Objective To assess whether exposure to high temperatures in pregnancy is associated with increased risk for preterm birth, low birth weight, and stillbirth. Design Systematic review and random effects meta-analysis. Data sources Medline and Web of Science searched up to September 2018, updated in August 2019. Eligibility criteria for selecting studies Clinical studies on associations between high environmental temperatures, and preterm birth, birth weight, and stillbirths. Results 14 880 records and 175 full text articles were screened. 70 studies were included, set in 27 countries, seven of which were countries with low or middle income. In 40 of 47 studies, preterm births were more common at higher than lower temperatures. Exposures were classified as heatwaves, 1°C increments, and temperature threshold cutoff points. In random effects meta-analysis, odds of a preterm birth rose 1.05-fold (95% confidence interval 1.03 to 1.07) per 1°C increase in temperature and 1.16-fold (1.10 to 1.23) during heatwaves. Higher temperature was associated with reduced birth weight in 18 of 28 studies, with considerable statistical heterogeneity. Eight studies on stillbirths all showed associations between temperature and stillbirth, with stillbirths increasing 1.05-fold (1.01 to 1.08) per 1°C rise in temperature. Associations between temperature and outcomes were largest among women in lower socioeconomic groups and at age extremes. The multiple temperature metrics and lag analyses limited comparison between studies and settings. Conclusions Although summary effect sizes are relatively small, heat exposures are common and the outcomes are important determinants of population health. Linkages between socioeconomic status and study outcomes suggest that risks might be largest in low and middle income countries. Temperature rises with global warming could have major implications for child health. Systematic review registration PROSPERO CRD 42019140136 and CRD 42018118113.

Links between heat exposure and congenital anomalies have not been explored in detail despite animal data and other strands of evidence that indicate such links are likely. We reviewed articles on heat and congenital anomalies from PubMed and Web of Science, screening 14,880 titles and abstracts in duplicate for articles on environmental heat exposure during pregnancy and congenital anomalies. Thirteen studies were included. Most studies were in North America (8) or the Middle East (3). Methodological diversity was considerable, including in temperature measurement, gestational windows of exposure, and range of defects studied. Associations were detected between heat exposure and congenital cardiac anomalies in three of six studies, with point estimates highest for atrial septal defects. Two studies with null findings used self-reported temperature exposures. Hypospadias, congenital cataracts, renal agenesis/hypoplasia, spina bifida, and craniofacial defects were also linked with heat exposure. Effects generally increased with duration and intensity of heat exposure. However, some neural tube defects, gastroschisis, anopthalmia/microphthalmia and congenital hypothyroidism were less frequent at higher temperatures. While findings are heterogenous, the evidence raises important concerns about heat exposure and birth defects. Some heterogeneity may be explained by biases in reproductive epidemiology. Pooled analyses of heat impacts using registers of congenital anomalies are a high priority.

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The household combustion of solid fuels, for the purpose of heating and cooking, is an activity practiced by many people in South Africa. Air pollution caused by the combustion of solid fuels in households has a significant influence on public health. People most affected are those considered to be the poorest, living in low-income settlements, where burning solid fuel is the primary source of energy. Insufficient data has been collected in South Africa to quantify the concentrations of particulate emissions that people are exposed to, especially the respirable fraction, associated with the combustion of solid fuels. The aim of this paper is to gain an understanding of the particulate matter (PM) concentrations a person living in a typical household in a low income settlement in the South African Highveld is exposed to. It also seeks to demonstrate that the use of solid fuels in the household can lead to indoor air pollution concentrations reaching levels very similar to ambient PM concentrations, which could be well in excess of the National Ambient Air Quality Standards, representing a major national public health threat. A mobile monitoring station was used in KwaDela, Mpumalanga to measure both ambient particulate concentrations and meteorological conditions, while a range of dust/particulate monitors were used for indoor and personal particulate concentration measurements. Indoor and personal measurements are limited to the respirable fraction (PM 4 ) as this fraction contributes significantly to the negative health impacts. The sampling for this case study took place from 7-19 August 2014. Highest particulate matter concentrations were evident during the early mornings and the early evenings, when solid fuel burning activities were at their highest. Indoor and personal daily average PM 4 concentrations did not exceed the 24h National Ambient PM 2.5 Standard of 65 µg/m 3 nor did they exceed the 24h National Ambient PM 10 Standard of 75 µg/ m 3 . The outdoor PM 2.5 concentrations were found to be below the standards for the duration of the sampling period. The outdoor PM 10 concentrations exceeded the standards for one day during the sampling period. Results indicate that, although people in KwaDela may be exposed to ambient PM concentrations that can be non-compliant to ambient standards, the exposure to indoor air, where solid fuel is burnt, may be detrimental to their health. Keywords particulate matter exposure, indoor air quality, ambient air quality, personal exposure

