.75 µg/L (range = 0.02 to 81.30 µg/L), 0.45 µg/L (range = 0.100 to 6.00 µg/L) in the medium- / low-exposure village and 0.15 µg/L (range =  < limit of detection (LOD) to 29.30 µg/L) in the control site. The median soil arsenic concentration in the high-exposure village was 23.91 mg/kg (range =  < LOD to 92.10 mg/kg) whilst arsenic concentrations were below the limit of detection in all soil samples collected from the medium-/low-exposure and control villages. In the high-exposure village, the median blood arsenic concentration was 1.6 µg/L (range = 0.7 to 4.2 µg/L); 0.90 µg/L (range =  < LOD to 2.5 µg/L) in the medium-/low-exposure village and 0.6 µg/L (range =  < LOD to 3.3 µg/L) in the control village. Significant percentages of drinking water, soil and blood samples from the exposed sites were above the internationally recommended guidelines (namely, 10 µg/L, 20 mg/kg and 1 µg/L, respectively). Majority of participants (86%) relied on borehole water for drinking and there was a significant positive correlation between arsenic in blood and borehole water (p-value = 0.031). There was also a statistically significant correlation between arsenic concentrations in participants’ blood and soil samples collected from gardens (p-value = 0.051). Univariate quantile regression found that blood arsenic concentrations increased by 0.034 µg/L (95% CI = 0.02–0.05) for each one unit increase in water arsenic concentrations (p < 0.001). After adjusting for age, water source and homegrown vegetable consumption in multivariate quantile regression, participants from the high-exposure site had significantly higher blood concentrations than those in the control site (coefficient: 1.00; 95% CI = 0.25–1.74; p-value = 0.009) demonstrating that blood arsenic is a good biomarker of arsenic exposure. Our findings also provide new evidence for South Africa on the association between drinking water and arsenic exposure, emphasising the need for the provision of potable water for human consumption in areas with high environmental arsenic concentrations.Open access funding provided by South African Medical Research Council. All authors receive research funding from the SAMRC.https://www.springer.com/journal/11356hj2024Geography, Geoinformatics and MeteorologySDG-06:Clean water and sanitationSDG-11:Sustainable cities and communitie

Exploring Meteorological Conditions and Human Health Impacts during Two Dust Storm Events in Northern Cape Province, South Africa: Findings and Lessons Learnt

Dust storms are meteorological hazards associated with several adverse health impacts including eye irritations, respiratory and cardiovascular disorders, and vehicular road accidents due to poor visibility. This study investigated relations between admissions from a large, public hospital that serves people living in Northern Cape and Free State provinces, South Africa during 2011 to 2017, and meteorological variables (temperature and air quality) during two dust storms, one in October 2014 (spring) and the second in January 2016 (summer), identified from the media as no repository of such events exists for South Africa. Distributed nonlinear lag analysis and wavelet transform analysis were applied to explore the relationships between hospital admissions for respiratory and cardiovascular diseases, eye irritation, and motor vehicle accidents; maximum temperature, and two air quality ‘proxy measures,’ aerosol optical depth and Ångström exponent, were used as ground-based air quality data were unavailable. Eye irritation was the most common dust-related hospital admission after both dust storm events. No statistically significant changes in admissions of interest occurred at the time of the two dust storm events, using either of the statistical methods. Several lessons were learnt. For this type of study, ground-based air quality and local wind data are required; alternative statistical methods of analysis should be considered; and a central dust storm repository would help analyze more than two events. Future studies in South Africa are needed to develop a baseline for comparison of future dust storm events and their impacts on human health

Applying a WASH risk assessment tool in a rural South African setting to identify risks and opportunities for climate resilient communities

