Major climate change-induced risks to human health in South Africa

Climate change and its environmental and health effects from 2015 to 2022: A scoping review

Background

The rise in environmental pollutants has become a pressing global concern of international magnitude. Substantial evidence now demonstrates that escalating global temperatures and rising sea levels might exacerbate release of chemical pollutants into the environment which amplifies their toxicity. Existing research underscores the linkage between climate change and air pollution as driving forces, with increased mortality and morbidity.

Purpose of review

This review explores the reciprocal relationship between climate change and its impact on health, as well as the environment. We conducted an in-depth analysis of all relevant published studies, encompassing studies conducted across various regions worldwide, including the Eastern Mediterranean Regional Office (EMRO)1 region.

Summary

The environmental consequences of climate change have widespread impacts on various health systems and populations. Knowledge gaps remain in understanding the full scope of climate change effects, particularly through environmental pollution. The findings of this review highlight the need for global strategies to mitigate diverse health risks to protect from the growing threats of climate change.

The Health and Health Insurance Implications of Climate Change in Sub-Saharan Africa: A Narrative Review

Objectives

This paper aims to provide a narrative review of the implications of climate change on health and health insurance in sub-Saharan Africa.

Methods

A comprehensive research was employed to carry out a complete narrative study on the subject. Thus, since September 2022 we searched for literature on the relationships between climate change, health, and health insurance on PubMed over an unbounded period. By updating the research method, the outputs cover the period 2009-2024.

Results

Based on 19 key articles that focused on the implications of climate change for health and health insurance in sub-Saharan Africa, we highlight that climate change directly affects population health through climate-related disease. Indirectly, climate change affects health through its disruption of food availability and agriculture and through demographic shifts.

Conclusion

Finally, this narrative review suggests appropriate strategies to combat the health consequences of climate change and to improve universal health insurance systems.

A systematic literature review on the impact of climate change on the livelihoods of smallholder farmers in South Africa

Smallholder farmers in South Africa are increasingly vulnerable to the adverse effects of climate change, posing significant threats to their livelihoods and food security. This systematic literature review investigates the several impacts of climate change on smallholder farmers across the country. The literature review used a systematic approach to search for relevant research across three academic databases such as Google scholar, Consensus, and Zendy. Based on the inclusion criteria for the literature review, 261 articles were initially screened, and 35 articles were included in the systematic review. This process helped to identify the most relevant and high-quality studies on the topic. The data extracted from the 35 articles were analyzed and synthesized to identify the impact of climate change on the livelihoods of smallholder farmers. This helped to identify commonalities and differences across the literature, and to draw conclusions about the impact of climate change on the livelihoods of smallholder farmers. The study identified and examined the specific challenges faced by smallholder farmers, including the loss of livestock, reduced crop yields and heightened economic hardship. Additionally, the review explores the coping strategies employed by farmers to mitigate these challenges and adapt to the evolving climatic conditions. The findings highlight the urgent need for targeted interventions and support mechanisms aimed at enhancing the resilience of smallholder farmers and ensuring the long-term sustainability of agricultural practices amidst the challenges posed by climate change. Furthermore, the study provides valuable recommendations for policymakers, agriculturalists, and other stakeholders to address the identified issues and support smallholder farmers in adapting to climate change.

Assessment of SADC Countries' National Adaptation Planning Health Impacts Inclusion: A Thorough Review