In low-income communities, non-electric fuel sources are typically the main cause of Household Air Pollution (HAP). In Umlazi, a South African coastal, informal settlement, households use electric- and non-electric (coal, wood, gas, paraffin) energy sources for cooking and heating. The study aimed to determine whether respiratory ill health status varied by fuel type use. Using a questionnaire, respondents reported on a range of socio-demographic characteristics, dwelling type, energy use for cooking and heating as well as respiratory health symptoms. Multivariate Poisson regression was used to obtain the adjusted Odds Ratios (ORs) for the effects of electric and non-electric energy sources on prevalence of respiratory infections considering potential confounding factors. Among the 245 households that participated, Upper Respiratory Tract Infections (URTI, n = 27) were prevalent in respondents who used non-electric sources compared to electric sources for heating and cooking. There were statistically significant effects of non-electric sources for heating (adjusted OR = 3.6, 95% CI (confidence interval): 1.2–10.1, p < 0.05) and cooking (adjusted OR = 2.9, 95% CI: 1.1–7.9, p < 0.05) on prevalence of URTIs. There was a statistically significant effect of electric sources for heating (adjusted OR = 2.7, 95% CI: 1.1–6.4, p < 0.05) on prevalence of Lower Respiratory Tract Infections (LRTIs) but no evidence for relations between non-electric sources for heating and LRTIs, and electric or non-electric fuel use type for cooking and LRTIs. Energy switching, mixing or stacking could be common in these households that likely made use of multiple energy sources during a typical month depending on access to and availability of electricity, funds to pay for the energy source as well as other socio-economic or cultural factors. The importance of behaviour and social determinants of health in relation to HAP is emphasized.

Residential solid fuel combustion emission within low-income communities result in increased negative health impacts within these settlements. The Highveld is considered to be the industrial epicentre of South Africa as it houses 11 of the 13 coal-fired power stations situated within the country's borders. The availability of low-cost coal within the area makes it the fuel of choice for heating and cooking purposes within low-income settlements. As a result residents of these settlements are continuously exposed to high concentrations of air pollutants. A paucity in data, on the impact of residential solid fuel combustion, exists since research is mainly focussed on industrial emission impacts. This paper aims to accurately quantify and characterise the mass concentrations of particulate matter experienced within both the indoor (PM4) and ambient (PM 10 , PM 2.5 ) environments of KwaDela, a low-income settlement located on the South African Highveld. Furthermore, an attempt was made to link the indoor and ambient particulate mass concentrations, identify diurnal patterns and seasonal variations. KwaDela experiences high levels of particulate pollution, within both the indoor and ambient environment, as a result of domestic solid fuel combustion. Energy use varies seasonally with higher consumption of solid fuels during the winter leading to increased particulate loading. The concentrations of respirable particulate concentrations within the indoor environment are significantly higher than PM10 and PM 2.5 experienced in the ambient environment. This indicates that the effect of respirable particulate matter, associated with solid fuel combustion in the indoor environment, has been underrepresented and thus its effect on health underreported.

Climate change is associated with shifts in global weather patterns, especially an increase in ambient temperature, and is deemed a formidable threat to human health. Skin cancer, a non-communicable disease, has been underexplored in relation to a changing climate. Exposure to solar ultraviolet radiation (UVR) is the major environmental risk factor for skin cancer. South Africa is situated in the mid-latitudes and experiences relatively high levels of sun exposure with summertime UV Index values greater than 10. The incidence of skin cancer in the population group with fair skin is considered high, with cost implications relating to diagnosis and treatment. Here, the relationship between skin cancer and several environmental factors likely to be affected by climate change in South Africa are discussed including airborne pollutants, solar UVR, ambient temperature and rainfall. Recommended strategies for personal sun protection, such as shade, clothing, sunglasses and sunscreen, may change as human behaviour adapts to a warming climate. Further research and data are required to assess any future impact of climate change on the incidence of skin cancer in 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.