Ambient and indoor temperature affects thermal comfort and human health. In a changing climate with a predicted change in temperature extremes, understanding indoor temperatures, both hot and cold, of different housing types is important. This study aimed to assess the hourly, daily and monthly variation in indoor temperatures in different housing types, namely formal houses, informal houses, flats, government-built low-cost houses and old, apartheid era low-cost housing, in five impoverished urban communities in Johannesburg, South Africa. During the cross-sectional survey of the Health, Environment and Development study data loggers were installed in 100 homes (20 per suburb) from February to May 2014. Indoor temperature and relative humidity were recorded on an hourly basis. Ambient outdoor temperatures were obtained from the nearest weather station. Indoor and outdoor temperature and relative humidity levels were compared; and an inter-comparison between the different housing types were also made. Apparent temperature was calculated to assess indoor thermal comfort. Data from 59 retrieved loggers showed a significant difference in monthly mean indoor temperature between the five different housing types (p < 0.0001). Low cost government-built houses and informal settlement houses had the greatest variation in temperature and experienced temperatures between 4 and 5 °C warmer than outdoor temperatures. Housing types occupied by poor communities experienced indoor temperature fluctuations often greater than that observed for ambient temperatures. Families living in government-built low-cost and informally-constructed homes are the most at risk for indoor temperature extremes. These types of housing should be prioritised for interventions aimed at assisting families to cope with extreme temperatures, gaining optimal thermal comfort and preventing temperature-related health effects.

Climate change impacts on working people (the HOTHAPS initiative): findings of the South African pilot study

Diarrhoeal disease is a significant contributor to child morbidity and mortality, particularly in the developing world. Poor sanitation, a lack of personal hygiene and inadequate water supplies are known risk factors for diarrhoeal disease. Since risk factors may vary by population or setting, we evaluated the prevalence of diarrhoeal disease at the household level using a questionnaire to better understand household-level risk factors for diarrhoea in selected rural areas in South Africa. In a sub-sample of dwellings, we measured the microbial quality of drinking water. One in five households had at least one case of diarrhoea during the previous summer. The most widespread source of drinking water was a stand-pipe (inside yard) (45%) followed by an indoor tap inside the dwelling (29%). Storage of water was common (97%) with around half of households storing water in plastic containers with an opening large enough to fit a hand through. After adjusting for confounders, the occurrence of diarrhoea was statistically significantly associated with sourcing water from an indoor tap (Adjusted Odds Ratio (AOR): 2.73, 95% CI: 2.73, 1.14–6.56) and storing cooked/perishable food in non-refrigerated conditions (AOR: 2.17, 95% CI: 2.17, 1.44–3.26). The highest total coliform counts were found in water samples from kitchen containers followed by stand-pipes. Escherichia coli were most often detected in samples from stand-pipes and kitchen containers. One in four households were at risk of exposure to contaminated drinking water, increasing the susceptibility of the study participants to episodes of diarrhoea. It is imperative that water quality meets guideline values and routine monitoring of quality of drinking water is done to minimise diarrhoea risk in relevant rural communities. The security of water supply in rural areas should be addressed as a matter of public health urgency to avoid the need for water storage.

A cross-sectional analytical study of geophagia practices and blood metal concentrations in pregnant women in Johannesburg, South Africa