Residential biomass combustion in rural communities is recognised as a major contributor to air pollution, representing the second-largest source of gaseous emissions and the primary source of atmospheric particulate matter. In many African countries, including South Africa, residential emission inventories and air quality assessments rely largely on international emission factors (EFs), introducing considerable uncertainty due to regional differences in fuel characteristics, combustion technologies, and household energy-use practices. Generating locally derived EFs is therefore essential for improving the accuracy of emission inventories and supporting effective air quality management and climate policy development. This study quantified the EFs of CO₂, CO, NO, SO₂, and PM₁₀ from the combustion of the 12 predominantly preferred fuelwood species used for household energy in rural Limpopo Province, South Africa. Controlled combustion experiments were conducted using a traditional three-legged cookstove in a simulated village kitchen under laboratory conditions. The mean EFs determined for CO₂, CO, NO, SO₂, and PM₁₀ were 1389 ± 149, 131.38 ± 91.4, 1.22 ± 0.63, 5.16 ± 4.9, and 64.7 ± 76.3 g kg⁻¹, respectively. Modified combustion efficiency (MCE) exhibited a statistically significant negative association with the EFs of CO and SO₂, indicating that lower combustion efficiency was associated with higher emissions of these pollutants. In contrast, fuel moisture content was not significantly associated with the EFs of CO₂, NO, or PM₁₀, while no statistically significant relationship was observed between fuel nitrogen (N) content and NO EFs. Furthermore, no statistically significant differences were detected among the investigated fuelwood species in the individual EFs of CO₂, CO, NO, SO₂, and PM₁₀. This study provides the first laboratory-derived, species-specific EF dataset for the predominantly preferred fuelwood species used in rural Limpopo Province. The findings reduce uncertainties associated with the application of international default EFs and provide a robust basis for improving residential biomass emission inventories, air quality modelling, and the development of evidence-based air pollution mitigation and climate management strategies in South Africa and other regions with similar household energy-use patterns.

This study examines the biomass burning vertical distribution and aerosol loading in relation to the El Niño Southern Oscillation (ENSO) during a 26-year period, using an innovative machine learning method. The use of machine learning in the present work is twofold: i) to build a long aerosol optical depth (AOD) hybrid-dataset (1998-2024) by combining sunphotometer observations in Skukuza with statistical model predictions and ii) to identify the most relevant variables among those observed during the measurement campaigns. The analysis of the aerosol variability reveals that the three most significant variables are ENSO, the Fire Radiation Power (FRP) and the Black Carbon (BC). This corroborates the fact that biomass burning activity plays a key role in the variability of AOD in Skukuza. We highlighted that one significant factor that supports the influence of El Niño on the variability of the aerosols produced by biomass burning activity is the intensity of the La Niña episode that precedes it. In contrast, the impact of a La Niña episode on the variability of biomass burning aerosols is independent of the strength of the El Niño episode that precedes it. Our findings are consistent with work published during the SAFARI 92 and 2000 campaigns. We conclude that the machine learning method employed in this work enhanced the statistical model's understanding of how ENSO affects AOD variability when compared to previous studies using similar observations

Ambient air pollution is a growing public health concern in South Africa. However, the health impacts of ambient air pollution in the country remain largely unquantified, a gap that is consistently reflected in global systematic reviews. This study investigates the association between ambient air pollution and cause-specific mortality, cardiovascular (CVD), and respiratory disease (RD), in Limpopo province, South Africa, over a decade from 2011 to 2020, with the aim of unravelling population and seasonal vulnerability. Daily mortality data were sourced from Statistics South Africa, while ambient air pollutant concentrations (PM₁₀, PM₂.₅, SO₂, NO₂, and O₃) were retrieved from the South African Air Quality Information System. Time-series and quasi-Poisson regression models within a generalized additive model framework were employed to estimate relative risks (RRs) per interquartile range (IQR) increase in pollutant concentrations, adjusting for seasonality and meteorological covariates. A total of 73,167 CVD and 62,248 RD deaths were recorded during the study period. PM and O₃ emerged as the strongest predictors of excess mortality, with O₃ particularly linked to CVD mortality and PM to RD mortality. An interquartile range increase in O₃ was associated with a 0.3–7.5