Climate change threatens the health and well-being of populations. We conducted a risk assessment of two climate-related variables (i.e., temperature and rainfall) and associated water, sanitation and hygiene (WASH)-related exposures and vulnerabilities for people living in Mopani District, Limpopo province, South Africa. Primary and secondary data were applied in a qualitative and quantitative assessment to generate classifications of risk (i.e., low, medium, or high) for components of hazard/threat, human exposure, and human vulnerability. Climate-related threats were likely to impact human health due to the relatively high risk of waterborne diseases and WASH-associated pathogens. Vulnerabilities that increased the susceptibility of the population to these adverse outcomes included environmental, human, physical infrastructure, and political and institutional elements. People of low socio-economic status were found to be least likely to cope with changes in these hazards. By identifying and assessing the risk to sanitation services and water supply, evidence exists to inform actions of government and WASH sector partners. This evidence should also be used to guide disaster risk reduction, and climate change and human health adaptation planning.DATA AVAILABILITY STATEMENT : The laboratory sample data are available from the National Health Laboratory Services. All hazard-related data were extracted from publicly available manuscripts as cited in the text.The South African Medical Research Council and the National Research Foundation. The A.P.C. was funded by the South African Medical Research Council.https://www.mdpi.com/journal/ijerphGeography, Geoinformatics and Meteorolog

Sun protection to improve vaccine effectiveness in children in a high ambient ultraviolet radiation and rural environment: an intervention study

BACKGROUND: Vaccination is a mainstay of preventive healthcare, reducing the incidence of serious childhood infections. Ecological studies have demonstrated an inverse association between markers of high ambient ultraviolet (UV) radiation exposure (e.g., sunny season, low latitude of residence) and reduction in the vaccination-associated immune response. Higher sun exposure on the day prior to and spanning the day of vaccination has been associated with a reduced antigen-specific immune response independent of skin pigmentation. The South African Department of Health's Expanded Programme on Immunisation provides free vaccinations in government primary health care clinics. In some areas, these clinics may have only a small waiting room and patients wait outside in full sun conditions. In rural areas, patients may walk several kilometres to and from the clinic. We hypothesised that providing sun protection advice and equipment to mothers of children (from 18 months) who were waiting to be vaccinated would result in a more robust immune response for those vaccinated. METHODS: We conducted an intervention study among 100 children receiving the booster measles vaccination. We randomised clinics to receive (or not) sun protection advice and equipment. At each clinic we recorded basic demographic data on the child and mother/carer participants, their sun exposure patterns, and the acceptability and uptake of the provided sun protection. At 3-4 weeks post-vaccination, we measured measles IgG levels in all children. DISCUSSION: This is the first intervention study to assess the effect of sun protection measures on vaccine effectiveness in a rural, real-world setting. The novel design and rural setting of the study can contribute much needed evidence to better understand sun exposure and protection, as well as factors determining vaccine effectiveness in rural Africa, and inform the design of immunisation programmes. (TRN PACTCR201611001881114, 24 November 2016, retrospective registration).This study received funding through a peer reviewed process from the National Research Foundation (NRF) of South Africa (Grant number: 93426). Funding was awarded to CW as a Y-rated researcher funding grant. Furthermore, funding from the South African Medical Research Council (SAMRC), as part of a Heat and Health Flagship 3-year project funded by SAMRC seed funding, was provided to co-fund the research nurses employed in the study. These additional funds were needed given the low rates of vaccination noted in the clinics during the pre-study site visits and the need for longer periods of work by the research nurses (i.e., additional study months)

Exploring the association between ambient temperature and daily hospital admissions for diarrhea in Mopani district, Limpopo province, South Africa

DATA AVAILABILITY STATEMENT: Data are available upon request from the corresponding author.Please read abstract in article.Sustainable Development (SATREPS) Program of JAPAN International Cooperation Agency (JICA)/Japan Agency; Climate and Earth Systems Science (ACCESS) program of National Research Foundation (NRF); Department of Science and Technology in South Africa (DST).https://www.mdpi.com/journal/healthcareGeography, Geoinformatics and Meteorolog

Perceptions of thermal comfort and coping mechanisms related to indoor and outdoor temperatures among participants living in rural villages in Limpopo province, South Africa

Global heating is considered one of the greatest threats to human health and well-being. Supporting human resilience to heating threats is imperative, but under-investigated. In response, this article reports a study that drew together results from quantitative data on perceptions of thermal comfort and mechanisms for coping with thermal discomfort among 406 households in a study in Giyani, Limpopo province. Indoor dwelling and outdoor temperatures were also analysed. Most participants perceived their dwellings to be too hot when it was hot outdoors. People relied on recommended heat health actions such as sitting outdoors in the shade or opening windows. While this agency is meaningful, resilience to climate change requires more than personal action. In light of the climate threats and climate-related disaster risks facing South Africa, an all-encompassing approach, including education campaigns, climate-proofed housing, access to basic services, and financial considerations that will help support resilient coping among South Africans, is urgently required.http://journals.sagepub.com/home/saphj2022Educational PsychologyGeography, Geoinformatics and Meteorolog

