Estimating the burden of disease attributable to ambient air pollution (ambient PM2.5 and ambient ozone) in South Africa for 2000, 2006 and 2012.

Background: Globally, a growing body of research has shown that ambient air pollution is one of the most critical environmental issues, especially in relation to human health. Exposure to ambient air pollution leads to serious health conditions such as lower respiratory infections, cancers, diabetes mellitus type 2, ischaemic heart disease, stroke and chronic obstructive pulmonary disease. Objectives: To estimate the burden of disease attributable to ambient air pollution in South Africa (SA) for the years 2000, 2006 and 2012. Methods: Comparative risk assessment method was used to determine the burden of disease due to two pollutants (particulate matter (PM2.5) and ambient ozone). Regionally optimised fully coupled climate chemistry models and surface air pollution observations were used to generate concentrations of PM2.5 and ozone for each SA Census Small Area Level, for the year 2012. For 2000 and 2006, population-weighted PM2.5and ozone were estimated, based on the 2012 results. Following the identification of disease outcomes associated with particulate matter with aerodynamic diameter <2.5 µm (PM2.5) and ozone exposure, the attributable burden of disease was estimated for 2000, 2006 and 2012. Furthermore, for the year 2012, the burden of disease attributable to ambient air pollution exposure was computed at provincial levels. Results: In 2012, approximately 97.6% of people in SA were exposed to PM2.5 at levels above the 2005 World Health Organization guideline: 10 µg/m3 annual mean. From 2000 to 2012, population-weighted annual average PM2.5 increased from 26.6 µg/m3 to 29.7 µg/m3, and ozone 6-month high 8-hour daily maximum increased from 64.4 parts per billion (ppb) to 72.1 ppb. At a national scale, in the year 2000, 15 619 (95% uncertainty interval (UI) 8 958 - 21 849) deaths were attributed to PM2.5 exposure, while 1 326 (95% UI 534 - 1 885) deaths were attributed to ozone. In 2006, an estimated 19 672 deaths (95% UI 11 526 - 27 086) were attributed to PM2.5, and a further 1 591 deaths (95% UI 651 - 2 236) to ozone exposure. In 2012, deaths attributed to PM2.5 were 19 507 (95% UI 11 318 - 27 111), and to ozone 1 734 (95% UI 727 - 2 399). Additionally, population-weighted provincial scale analysis showed that Gauteng Province had the highest number of attributable deaths due to both PM2.5 and ozone in 2012. Conclusion: The study showed that ambient air pollution exposure is an important health risk in SA, requiring both short- and long-term intervention. In the short term, the SA Ambient Air Quality Standards and industrial minimum emissions standards need to be enforced. In the longer term, to reduce air pollution and the associated disease burden, the combustion of fossil fuels as a source of energy for power generation and transportation, as well as industrial and domestic uses, needs to be replaced with clean renewable energy sources. In addition to local measures, when the southern African prevalent anticyclonic air dynamics that transport regionally emitted pollutants into SA (especially from biomass burning) are considered, it is also advisable to establish long-term regional co-operation in reducing air pollution.

Estimating the burden of disease attributable to household air pollution from cooking with solid fuels in South Africa for 2000, 2006 and 2012.