This study provides the first comprehensive characterisation of the chemical and mineralogical composition of mineral dust from Southern Africa, a major global dust source with significant impacts on regional climate and marine ecosystems. Laboratory-generated dust aerosol samples were produced using soils collected from key natural and emerging anthropogenic dust sources in Southern Africa. The chemical properties of mineral dust across Southern Africa were characterised using the elemental ratios Si/Al, (Ca+Mg)/Al, and K/Al, together with clay content. These indicators distinguish dust aerosols originating from arid western coastal areas from those originating from more humid eastern inland regions. They also provide information about the source-area environments and sediment weathering regimes, which are influenced by current and past temperature and precipitation patterns. The results of this study indicate that Southern African dust contains essential micronutrients such as iron (Fe), phosphorus (P) and manganese (Mn), which can become soluble and bioaccessible during atmospheric transport. In particular, emerging anthropogenic dust can be distinguished by its high content of certain nutrients. This affects the biogeochemistry of nearby and remote marine ecosystems, including the Southern Ocean. Southern African dust also contains higher levels of carbonates than Northern African dust sources, which can promote heterogeneous reactions and particle ageing, and contribute to cloud condensation nuclei in the extensive stratocumulus deck over the northern Benguela Upwelling System. Our findings also suggest that Southern African dust contains higher levels of K-feldspar than Northern African dust, and could therefore be an important source of ice-nucleating particles for low mixed-phase clouds over the Southern Ocean.

Traditional cookstoves in developing regions exhibit low thermal efficiency and elevated emissions, contributing to environmental and health concerns. This study experimentally investigates an enhanced cross-draft semicontinuous cookstove within the South African context. The stove incorporates a grate-shaking mechanism designed to prevent ash accumulation and maintain airflow during combustion. Four types of South African bituminous coal (A, B, C, and D) were evaluated under high and low-power operating conditions to assess thermal performance and emission characteristics. The results indicate that high-power conditions produced greater firepower and cooking power, whereas low-power operation yielded higher thermal efficiency for selected coal types. Type A exhibited the highest emissions of CO2, CO, and PM, while Type D showed comparatively lower emissions. SO2 and NOx emissions increased under high-power conditions, consistent with temperature-dependent sulphur and nitrogen reaction pathways. Notably, the overall PM emissions of 6.8-13.5 g/kg were substantially lower than values reported in the literature for comparable coal-based cookstoves. Temperature stratification between the hopper and combustion chamber influenced overall stove performance, with sustained thermal stability observed during semi-continuous operation. The grate-shaking mechanism was necessary to maintain combustion stability by mitigating ash accumulation and ensuring consistent airflow through the fuel bed. Compared to traditional cookstoves, the proposed design demonstrates reduced emissions and sustained combustion performance. These findings contribute to the advancement of cleaner coal combustion technologies and energy-efficient household cooking solutions in coal-dependent regions.

Mineral dust absorbs and scatters solar and infrared radiation, thereby affecting the radiance spectrum at the surface and top-of-atmosphere and the atmospheric heating rate. While half of the outgoing thermal radiation is emitted in the far infrared (FIR, 15-100 mu m), knowledge of the optical properties and thermal radiative effects of dust is currently limited to the mid-infrared region (MIR, 3-15 mu m). In this study we performed pellet spectroscopy measurements to evaluate the MIR and FIR contribution to dust absorbance and explore the variability and spectral diversity of the dust signature within the 2.5-25 mu m range. Thirteen dust samples re-suspended from parent soils with contrasting mineralogy were investigated, including low and mid latitude dust (LMLD) sources in Africa, America, Asia, and Middle East, and high latitude dust (HLD) from Iceland. Results show that the absorbance of dust in the FIR up to 25 mu m is comparable in intensity to that in the MIR. Also, spectrally different absorption (position and shape of the peaks) is observed for Icelandic dust compared to LMLD, due to differences in mineralogical composition. Corroborated with the few available literature data on absorption properties of natural dust and single minerals up to 100 mu m wavelength, these data suggest the relevance of MIR and FIR interactions to the dust radiative effect for low to high latitude sources. Furthermore, the dust spectral signatures in the MIR and FIR could potentially be used to characterise the mineralogy and differentiate the origin of airborne particles based on infrared remote sensing observations.