Indoor temperatures in patient waiting rooms in eight rural primary health care centers in Northern South Africa and the related potential risks to human health and wellbeing

Increased temperatures affect human health and vulnerable groups including infants, children, the elderly and people with pre-existing diseases. In the southern African region climate models predict increases in ambient temperature twice that of the global average temperature increase. Poor ventilation and lack of air conditioning in primary health care clinics, where duration of waiting time may be as long as several hours, pose a possible threat to patients seeking primary health care. Drawing on information measured by temperature loggers installed in eight clinics in Giyani, Limpopo Province of South Africa, we were able to determine indoor temperatures of waiting rooms in eight rural primary health care facilities. Mean monthly temperature measurements inside the clinics were warmer during the summer months of December, January and February, and cooler during the autumn months of March, April and May. The highest mean monthly temperature of 31.4 2.7 C was recorded in one clinic during February 2016. Maximum daily indoor clinic temperatures exceeded 38 C in some clinics. Indoor temperatures were compared to ambient (outdoor) temperatures and the mean difference between the two showed clinic waiting room temperatures were higher by 2–4 C on average. Apparent temperature (AT) incorporating relative humidity readings made in the clinics showed ‘realfeel’ temperatures were >4 C higher than measured indoor temperature, suggesting a feeling of ‘stuffiness’ and discomfort may have been experienced in the waiting room areas. During typical clinic operational hours of 8h00 to 16h00, mean ATs fell into temperature ranges associated with heat–health impact warning categories of ‘caution’ and ‘extreme caution’.Supplementary material: Figure S1: Indoor clinic temperatures, Figure S2: Mean indoor temperature experienced at each time point during each month for clinic 1, as an illustration of daily variation in indoor temperatures measurements, Figure S3: Indoor clinic apparent temperature, Figure S4: Differences between indoor clinic ambient apparent temperature and ambient temperature, Figure S5: Mean apparent temperature during clinic open hours of 8h00 to 16h00 compared to mean apparent temperature during all hours of the day, Table S1: Indoor clinic temperature and humidity measurements, Table S2: Ambient (outdoor) mean, minimum and maximum temperature and relative humidity measurements made at the Thohoyandou airport by month, Table S3: Monthly averages were compared for each clinic and the ambient (outdoor) temperature measurements and tested for statistically significant differences, Table S4: Mean apparent temperature (AT) per month for each clinic, with standard deviation and 1st and 99th percentiles.A South African Medical Research Council Flagship Grant, as well as funds from National Treasury under its Economic Competitiveness and Support Package, and a National Research Foundation Y-Rated Researchers grant.http://www.mdpi.com/journal/ijerpham2017Geography, Geoinformatics and Meteorolog

Exploring meteorological conditions and human health impacts during two dust storm events in Northern Cape province, South Africa: Findings and lessons learnt

Dust storms are meteorological hazards associated with several adverse health impacts including eye irritations, respiratory and cardiovascular disorders, and vehicular road accidents due to poor visibility. This study investigated relations between admissions from a large, public hospital that serves people living in Northern Cape and Free State provinces, South Africa during 2011 to 2017, and meteorological variables (temperature and air quality) during two dust storms, one in October 2014 (spring) and the second in January 2016 (summer), identified from the media as no repository of such events exists for South Africa. Distributed nonlinear lag analysis and wavelet transform analysis were applied to explore the relationships between hospital admissions for respiratory and cardiovascular diseases, eye irritation, and motor vehicle accidents; maximum temperature, and two air quality ‘proxy measures,’ aerosol optical depth and Ångström exponent, were used as groundbased air quality data were unavailable. Eye irritation was the most common dust-related hospital admission after both dust storm events. No statistically significant changes in admissions of interest occurred at the time of the two dust storm events, using either of the statistical methods. Several lessons were learnt. For this type of study, ground-based air quality and local wind data are required; alternative statistical methods of analysis should be considered; and a central dust storm repository would help analyze more than two events. Future studies in South Africa are needed to develop a baseline for comparison of future dust storm events and their impacts on human health.The South African Medical Research Councilhttps://www.mdpi.com/journal/atmosphereGeography, Geoinformatics and MeteorologySchool of Health Systems and Public Health (SHSPH