BACKGROUND: Household air pollution (HAP) due to the use of solid fuels for cooking is a global problem with significant impacts on human health, especially in low- and middle-income countries. HAP remains problematic in South Africa (SA). While electrification rates have improved over the past two decades, many people still use solid fuels for cooking owing to energy poverty. OBJECTIVES: To estimate the disease burden attributable to HAP for cooking in SA over three time points: 2000, 2006 and 2012. METHODS: Comparative risk assessment methodology was used. The proportion of South Africans exposed to HAP was assessed and assigned the estimated concentration of particulate matter with a diameter <2.5 µg/m3 (PM2.5) associated with HAP exposure. Health outcomes and relative risks associated with HAP exposure were identified. Population-attributable fractions and the attributable burden of disease due to HAP exposure (deaths, years of life lost, years lived with disability and disability-adjusted life years (DALYs)) for SA were calculated. Attributable burden was estimated for 2000, 2006 and 2012. For the year 2012, we estimated the attributable burden at provincial level. RESULTS: An estimated 17.6% of the SA population was exposed to HAP in 2012. In 2012, HAP exposure was estimated to have caused 8 862 deaths (95% uncertainty interval (UI) 8 413 - 9 251) and 1.7% (95% UI 1.6% - 1.8%) of all deaths in SA, respectively. Loss of healthy life years comprised 208 816 DALYs (95% UI 195 648 - 221 007) and 1.0% of all DALYs (95% UI 0.95% - 1.0%) in 2012, respectively. Lower respiratory infections and cardiovascular disease contributed to the largest proportion of deaths and DALYs. HAP exposure due to cooking varied across provinces, and was highest in Limpopo (50.0%), Mpumalanga (27.4%) and KwaZulu-Natal (26.4%) provinces in 2012. Age standardised burden measures showed that these three provinces had the highest rates of death and DALY burden attributable to HAP. CONCLUSION: The burden of disease from HAP due to cooking in SA is of significant concern. Effective interventions supported by legislation and policy, together with awareness campaigns, are needed to ensure access to clean household fuels and improved cook stoves. Continued and enhanced efforts in this regard are required to ensure the burden of disease from HAP is curbed in SA.

Overview.

BACKGROUND: South Africa (SA) faces multiple health challenges. Quantifying the contribution of modifiable risk factors can be used to identify and prioritise areas of concern for population health and opportunities for health promotion and disease prevention interventions. OBJECTIVE: To estimate the attributable burden of 18 modifiable risk factors for 2000, 2006 and 2012. METHODS: Comparative risk assessment (CRA), a standardised and systematic approach, was used to estimate the attributable burden of 18 risk factors. Risk exposure estimates were sourced from local data, and meta-regressions were used to model the parameters, depending on the availability of data. Risk-outcome pairs meeting the criteria for convincing or probable evidence were assessed using relative risks against a theoretical minimum risk exposure level to calculate either a potential impact fraction or population attributable fraction (PAF). Relative risks were sourced from the Global Burden of Disease, Injuries, and Risk Factors (GBD) study as well as published cohort and intervention studies. Attributable burden was calculated for each risk factor for 2000, 2006 and 2012 by applying the PAF to estimates of deaths and years of life lost from the Second South African National Burden of Disease Study (SANBD2). Uncertainty analyses were performed using Monte Carlo simulation, and age-standardised rates were calculated using the World Health Organization standard population. RESULTS: Unsafe sex was the leading risk factor across all years, accounting for one in four DALYs (26.6%) of the estimated 20.6 million DALYs in 2012. The top five leading risk factors for males and females remained the same between 2000 and 2012. For males, the leading risks were (in order of descending rank): unsafe sex; alcohol consumption; interpersonal violence; tobacco smoking; and high systolic blood pressure; while for females the leading risks were unsafe sex; interpersonal violence; high systolic blood pressure; high body mass index; and high fasting plasma glucose. Since 2000, the attributable age-standardised death rates decreased for most risk factors. The largest decrease was for household air pollution (-41.8%). However, there was a notable increase in the age-standardised death rate for high fasting plasma glucose (44.1%), followed by ambient air pollution (7%). CONCLUSION: This study reflects the continued dominance of unsafe sex and interpersonal violence during the study period, as well as the combined effects of poverty and underdevelopment with the emergence of cardiometabolic-related risk factors and ambient air pollution as key modifiable risk factors in SA. Despite reductions in the attributable burden of many risk factors, the study reveals significant scope for health promotion and disease prevention initiatives and provides an important tool for policy makers to influence policy and programme interventions in the country.

Demographic and socio-economic risk factors associated with self-reported TB.