Southern Africa (SAf) is a key region for dust emissions, characterised by a wide variety of natural and anthropogenic sources, but also a critical knowledge gap in the mineral dust budget of the Southern Hemisphere. Projected climate warming is expected to lead to an increase in mineral dust emissions, which are increasingly linked to human activity. Although the transport and deposition pathways of SAf dust suggest that it can directly affect the regional climate and nearby marine ecosystems through dust-aerosol interaction and indirectly through aerosol-cloud/ice interaction and nutrient deposition, the extent of this impact is highly uncertain due to significant uncertainties in atmospheric loads and climate-relevant properties.This study provides the first comprehensive characterisation of the chemical and mineralogical composition of SAf dust aerosols. Aerosol samples were laboratory-generated using soils collected from key dust sources in southern Africa, including the Namib gravel plain, coastal ephemeral riverbeds, the Etosha salt pan, the Kalahari Desert, and anthropogenic sources such as agricultural soils from the Free State, savannah soils from the Kruger National Park, and a copper mine in Namibia.A geographical distribution of the chemical and mineralogical properties of SAf dust was identified based on the elemental ratios Si/Al, (Ca + Mg)/Al, and K/Al. This is influenced by both the regional geology and rainfall distribution, which shows an increase in the Si/Al ratio and a decrease in the (Ca + Mg)/Al and K/Al ratios, in areas with higher rainfall inland compared to the arid coast, while the salt pans exhibit unique features with significantly higher (Ca+Mg)/Al and Si/Al ratios.The SAf dust appears to be more enriched in Ca, Mg, and K than other dust sources in the Southern Hemisphere and northern African dust. Although Fe, a key micronutrient, occurs at similar levels in dust from both hemispheres, SAf dust contains more P, highlighting its potential significance in biogeochemical cycling. Despite limited mineralogical observations in the Southern Hemisphere, our results indicate that SAf dust contains more feldspar minerals than northern African dust, and may strongly influence the load of ice-nucleating particles over the Southern Ocean and, in turn, the regional radiative budget.

This study investigated the chemical composition and shortwave absorption coefficient, β abs ( λ ), of aerosols collected from sites on the Highveld, a major industrial and highly polluted region of South Africa. Local anthropogenic mineral dust was found to be the dominant chemical component, accounting for (53 ± 14)% of the aerosol mass concentrations. Carbonaceous aerosols (34 ± 12)%, mainly from domestic and waste biomass burning, and secondary inorganic aerosols (13 ± 6%) from anthropogenic combustion sources were also found. High β abs ( λ ) was observed at all sites, with an estimated mass absorption efficiency, MAE( λ ), from (1,296 ± 472) 10 −3 m 2 g −1 at 375 nm to (621 ± 239)10 −3 m 2 g −1 at 850 nm. The contributions of the primary light‐absorbing aerosols to β abs ( λ ) were determined using chemical tracers for two optical clusters identified based on the estimated MAE for black carbon (BC). BC was the major contributor to β abs ( λ ) at all wavelengths (>60%). The brown carbon contribution decreased with λ from (8–40) % at 375 nm to (1–23) % at 532 nm, and was higher in Cluster 1 than Cluster 2. Anthropogenic mineral dust in Cluster 2 appeared to be more light absorbing than pure desert dust and was a significant contributor to β abs ( λ ), constant with wavelength at ∼16%. The levels of light‐absorbing aerosols identified have implications for the radiation budget and atmospheric stability. Although BC dominates light absorption on the South African Highveld, mineral dust contributes significantly to aerosol mass concentrations and enhanced light‐absorption.