Background: The impacts of climate change are recognised as a key challenge of the 21st century. By 2030, Sub-Saharan Africa is projected to have the globally highest burden of disease due to climate change. Objectives: This study aims to evaluate the strengths and weaknesses of the National Adaptation Plans (NAPs) of the Southern African Development Community (SADC), a sub-region under-represented at a global level, in addressing current and future climate change-related health impacts. It specifically assesses the NAPs of Botswana, Mozambique, Namibia, South Africa, and Zimbabwe. Methods: A thorough review was conducted, analysing articles, government reports, and national communications related to NAPs and climate change health outcomes in the selected countries. Sources were evaluated against pre-defined inclusion and exclusion criteria. Main findings: All five countries prioritised health in their NAPs; however, health departments were excluded from assessments in two of the countries. Although health surveillance and early warning systems were included in the NAPs, there was limited evidence of their integration into broader climate, health, economic, and labour policies. National climate change focal points were identified, but governance and implementation at district and local levels were not well-documented. This review highlighted a need for greater inclusion of Indigenous and locally led knowledge. Common barriers identified included the lack of data with appropriate frequency and scale. Governance and implementation difficulties were also identified in all five countries; these difficulties included both a lack of coordination and a lack of institutional capacity. These challenges, especially a lack of political will to address the compound impacts of altered climate and health on all earth systems, are also found at the regional level. Conclusions: National strategies and implementation programs in SADC countries need to be agile in their ability to scale and adapt, yet they also need to include measurable actions and timeframes. Given the shared climate and health trends and the interconnected socio-economic, environmental, and political landscape, there is significant potential for regional coordination to address cross-border climate change impacts and to optimise resource use.

Investigating the impact of air pollution and temperature changes on emergency admissions (cardiovascular + respiratory) disease in the city of Bojnord, northeastern Iran

Cardiovascular (CVD) + Respiratory diseases are recognized as the main cause of death worldwide. Fluctuations in temperature and air pollution have been reported as one of the most important causes of cardiovascular & respiratory diseases. Therefore, in the current study, we assessed the relationship between ambient air temperature and pollution on the number of total emergency hospital admission due to cardiovascular and respiratory conditions in the City of Bojnord, northeastern Iran. The meteorological data, including daily temperature, relative humidity and concentrations of five air pollutants CO, NO2, NOX SO2, and PM10 were obtained from online electronic sensors at the Bojnurd meteorological station from 21th March 2018 to 20th March 2020. Statistical analysis, penalized distributed lag non-linear method was applied using R Software. Also, sensitivity analysis test was calculated by using appropriate application. The results of the study revealed that the effect of higher and lower temperatures was observed immediately from the first day and the second week, respectively. Also result showed with increase and decrease temperature, significantly increased the risk of hospitalization by 36% (RR, 1.36; 95% CI (1), 0.95 to 1.95) and 17% (RR, 1.17; 95% CI (1), 0.88 to 1.55) until the lag 25th day, respectively. Based on the results, increasing temperature significantly increased the hospitalization rate of cardiopulmonary patients, but the effect of cold was not significant on the population as well as age and gender subgroups. Study have also proved that there is no significance correlation between air pollutant and Cardiovascular & respiratory diseases.

Assessing the impact of climatic variability on acute respiratory diseases across diverse climatic zones in South Africa

Acute respiratory diseases are a significant public health concern in South Africa, with climatic variables such as temperature and rainfall being key influencers. This study investigates the associations between these variables and the prevalence of acute respiratory diseases in Johannesburg, Cape Town, and Gqeberha (Port Elizabeth), representing distinct climatic zones. Spearman's correlation analyses showed negative correlations in Johannesburg for respiratory disease claims with maximum temperature (r = -0.12, p < 0.0001) and mean temperature (r = -0.13, p < 0.0001), and a negative correlation with daily rainfall (r = -0.12, p < 0.0001). Cape Town demonstrated a negative correlation with maximum temperature (r = -0.18, p < 0.0001) and a positive correlation with rainfall (r = 0.08, p < 0.0001). Utilizing Distributed Lag Non-linear Models (DLNM), the study revealed that in Johannesburg, the relative risk (RR) of respiratory claims increases notably at temperatures below 12 °C, and again at a Tmax between 16 and 23 °C. The risk escalates further at >30 °C, although with a considerable error margin. For Cape Town, a stable level of moderate RR is seen from Tmax 15-24 °C, with a significant increase in RR and error margin above 30 °C. In Gqeberha, the DLNM results are less definitive, reflecting the city's moderate climate and year-round rainfall. The RR of acute respiratory diseases did not show clear patterns with temperature changes, with increasing error margins outside the 22 °C threshold. These findings emphasize the imperative for region-specific public health strategies that account for the complex, non-linear influences of climate on respiratory health. This detailed understanding of the climate-health nexus provides a robust basis for enhancing public health interventions and future research directed at reducing the impacts of climate factors.