BACKGROUND: The infectiousness of Mycobacterium tuberculosis is known to be shaped by the human environment, with research showing positive associations with poverty, homelessness and overcrowding, among other factors. In this study, the focus is primarily on environmental health risks for TB, particularly on those associated with sociodemographic and household living conditions in South Africa.METHODS: Data for this study were collected between 2014 and 2019 from a number of sites implementing community-oriented primary care (COPC) in the Gauteng Province of the country. Community health workers (CHWs) used AitaHealthtm, a custom-built mobile information management application, to obtain data on the TB status and environmental conditions of households. Statistical models were used to determine associations between various demographic, socio-economic and environmental risk factors, and TB.RESULTS: Approximately 12,503 TB cases were reported among 7,769 households. Substance use and male-headed households were found to have significant associations in households with at least one individual with TB. Overcrowding, as well as lack of access to piped water and adequate sanitation were also found to be positively associated with a 'TB-household.´CONCLUSION: Improvements in housing and services, particularly the provision of piped water and reticulated flush toilets, are needed to control and prevent TB in South Africa.

The incidence of melanoma in South Africa: An exploratory analysis of National Cancer Registry data from 2005 to 2013 with a specific focus on melanoma in black Africans.

BACKGROUND: Melanoma is an aggressive skin cancer with poor survival when diagnosed late. There are important differences in clinical and histological features of melanoma and disease outcomes in people with darker skin types. METHODS: A retrospective review of data captured by the National Cancer Registry (NCR) of South Africa (SA) was performed for 2005 - 2013. Data on patient numbers, demography, location and biological features were analysed for all records. Closer analysis of melanoma of the limbs reported in black Africans was done after manually collecting this information from original reports. RESULTS: With 11 784 invasive melanomas reported to the NCR, the overall incidence of melanoma for SA was 2.7 per 100 000. Males (51%), individuals aged ≥60 years (48%) and the anatomical sites of lower limb (36%) and trunk (27%) were most commonly affected. Melanoma incidences in the white and black populations were 23.2 and 0.5 per 100 000, respectively. Most cases were diagnosed at private pathology laboratories (73%). Superficial spreading melanoma (47%) and nodular melanoma (20%) predominated. Among 878 black Africans diagnosed in the public sector with melanoma of the limbs, females (68%) and individuals aged ≥60 years (61%) were most commonly affected. Lower-limb lesions (91%) and acral lentiginous melanoma (65%) predominated, with 74% of cases affecting the foot and 62% of cases presenting with a Breslow depth >4 mm. CONCLUSIONS: This study provides up-to-date NCR incidence and demographic data on melanoma and highlights the neglected research gaps in relation to melanoma in black Africans to provide evidence needed to address health disparities in overlooked population groups.

Gathering the evidence and identifying opportunities for future research in climate, heat and health in South Africa: The role of the South African Medical Research Council.

BACKGROUND: A changing climate is likely to have widespread and varying impacts on ecosystems and human health. South Africa (SA) is particularly vulnerable to the impacts of climate change, given the projected increases in temperature, and changes in the amount and patterns of rainfall. Moreover, SA's vulnerability is exacerbated by extreme inequality and poverty. To prepare for the impacts of climate change and to ensure timeous adaptation, a perspective is given on essential heat and health research in the country. Objectives. To gather studies conducted by the South African Medical Research Council (SAMRC)'s Environment and Health Research Unit (EHRU) to illustrate the range of possible research key areas in the climate, heat and health domain and to present future research priorities. Methods. Studies conducted by the SAMRC's EHRU were gathered and used to illustrate the range of possible research key areas in the climate, heat and health domain. Using national and international published and grey literature, and tapping into institutional research experiences, an overview of research findings to date and future research priorities were developed. Results. Heat and health-related research has focussed on key settings, for example, schools, homes and outdoor work places, and vulnerable groups such as infants and children, the elderly and people with pre-existing diseases. The need to address basic needs and services provision was emphasised as an important priority. Conclusions. High and low temperatures in SA are already associated with mortality annually; these impacts are likely to increase with a changing climate. Critical cross-sectoral research will aid in understanding and preparing for temperature extremes in SA.

Neonatal, infant and child health in South Africa: Reflecting on the past towards a better future.