Drought is among the most pressing natural disasters of the 21st century. The need for insights to support local decision-making in planning and mitigation is critical. The Northern Cape Province of South Africa is highly drought-prone, yet its historical and projected drought patterns are not well understood. Therefore, this study assessed past (1962-2022), near-future (2023-2050), and far-future (2051-2100) drought dynamics across its five district municipalities-Frances Baard, John Taolo Gaetsewe, Namakwa, Pixley Ka Seme, and ZF Mgcawu-using CRU data and CORDEX-Africa RCM simulations based on CMIP6. Drought characteristics were analyzed using the Standardized Precipitation-Evapotranspiration Index (SPEI) at 6-, 12-, and 24-month timescales. Results revealed significant spatial and temporal variability. Frances Baard and John Taolo Gaetsewe experienced the most frequent short-term droughts, with far-future projections indicating a significant intensification of drought events (up to 8.2 events/decade for the 6-month SPEI). Namakwa and Pixley Ka Seme recorded the longest multi-year droughts historically (up to 78 months for the 24-month SPEI), with far-future projections showing continued severity for long-term droughts. Mann-Kendall trend analysis indicated significant upward trends in drought frequency and duration in Frances Baard and John Taolo Gaetsewe, while Namakwa showed mixed trends-a near-future decline followed by far-future intensification.

Health impacts associated with exposure to atmospheric aerosols are of global concern and are not completely understood. In addition, health studies are, especially, complicated in developing countries such as South Africa. Oxidative potential (OP), defined as a measure of the capacity of aerosols to oxidise target molecules, has been proposed as a viable alternative relevant biological metric to better quantify toxicological responses related to atmospheric aerosol exposure in health studies. The dithiothreitol (DTT) assay is the most commonly used method to determine OP of aerosols, which was used in this study to quantify the OP of outdoor and indoor atmospheric particulates collected at three low-income settlements in South Africa. This technique is easy-to-operate, low-cost, effective and reproducible. The DTT methodology had to be modified according to previous applications, which required choosing a suitable extraction procedure and -setup. The redox activity of size-resolved sampled aerosols was evaluated and related to their chemical composition with correlation analysis. The seasonal variations of DTT redox activity were established by normalizing in terms of aerosol mass and sampled volume for indoor and outdoor particulate samples. Higher redox activity was determined for the smallest aerosols (aerodynamic diameter

Background:Data on allergic rhinitis and respiratory health metrics are limited for South Africa, with grass pollen as a key outdoor aeroallergen. Exotic trees such as plane trees and ragweed produce highly allergenic pollen, dominating indigenous trees and weeds. Pollen allergy prevalence data is lacking in cities of North-West province such as Potchefstroom. Objectives:This study aimed to (i) assess the prevalence of allergies to major aeroallergens, including Poaceae (grasses), Cupressus/Hesperocyparis (cypresses), Platanus (plane tree), Ulmus (elm), Quercus (oak), Betula (birch), Olea (olive), Artemisia (sagebrush), Amaranthus (amaranth), Plantago (plantain), Morus (mulberry), and Ambrosia (ragweed), along with fungal spores such as Alternaria, Cladosporium, and Penicillium/Aspergillus, and (ii) investigate the monthly incidence of major aeroallergens and reactivity levels in sensitized adults in Potchefstroom. Methods:Skin prick tests (SPTs) were performed on 202 adults aged 18-64 years with confirmed allergic symptoms during a field campaign at North-West University (NWU)'s Potchefstroom campus. A test panel of grass, weed, tree, and fungal spore extracts previously identified via aerobiological monitoring was used. Symptom scores were recorded using ISAAC questionnaires; Spearman's statistical correlation between symptom frequency and monthly aeroallergen concentrations were analyzed. Results:Among the participants, 184 (91%) exhibited positive SPT reactions: 104 (57%) are monosensitized to pollen, 45 (24%) to fungal spores, and 35 (19%) are polysensitized. Aeroallergen prevalence was higher in females (73%) than in males (27%). The most common pollen allergens were Cynodon dactylon (Bermuda grass) (85%), Zea mays (maize) (46%), Platanus spp. (plane tree) (35%), and Ulmus campestris (field elm) (33%). Among fungal spores, Alternaria was the most common (93%), followed by Cladosporium (27%). A significant and positive statistical correlation was found between allergic rhinitis symptoms and monthly pollen concentrations of Betula, Morus, Platanus, and Quercus. Discussion & Conclusion:This pilot study linked aeroallergens detected in Potchefstroom with allergy profiles of local residents. The findings highlight the need for more comprehensive regional studies that integrate allergen testing with aerobiological data. Raising awareness and implementing health strategies are essential for managing allergic rhinitis in South Africa. More affordable and available SPTs kits, adapted to allergy prevalence in South Africa, are strongly suggested.