Understanding diarrhoeal diseases in response to climate variability and drought in Cape Town, South Africa: a mixed methods approach

BACKGROUND

The climate of southern Africa is expected to become hotter and drier with more frequent severe droughts and the incidence of diarrhoea to increase. From 2015 to 2018, Cape Town, South Africa, experienced a severe drought which resulted in extreme water conservation efforts. We aimed to gain a more holistic understanding of the relationship between diarrhoea in young children and climate variability in a system stressed by water scarcity.

METHODS

Using a mixed-methods approach, we explored diarrhoeal disease incidence in children under 5 years between 2010 to 2019 in Cape Town, primarily in the public health system through routinely collected diarrhoeal incidence and weather station data. We developed a negative binomial regression model to understand the relationship between temperature, precipitation, and relative humidity on incidence of diarrhoea with dehydration. We conducted in-depth interviews with stakeholders in the fields of health, environment, and human development on perceptions around diarrhoea and health-related interventions both prior to and over the drought, and analysed them through the framework method.

RESULTS

From diarrhoeal incidence data, the diarrhoea with dehydration incidence decreased over the decade studied, e.g. reduction of 64.7% in 2019 [95% confidence interval (CI): 5.5-7.2%] compared to 2010, with no increase during the severe drought period. Over the hot dry diarrhoeal season (November to May), the monthly diarrhoea with dehydration incidence increased by 7.4% (95% CI: 4.5-10.3%) per 1 °C increase in temperature and 2.6% (95% CI: 1.7-3.5%) per 1% increase in relative humidity in the unlagged model. Stakeholder interviews found that extensive and sustained diarrhoeal interventions were perceived to be responsible for the overall reduction in diarrhoeal incidence and mortality over the prior decade. During the drought, as diarrhoeal interventions were maintained, the expected increase in incidence in the public health sector did not occur.

CONCLUSIONS

We found that that diarrhoeal incidence has decreased over the last decade and that incidence is strongly influenced by local temperature and humidity, particularly over the hot dry season. While climate change and extreme weather events especially stress systems supporting vulnerable populations such as young children, maintaining strong and consistent public health interventions helps to reduce negative health impacts.

Defining the South African Acute Respiratory Infectious Disease Season

The acute respiratory infectious disease season, or colloquially the "flu season", is defined as the annually recurring period characterized by the prevalence of an outbreak of acute respiratory infectious diseases. It has been widely agreed that this season spans the winter period globally, but the precise timing or intensity of the season onset in South Africa is not well defined. This limits the efficacy of the public health sector to vaccinate for influenza timeously and for health facilities to synchronize efficiently for an increase in cases. This study explores the statistical intensity thresholds in defining this season to determine the start and finish date of the acute respiratory infectious disease season in South Africa. Two sets of data were utilized: public-sector hospitalization data that included laboratory-tested RSV and influenza cases and private-sector medical insurance claims under ICD 10 codes J111, J118, J110, and J00. Using the intensity threshold methodology proposed by the US CDC in 2017, various thresholds were tested for alignment with the nineteen-week flu season as proposed by the South African NICD. This resulted in varying thresholds for each province. The respiratory disease season commences in May and ends in September. These findings were seen in hospitalization cases and medical insurance claim cases, particularly with influenza-positive cases in Baragwanath hospital for the year 2019. These statistically determined intensity thresholds and timing of the acute respiratory infectious disease season allow for improved surveillance and preparedness among the public and private healthcare.