Although the neonatal mortality rate in South Africa (SA) has remained stagnant at 12 deaths per 1 000 live births, the infant and under-5 mortality rates have significantly declined since peaking in 2003. Policy changes that have influenced this decline include policies to prevent vertical HIV transmission, earlier treatment of children living with HIV, expanded immunisation policies, strengthening breastfeeding practices, and health policies to contain tobacco and sugar use. The Sustainable Development Goals (2016 - 2030) have shifted the focus from keeping children alive, as expressed in the Millennium Development Goals (1990 - 2015), to achieving optimal health through the 'Survive, thrive and transform' global agenda. This paper focuses on important remaining causes of childhood mortality and morbidity in SA, specifically respiratory illness, environmental pollution, tuberculosis, malnutrition and vaccine-preventable conditions. The monitoring of maternal and child health (MCH) outcomes is crucial, and has improved in SA through both the District Health Information and Civil Registration and Vital Statistics systems, although gaps remain. Intermittent surveys and research augment the routinely collected data. However, availability and use of local data to inform quality and effectiveness of care is critical, and this requires ownership at the collection point to facilitate local redress. Potential game changers to improve MCH outcomes include mobile health and community-based interventions. In SA, improved MCH remains a crucial factor for human capital development. There is a pressing need to focus beyond childhood mortality and to ensure that each child thrives.

Assessing a portable, real-time display handheld meter with UV-A and UV-B sensors for potential application in personal sun exposure studies.

BACKGROUND: Observing accurate real-time measurements of solar ultraviolet radiation (UVR) levels is important since personal excess sun exposure is associated with skin cancers. Handheld measurement devices may be helpful but their accuracy is unknown. We compare a portable, science-grade solar UVR monitoring device against two fixed, science-grade solar UVR instruments. METHODS: Instruments were (1) a fixed Solar Light 501 UV-B biometer to measure UV-B; (2) a fixed Kipp and Zonen radiometer used to measure UV-A and UV-B; and (3) Goldilux ultraviolet probes which are commercially available portable devices. Two different probes were used, one measured UV-A and the other UV-B radiation. The Goldilux probes were levelled and secured next to the UV-B biometer. Between 10:00 and 14:40 UTC+2, the UV-B biometer was set to record at 10-minute intervals and measurements by the Goldilux probes were manually taken simultaneously. Results were compared for all data and by solar zenith angle (SZA) ranges. RESULTS: The Goldilux UV-B probe measured UV-B relatively well in its diurnal pattern, however, its readings were ~77% higher than those made by the UV-B biometer. While UV-A measurements from the Goldilux UV-A probe and those from the radiometer were in relatively good agreement in pattern, the radiometer read ~47% higher than the Goldilux UV-A probe. UV-B data from Goldilux UV-B probe had a moderately strong correlation with UV-B biometer data for small SZAs; conversely, for UV-A, the Goldilux UV-A probe had a strong correlation with the UV-A radiometer data for large SZAs. CONCLUSION: Handheld devices may be useful to provide real-time readings of solar UVR patterns, however, to achieve synchronicity in the magnitude of readings to those made by science-grade fixed instruments, devices may need to be used during certain times of the day and in clear-sky conditions which may not be practical in personal exposure studies.

Bibliometric trends of South African environmental health articles between 1998 and 2015: Making local research visible and retrievable.

BACKGROUND: South Africa (SA) has to grapple with multiple burdens of disease for which environmental factors have a role to play in both causation and prevention. This article describes a bibliometric review of environmental health indexed literature for SA over an 18-year period. OBJECTIVES: To provide an overview of the nature of SA-based published environmental health indexed research and to identify search challenges, frequently researched topics, and gaps and opportunities for future research. METHODS: The Web of Science, PubMed and Science Direct were used to search for original, peer-reviewed and review articles with the inclusion criteria 'environmental health' and 'South Africa' available online and published between 1998 and 2015, inclusively. RESULTS: A total of 230 journal articles were included in the bibliometric analysis. The highest number of articles (n=54) was published in 2015. The majority of the first authors were affiliated with SA institutions (n=160, 69.5%). For the articles where funding was explicitly declared (n=148), the three most frequently occurring agencies that funded the published research were the National Research Foundation in SA (n=17), the South African Medical Research Council (n=13) and the Water Research Commission (n=9). There was little inter-annual/environmental health category variation over time owing to the relatively small sample size. The largest number of retrieved journal articles was in the area of environmental pollution control (n=76), followed by environmental health lifestyle and behaviour-related topics (n=42) and then water monitoring (n=26). CONCLUSIONS: Despite the research needed to solve large environmental health challenges in SA, environmental health was only used as a keyword in title, author keywords or abstract for 230 SA-based studies over an 18-year period. This makes it extremely difficult for environmental health research to be located and used to inform the profession as well as the research agenda. Several issues that environmental health practitioners are typically tasked to implement and monitor are not indexed as environmental health topics. The need for authors to use 'environmental health' as a keyword is emphasised, particularly if research is to inform decision-making and policy support, as well as guide future research in the country.