South Africa, with its industrialised economy, faces unique air pollution challenges. Our study investigates aerosol composition and absorption in the Highveld region. Understanding aerosol absorption is critical as it affects climate, air quality, and public health. Aerosol absorption in the lower atmosphere affects the evolution of the boundary layer and the dispersion of pollutants, which in turn affects air quality and public health. Aerosol filter samples (PM10 fractions) were collected from residential, traffic, and industrial sites during the dry season. Chemical analyses, including X-ray fluorescence, thermo-optical analysis, and ion chromatography, were carried out to determine elemental species, carbonaceous species, and water-soluble ions, respectively. Based on this, a mass closure calculation was performed to define the contribution of five major aerosol components. The calculated aerosol mass concentrations were in good agreement with the measurements (Normalised Mean Bias, NMB < 7%). No significant variation in PM10 concentration was observed between site types. Mineral dust appeared to be the main contributor to PM10, varying from about 48%-60% at different sites, followed by organic matter (OM, 22%-35%), secondary inorganic aerosols (SIA, 9%-12%), elemental carbon (EC, 4%-7%), and sea salt (ss, 1%-2%). Aerosol spectral absorption was obtained from multi-wavelength absorbance analysis (MWAA) measurements at 375, 407, 532, 635, and 850 nm. High absorption was measured in the following order: industrial> residential> traffic sites. The estimated absorption Ångström exponent (AAE) varied from 0.8 to 2 at different sites, indicating the contribution of several sources. At 850 nm absorption correlates well with EC as expected (r = 0.85). The obtained mass absorption efficiency (8 m2/g) is in line with expectations. Specific tracers were used to determine the contribution of the main absorbing aerosol components - black carbon (BC), brown organic carbon (BrC) from incomplete biomass combustion, and mineral dust - using correlations between estimated mass and measured absorption. Preliminary results indicate that although BC is the major contributor to absorption, accounting for 30%-60% absorption at 375 nm, followed by BrC 10%-50%, the contribution of the less absorbing but more abundant mineral dust is not negligible and can range from 2% to 50% in different samples. These results underline the complexity of aerosols in the region and their high absorption properties, and the need for a comprehensive understanding of its various components to accurately assess its impact.

Most major field campaigns, such as the Southern Africa Fire Atmosphere Research Initiative (SAFARI-92 and SAFARI-2000) and AErosol, RadiatiOn and CLOuds in southern Africa (AEROCLO-sA), have focused on the west coast of southern Africa, leaving the east coast underexplored. To address this, the Biomass Burning Aerosol Campaign (BiBAC) was initiated by the IRP ARSAIO (International Research Project – Atmospheric Research in Southern Africa and Indian Ocean) during the 2022 biomass burning season to study aerosol optical properties over southern Africa and the southwestern Indian Ocean (SWIO). This study analyzes aerosol properties during the intensive observation period (IOP) of BiBAC at Skukuza in Kruger National Park during two events: 18–23 September (Event 1) and 9–17 October (Event 2). Sun-photometer data, consistent with CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization), revealed a predominance of biomass burning aerosols. Transport analyses show southeastward movement of carbon monoxide (CO) and aerosols, reaching up to 6 km during Event 1 and 10 km during Event 2. Synoptic conditions, including frontal systems and baroclinic waves, drove regional and intercontinental pollutant transport, impacting the Mozambique Channel and surrounding areas. A “river of smoke” observed in Event 1 suggests novel synoptic conditions compared to previous studies. This study is the first to highlight two distinct transport mechanisms of aerosol plumes and CO from southern Africa and South America toward the SWIO basin, underscoring the significance of east-coast observations in understanding regional and global atmospheric dynamics.