Air quality and health benefits of increasing carbon mitigation tech-innovation in China

Most studies on the short-term local benefits of carbon mitigation technologies on air quality improvement and health focus on specific technologies such as biofuels or carbon sequestration technologies, while ignoring the overall role of the growing scale of low-carbon technologies. Based on STIRPAT model and EKC hypothesis, this paper takes 30 provinces in China from 2004 to 2016 as research samples. We builded the panel double fixed effect model to empirical analysis of climate change on carbon mitigation tech-innovation suppressing the influence of haze pollution, on this basis, the mediating effect model was used to explore the mediation function of industrial structure and energy structure. Meanwhile, we drawed on the existing studies on air quality and health benefits, and quantify the co-benefits of carbon mitigation tech-innovation on health through the equivalent substitution formula. It shows that a 1% increase in the number of low-carbon patent applications can reduce haze pollution by 0.066%. According to this estimate, to 2029, China's carbon mitigation tech-innovation could reduce PM2.5 concentration to 15 μg/m³ preventing 5.597 million premature deaths. Moreover, carbon mitigation tech-innovation can also indirectly inhibit haze pollution by triggering more systematic economic structure changes such as energy and industrial structure. Additionally, we found that the role of gray tech-innovation (GT) related to improving the efficiency of fossil energy is stronger than that of clean technology (CT) related to the use of renewable energy. This suggests that for a large economy such as China, where coal is still the dominant source of energy consumption, the short-term local benefits of improving air quality and health through the use of gray tech-innovation to improve energy and industrial structure are still important to balance the cost of carbon mitigation.

Meteorological Drought Variability and Its Impact on Wheat Yields across South Africa

Drought is one of the natural hazards that have negatively affected the agricultural sector worldwide. The aims of this study were to track drought characteristics (duration (DD), severity (DS), and frequency (DF)) in South Africa between 2002 and 2021 and to evaluate its impact on wheat production. Climate data were collected from the South African Weather Service (SAWS) along with wheat yield data from the Department of Agriculture, Forestry and Fisheries (2002-2021). The standard precipitation index (SPI) was calculated on 3-, 6-, 9-, and 12-month time scales, and the trend was then tracked using the Mann-Kendall (MK) test. To signify the climatic effects on crop yield, the standardized yield residual series (SYRS) was computed along with the crop-drought resilience factor (CR) on a provincial scale (2002-2021). The output of the SPI analysis for 32 stations covering all of South Africa indicates a drought tendency across the country. On a regional scale, western coastal provinces (WES-C and NR-C) have been more vulnerable to meteorological droughts over the past 20 years. Positive correlation results between SYRS and wheat yield indicate that the WES-C province was highly influenced by drought during all stages of wheat growth (Apr-Nov). Historical drought spells in 2003, 2009, and 2010 with low CR = 0.64 caused the province to be highly impacted by the negative impacts of droughts on yield loss. Overall, drought events have historically impacted the western part of the country and dominated in the coastal area. Thus, mitigation plans should be commenced, and priority should be given to this region. These findings can assist policymakers in budgeting for irrigation demand in rainfed agricultural regions.

Plant Nutrition for Human Health: A Pictorial Review on Plant Bioactive Compounds for Sustainable Agriculture

Is there any relationship between plant nutrition and human health? The overall response to this question is very positive, and a strong relationship between the nutrition of plants and humans has been reported in the literature. The nutritional status of edible plants consumed by humans can have a negative or positive impact on human health. This review was designed to assess the importance of plant bioactive compounds for human health under the umbrella of sustainable agriculture. With respect to the first research question, it was found that plant bioactives (e.g., alkaloids, carotenoids, flavonoids, phenolics, and terpenoids) have a crucial role in human health due to their therapeutic benefits, and their potentiality depends on several factors, including botanical, environmental, and clinical attributes. Plant bioactives could be produced using plant tissue culture tools (as a kind of agro-biotechnological method), especially in cases of underexploited or endangered plants. Bioactive production of plants depends on many factors, especially climate change (heat stress, drought, UV radiation, ozone, and elevated CO2), environmental pollution, and problematic soils (degraded, saline/alkaline, waterlogged, etc.). Under the previously mentioned stresses, in reviewing the literature, a positive or negative association was found depending on the kinds of stress or bioactives and their attributes. The observed correlation between plant bioactives and stress (or growth factors) might explain the importance of these bioactives for human health. Their accumulation in stressed plants can increase their tolerance to stress and their therapeutic roles. The results of this study are in keeping with previous observational studies, which confirmed that the human nutrition might start from edible plants and their bioactive contents, which are consumed by humans. This review is the first report that analyzes this previously observed relationship using pictorial presentation.