Classroom temperature and learner absenteeism in public primary schools in the Eastern Cape, South Africa

Children spend a significant proportion of their time at school and in school buildings. A healthy learning environment that supports children should be thermally conducive for learning and working. Here, we aimed to study the relations between indoor classroom temperatures and learner absenteeism as a proxy for children’s health and well-being. This one-year prospective study that spanned two calendar years (from June 2017 to May 2018) entailed measurement of indoor classroom temperature and relative humidity, calculated as apparent temperature (Tapp) and collection of daily absenteeism records for each classroom in schools in and around King Williams Town, Eastern Cape province, South Africa. Classroom characteristics were collected using a standardized observation checklist. Mean indoor classroom temperature ranged from 11 to 30 C, while mean outdoor temperature ranged from 6 C to 31 C during the sample period. Indoor classroom temperatures typically exceeded outdoor temperatures by 5 C for 90% of the study period. While multiple factors may influence absenteeism, we found absenteeism was highest at low indoor classroom Tapp (i.e., below 15 C). Absenteeism decreased as indoor Tapp increased to about 25 C before showing another increase in absenteeism. Classroom characteristics differed among schools. Analyses of indoor classroom temperature and absenteeism in relation to classroom characteristics showed few statistically significant relations—although not exceptionally strong ones—likely because of the multiple factors that influence absenteeism. However, given the possible relationship between indoor temperature and absenteeism, there is a learning imperative to consider thermal comfort as a fundamental element of school planning and design. Furthermore, additional research on factors besides temperature that affect learner absenteeism is needed, especially in rural areas.The South African Medical Research Councilhttps://www.mdpi.com/journal/ijerpham2022Geography, Geoinformatics and Meteorolog

Exploring rural hospital admissions for diarrhoeal disease, malaria, pneumonia, and asthma in relation to temperature, rainfall and air pollution using wavelet transform analysis

BACKGROUND : Climate variables impact human health and in an era of climate change, there is a pressing need to understand these relationships to best inform how such impacts are likely to change. OBJECTIVES : This study sought to investigate time series of daily admissions from two public hospitals in Limpopo province in South Africa with climate variability and air quality. METHODS : We used wavelet transform cross-correlation analysis to monitor coincidences in changes of meteorological (temperature and rainfall) and air quality (concentrations of PM2.5 and NO2) variables with admissions to hospitals for gastrointestinal illnesses including diarrhoea, pneumonia-related diagnosis, malaria and asthma cases. We were interested to disentangle meteorological or environmental variables that might be associated with underlying temporal variations of disease prevalence measured through visits to hospitals. RESULTS : We found preconditioning of prevalence of pneumonia by changes in air quality and showed that malaria in South Africa is a multivariate event, initiated by co-occurrence of heat and rainfall. We provided new statistical estimates of time delays between the change of weather or air pollution and increase of hospital admissions for pneumonia and malaria that are addition to already known seasonal variations. We found that increase of prevalence of pneumonia follows changes in air quality after a time period of 10 to 15 days, while the increase of incidence of malaria follows the co-occurrence of high temperature and rainfall after a 30-day interval. DISCUSSION : Our findings have relevance for early warning system development and climate change adaptation planning to protect human health and well-being.The SAMRC; this research was carried out for the iDEWS (infectious Diseases Early-Warning System) project supported by SATREPS (Science and Technology Research Partnership for Sustainable Development) Program of JICA (JAPAN International Cooperation Agency)/AMED (Japan Agency for Medical Research and Development) in Japan and the ACCESS (Alliance for Collaboration on Climate and Earth Systems Science) program of NRF (National Research Foundation) and DST (Department of Science and Technology in South Africa) as well as the Serbian Scientific Research Fund.http://www.elsevier.com/locate/scitotenvhj2022Geography, Geoinformatics and Meteorolog