This pioneering study evaluates the prevalence of aeroallergens reactivity among atopic populations living in the Vaal Triangle Airshed Priority Area (VTAPA), South Africa. A total of 138 volunteers (51 males and 87 females), of African, colored, white, and Asian ethnicity, and with a mean (range) age of 22 (18-56) years were participating in the study. The study was conducted on the North-West University (NWU) campus in Vanderbijlpark/VTAPA. The International Study of Asthma and Allergies in Childhood questionnaire was utilized for pre-screening to identify individuals with probable allergic dispositions. Subsequently, skin prick testing was conducted using commercial aeroallergen extracts for all confirmed participants with allergy symptoms. One hundred six participants were clinically diagnosed with pollen and fungal spore allergies. The highest allergy prevalence was attributed to Cynodon dactylon ((L.) Pers) (Bermuda grass) (41.5%), followed by Lolium perenne (L.) (ryegrass), grass mix, and Zea mays (L.) (maize) (31.1%), respectively. Moreover, among the tree allergens, Olea (L.) (olive tree) was the most prevalent allergen (20; 18.8%), followed by Platanus (L.) (plane tree) (18; 16.9%). Among the weeds, 16 (15.1%) participants were allergic to the weed mix (Artemisia (L.) (wormwood), Chenopodium (Link) (goosefoot), Salsola (L.) (saltwort), Plantago (L.) (plantain), and 11 (10.3%) to Ambrosia (L.) (ragweed)). Regarding the fungal spores, Alternaria (Fr.) (9; 8.5%) followed by Cladosporium (Link) (5; 4.7%) had the highest skin sensitivity. In this pilot study, our findings provide insights into the prevalence of allergic responses in the study population-underlining the strong impact of allergens of exotic plants-and contribute to the existing aerobiological data in South Africa.

The western coast of southern Africa is a region of particular climate interest and crossroads for aerosols of different origins as well as fog occurrences. In this study, we present a comparison between the concentration of dissolved trace metals in pairs of total suspended particulate (TSP) and fog water samples collected in Henties Bay, Namibia, during the AErosols, Radiation and CLOuds in southern Africa (AEROCLO-sA) field campaign in September 2017. From inductively coupled plasma mass spectrometry measurements, we found that the concentration of dissolved Al, Fe, Ni, Cu, and Cr is enhanced in fog samples compared to the TSP samples. We found that thermodynamic modelling predicts the formation of soluble complexes with inorganic and organic ligands in fog for Cu, Cr, and Ni, but it would predict Al and Fe to precipitate as hydroxides given the neutral pH of fog. In contrast, X-ray absorption near edge structure measurements showed the presence of oxalate of Fe complexes that could explain its enhanced dissolved concentration in fog samples, despite a neutral pH. In addition, transmission electron microscopy and dynamic light scattering measurements revealed the presence of nano-sized colloidal particles containing Fe and Al in filtered fog samples that may appear soluble in inductively coupled plasma mass spectrometer (ICP-MS) measurements. We hypothesise that these complexes are formed in the early stages of particle activation into droplets when water content and, therefore, pH are expected to be lower and then remain in fog in a kinetically stable form or lead to the formation of colloidal nanoparticles.

This research used descriptive statistics to analyse rainfall trends in the Cuvelai- Etosha Basin (Namibia) over a 50-year historical period (1968 to 2018). The results revealed that rainfall fell over a period of 6 months between the months of November and April. Rainfall amounts were also observed to be higher in the first 3 months of each year, and annual levels ranged between 200 mm and 700 mm. The trend revealed that rainfall levels between 1977 and 1992 were consistently below the calculated average of 410 mm, and the rainfall amounts, and rain season were observed to have significantly shortened between the years 2009 and 2018. The rainfall trend observed over the 50-year period did not provide a definitive indication of whether the pattern followed a specific trajectory. The trend line’s position was below the average line for many seasons, and it indicated that many of the seasons experienced rainfall levels below the annual average; however, an increase was observed from the years 2008 -2012 and the year 2018 wherein the rainfall received was above average and fell intensely over a brief period and these are the years where flooding was reported. Contribution: An epileptic pattern was observed that could not be used to definitively define a trend but was useful to highlight that there was an occurrence of episodes of heavy rainfall being experienced in the months of January through March and any resilience efforts need to be prioritised during this time.