The influence of HIV infection on the age dependence of squamous cell carcinoma of the skin in South Africa.

BACKGROUND: Cancer incidence typically increases with age, but it is not known whether ethnic characteristics influence the age dependence of squamous cell carcinoma of the skin (SCC). OBJECTIVES: (i) To determine the age dependence of SCC in the black African, coloured and white population groups of South Africa (SA); and (ii) to show whether any differences in the rate of change of age dependence could be influenced by diversity in behaviour and lifestyle, especially with regard to the prevalence of HIV infection, rather than by a fundamental variation in cancer biology between the populations. METHODS: Linear regression analysis was applied to the logarithm of the age-specific incidence rates for SCC v. the logarithm of age between 35 and 74 years. The slopes of the regression (age exponent) were compared for each subset of gender, population group and year of diagnosis (between 2000 and 2010). RESULTS: The most notable feature was the low value of the age exponent in both male and female black African compared with the white and coloured populations. This finding could be explained in part by the difference in the prevalence of HIV infection in the black African population group compared with the white and coloured population groups. CONCLUSIONS: The prevalence of HIV infection in black Africans in SA tends to decrease the apparent age component in SCC compared with the white and coloured population groups. Other factors relating to lifestyle and behaviour that differ between the population groups are also likely to influence the age component in SCC.

Bibliometric trends of South African environmental health articles between 1998 and 2015: Making local research visible and retrievable

Background. South Africa (SA) has to grapple with multiple burdens of disease for which environmental factors have a role to play in both causation and prevention. This article describes a bibliometric review of environmental health indexed literature for SA over an 18-year period.Objectives. To provide an overview of the nature of SA-based published environmental health indexed research and to identify search challenges, frequently researched topics, and gaps and opportunities for future research.Methods. The Web of Science, PubMed and Science Direct were used to search for original, peer-reviewed and review articles with the inclusion criteria 'environmental health' and 'South Africa' available online and published between 1998 and 2015, inclusively.Results. A total of 230 journal articles were included in the bibliometric analysis. The highest number of articles (n=54) was published in 2015. The majority of the first authors were affiliated with SA institutions (n=160, 69.5%). For the articles where funding was explicitly declared (n=148), the three most frequently occurring agencies that funded the published research were the National Research Foundation in SA (n=17), the South African Medical Research Council (n=13) and the Water Research Commission (n=9). There was little inter-annual/environmental health category variation over time owing to the relatively small sample size. The largest number of retrieved journal articles was in the area of environmental pollution control (n=76), followed by environmental health lifestyle and behaviour-related topics (n=42) and then water monitoring (n=26).Conclusions. Despite the research needed to solve large environmental health challenges in SA, environmental health was only used as a keyword in title, author keywords or abstract for 230 SA-based studies over an 18-year period. This makes it extremely difficult for environmental health research to be located and used to inform the profession as well as the research agenda. Several issues that environmental health practitioners are typically tasked to implement and monitor are not indexed as environmental health topics. The need for authors to use 'environmental health' as a keyword is emphasised, particularly if research is to inform decision-making and policy support, as well as guide future research in the country

The influence of HIV infection on the age dependence of squamous cell carcinoma of the skin in South Africa