Mercury (Hg) is a pollutant that adversely affects all regions worldwide. This study investigates how Gaseous Elemental Mercury (GEM), the predominant form of Hg, has changed over the Southern African Highveld Priority Area (SAHPA) since 2009. The SAHPA is one of the regions of interest regarding South African air quality, given its frequent and recurrent occurrence of pollutant concentrations exceeding the country's prescribed thresholds. The present study measured GEM concentrations and other South African criteria pollutants and meteorological parameters between 2016 and 2023 at Elandsfontein, an industrially/anthropogenically influenced monitoring site on the SAHPA. Following quality control procedures, major jumps and shifts were noticed in some of the data for 2016 and 2019, as well as all of the 2017 and 2018 data, these data were excluded from the analysis. The mean hourly GEM concentrations during the monitoring period at Elandsfontein ranged from 0.10 to 71.22 ng/m(3) with a mean concentration of 1.74 +/- 1.62 ng/m(3). The observed mean GEM concentrations exhibit characteristic seasonal patterns, with the highest levels in winter (1.94 +/- 2.00 ng/m(3)), spring (1.83 +/- 1.85 ng/m(3)), autumn (1.79 +/- 1.1.55 ng/m(3)), and summer (1.48 +/- 1.08 ng/m(3)). The diurnal variation of GEM at Elandsfontein shows a distinct pattern, with concentrations peaking before sunrise and dipping in the late afternoon. High GEM concentrations (>6 ng/m(3)) are linked to air masses from the western interior, indicating significant local emissions. Pollution events peak between July and October 2016-2023, likely due to increased domestic fuel combustion and biomass burning during the dry season, contributing to elevated atmospheric pollutant levels. An Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) analysis showed that eastern air masses were predominantly 'clean' and ocean-derived, emphasising the significant influence of local and regional emissions of GEM surrounding the site. These findings highlight the complex interaction of meteorology and pollutant emissions in shaping GEM levels. Further research is needed to understand better how GEM variations are influenced by interactions with other pollutants, meteorology, halogens, and ozone, particularly in the southern hemisphere.

Landfill gas (LFG) emissions, primarily CH4 and CO2, result from decomposing organic waste in landfills. South Africa faces challenges in managing LFG emissions and effectively handling landfill sites. For this study, a static flux chamber was used to sample CH4 and CO2 emissions. The study showed that CH4 emissions in the capped area had a concentration of 360 819.80 mg m-3, with an average emission rate of 433.00 g per m2 per day, resulting in 6363.43 Mg per year during the wet season. The active area was observed to have emitted the highest CH4 concentration (419 863 mg m-3) when compared to other areas of the landfill. The lowest CH4 concentration (45 922.52 mg m-3) was emitted from the virgin area. From the virgin area, an average emission rate of 55.11 g per m2 per day, resulting in 605.72 Mg per year, was recorded. Similar results based on the sample area variations were also observed during the dry season. Specifically, the active and capped sample area experienced higher CH4 emissions than the leachate and virgin sample areas. Furthermore, it was observed that the concentrations and emission rates of LFGs emitted during the dry season were lower when compared to the wet season. Similarly, the concentration of CO2 emissions was higher during the wet season than during the dry season. Enhanced control methods are recommended to improve LFG management practices, especially during the wet season when emissions are higher. Highlighting seasonal variability in emissions underscores the need for targeted strategies to mitigate environmental and health risks. Quantifying LFG emissions from the Thohoyandou landfill in this study sheds light on the environmental and health risks involved. The data presented are crucial for improving landfill management practices in South Africa and for validating the LandGEM model with field-measured and laboratory-analyzed data.

Growing concerns over energy usage are revitalizing interest in applying thermal remote sensing technologies to obtain information that can support decision-makers in developing strategies that reduce energy consumption and CO2 emissions within residential environments. The purpose of this study was to evaluate the feasibility of aerial thermography as a tool for in-situ determination of the thermal insulation quality of residential dwellings in South Africa. Utilizing high-resolution orthomosaic airborne thermal infrared imaging, the study surveyed selected residential dwellings across the KwaZamokuhle settlement in Mpumalanga Province. The study findings were that the use of aerial thermal infrared imaging can differentiate residential dwelling quality, thus identifying poorly insulated homes, which are often linked to higher energy consumption and increased carbon emissions. The results suggest that high-resolution aerial thermal infrared imagery has considerable potential as a tool to evaluate the thermal insulation status of residential dwellings, especially in large settlements where rapid assessments might be needed. The approach holds a lot of potential in supporting energy efficiency interventions and informing policy development towards improving residential dwellings' energy efficiency in South Africa and other low-income countries that face housing quality challenges.