Background. Cancer incidence typically increases with age, but it is not known whether ethnic characteristics influence the age dependence of squamous cell carcinoma of the skin (SCC).Objectives. (i) To determine the age dependence of SCC in the black African, coloured and white population groups of South Africa (SA); and (ii) to show whether any differences in the rate of change of age dependence could be influenced by diversity in behaviour and lifestyle, especially with regard to the prevalence of HIV infection, rather than by a fundamental variation in cancer biology between the populations.Methods. Linear regression analysis was applied to the logarithm of the age-specific incidence rates for SCC v. the logarithm of age between 35 and 74 years. The slopes of the regression (age exponent) were compared for each subset of gender, population group and year of diagnosis (between 2000 and 2010).Results. The most notable feature was the low value of the age exponent in both male and female black African compared with the white and coloured populations. This finding could be explained in part by the difference in the prevalence of HIV infection in the black African population group compared with the white and coloured population groups.Conclusions. The prevalence of HIV infection in black Africans in SA tends to decrease the apparent age component in SCC compared with the white and coloured population groups. Other factors relating to lifestyle and behaviour that differ between the population groups are also likely to influence the age component in SCC

Primary cutaneous malignancies in the Northern Cape Province of South Africa: A retrospective histopathological review.

BACKGROUND: Excessive sun exposure and a high prevalence of HIV increase skin cancer risk in South Africa (SA). OBJECTIVE: To describe the nature and extent of skin cancers presenting in the public and private health sectors of the Northern Cape Province of SA. METHODS: A retrospective analysis of histologically confirmed new primary cutaneous malignancies from 1 January 2008 to 31 December 2012 was conducted using public and private health sector databases. Types, quantity and distribution of common invasive malignancies by population group, age, gender, anatomical site and health sector were explored. One-year cumulative incidence was calculated and logistic regression models were used to analyse incidence and melanoma thickness trends. RESULTS: A total of 4 270 biopsies (13 cutaneous malignancies) were identified. The commonest was squamous cell carcinoma (SCC), followed by basal cell carcinoma, Kaposi's sarcoma (KS), cutaneous malignant melanoma (CMM) and basosquamous carcinoma, in descending order. The odds of a white male developing SCC increased by 8% each year (odds ratio (OR) 1.08, 95% confidence interval (CI) 1.01 - 1.15; p=0.022), while the odds of a black male developing SCC and KS decreased by 9% (OR 0.91, 95% CI 0.84 - 0.99; p=0.033) and 18% (OR 0.82, 95% CI 0.70 - 0.97; p=0.022), respectively, each year. SCC and CMM were diagnosed at more advanced stages in the public than in the private healthcare sector. CMM is being detected earlier, as indicated by low-stage depth increasing by 72% annually (OR 1.72, 95% CI 1.04 - 3.01; p=0.042). CONCLUSIONS: Results suggest that reported skin cancer patterns are changing. There is a need for further research and equitable appropriation of financial resources and effort towards developing primary skin cancer prevention initiatives in SA.

In multiple situational light settings, visual observation for skin colour assessment is comparable with colorimeter measurement.

BACKGROUND: Finding inexpensive and reliable techniques for assessing skin colour is important, given that it is related to several adverse human health outcomes. Visual observation is considered a subjective approach assessment and, even when made by trained assessor, concern has been raised about the need for controlled lighting in the study venue. The aim of this study is to determine whether visual skin colour assessments correlate with objective skin colour measurements in study venues with different lighting types and configurations. METHODS: Two trained investigators, with confirmed visual acuity, visually classified the inner, upper arm skin colour of 556 adults using Munsell(®) colour classifications converted to Individual Typology Angle (°ITA) values based on published data. Skin colour at the same anatomic site was also measured using a colorimeter. Each participant was assessed in one of 10 different buildings, each with a different study day. Munsell(®) -derived °ITA values were compared to colorimeter °ITA values for the full sample and by building/day. RESULTS: We found a strong positive, monotonic correlation between Munsell(®) derived °ITA values and colorimeter °ITA values for all participants (Spearman ρ = 0.8585, P < 0.001). Similar relationships were found when Munsell(®) and colorimeter °ITA values were compared for participants assessed in the same building for all 10 buildings (Spearman ρ values ranged from 0.797 to 0.934, all correlations were statistically significant at P < 0.001). CONCLUSION: It is possible to visually assess individual skin colour in multiple situational lighting settings and retrieve results that are comparable with objective measurements of skin colour. This was true for individuals of varying population groups and skin pigmentation.