Socio-economic, infrastructural and health-related risk factors associated with adverse heat-health effects reportedly experienced during hot weather in South Africa

Our plain-English summary of Socio-economic, infrastructural and health-related risk factors associated with adverse heat-health effects reportedly experienced during hot weather in South Africa, by C.Y. Wright, F. Dominick, T. Kapwata, et al (The Pan African Medical Journal, 2019).

The study

• Authors: C.Y. Wright, F. Dominick, T. Kapwata, S. Bidassey-Manilal, J.C. Engelbrecht, H. Stich, A. Mathee, M. Matooane
• Journal: The Pan African Medical Journal
• Published: 2019;34:40
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Poor urban communities are likely to bear the brunt of climate change impacts on health and well-being. The City of Johannesburg, South Africa, is predicted to experience an average increase in ambient temperature of 4°C by 2100. Focusing on the urban environment, this study aimed to determine socio-economic, infrastructural and health-related risk factors for heat-related adverse health effects.

Methods: This was a cross-sectional study. Data of interest were collected using a pretested and validated questionnaire administered to parents of children attending schools participating in a school heat study. Information related to demographic, socio-economic and household-level determinants of health, which has an impact on the individual prevalence of adverse heat-health effects associated with hot weather, was collected for 136 households and 580 individuals.

Results: Sweating (n = 208 individuals; 35%), headache and nausea (n = 111; 19%) and weakness, fatigue and dizziness (n = 87; 15%) were the most common heat-health effects reportedly experienced by individuals (n = 580) during hot weather. Individuals who suffered from hypertension (OR = 2.32, 95% CI: 1.34 - 4.05, p = 0.003) and individuals older than 60 years (OR = 1.81, 95% CI: 1.27-1.99, p < 0.001) compared to other age groups were more likely to experience 'any heat-health effects'. Living in government-sponsored detached housing and in houses with asbestos roofs were associated with an increase in reported experience of 'any heat-health effects' compared to living in other housing types.

Conclusion: Heat-health awareness campaigns should target people suffering from pre-existing diseases and the elderly, as these groups are especially vulnerable to heat. Focus should also be given to appropriate roofing and insulation in government-sponsored housing since summertime temperatures are projected to increase.

© Caradee Yael Wright et al.

In plain English

This cross-sectional study in Johannesburg, South Africa, looked at health effects people reported during hot weather. Asbestos appeared only as one roofing material, and asbestos-related disease was not studied. In early 2014, parents of schoolchildren taking part in a classroom-heat study filled in questionnaires, and 136 households covering 580 people were analysed. The most often reported effects were sweating (208 people), headache and nausea (111), and weakness, fatigue and dizziness (87). People over 60 (odds ratio 1.81, 95% CI 1.27 to 1.99) and people with hypertension (odds ratio 2.32, 95% CI 1.34 to 4.05) were more likely to report any heat-health effect. Living in a government-sponsored RDP house was linked to more reported effects than living in a single detached house (odds ratio 2.01, 95% CI 1.15 to 3.52). Asbestos-sheet roofs had the highest odds among roof types compared with tiled roofs (odds ratio 1.04, 95% CI 0.61 to 1.77), but this was not statistically significant. The authors concluded that older people and people with pre-existing diseases, especially hypertension, should be targeted for heat-health information. They noted a small sample and wide confidence intervals.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional questionnaire study using bivariate logistic regression (crude odds ratios)
• Who was studied: Households of parents or caregivers of children at schools in a classroom-heat study in the City of Johannesburg. Questionnaires were distributed between 1 February and 31 March 2014. Of 480 distributed, 217 were returned (45%), and 136 households with 580 individuals met the inclusion criteria.
• Exposure: Hot weather, with socio-economic, health-related and dwelling risk factors examined. These included age, sex, doctor-diagnosed chronic conditions, housing type and roof type. Roof types were tiles (reference), thatch, asphalt shingles, asbestos sheets (76 individuals, 13.1%) and corrugated iron sheets. No asbestos fiber type or asbestos exposure measurement is reported.
• Main results:
  • Of the 580 individuals, the most commonly reported heat-health effects were sweating (208), headache and nausea (111), and weakness, fatigue and dizziness (87).
  • Individuals older than 60 years were more likely to report 'any heat-health effects' than individuals in other age groups: OR 1.81, 95% CI 1.27 to 1.99, p less than 0.001.
  • Individuals with hypertension were more likely to report 'any heat-health effects': OR 2.32, 95% CI 1.34 to 4.05, p = 0.003. Hypertension was the only chronic condition with a statistically significant association.
  • Females were 1.15 times more likely than males to report 'any heat-health effects', but this was not statistically significant (OR 1.15, 95% CI 0.82 to 1.62, p = 0.412).
  • Living in a government-sponsored (RDP-type) house was associated with more reported heat-health effects than living in a single detached house (reference): crude OR 2.01, 95% CI 1.15 to 3.52, p = 0.01 (Table 3).
  • Individuals in dwellings with asbestos-sheet roofs (76 individuals) had the highest odds among roof types of reporting heat-health effects, compared with tiled roofs. This was not statistically significant: crude OR 1.04, 95% CI 0.61 to 1.77, p = 0.89 (Table 3).
• The authors' conclusion: The authors concluded that people with pre-existing diseases, especially hypertension, and the elderly should be targeted for heat-health information on coping during hot weather.
• Limitations the authors state:
  • The sample came from another study, and one parent or caregiver reported the housing, demographic and health information for every household member.
  • The authors assumed caregivers understood the terminology used for heat-health effects and chronic health outcomes.
  • Not all potential confounders were collected, and the severity of heat-health effects was not recorded.
  • Temperatures inside respondents' houses were not measured, and the hot weather referred to in the questionnaire was not specified.
  • The small sample and poor response led to low disease prevalence and wide confidence intervals. The authors said these risk factors should be tested in a larger sample.

Related studies

• Students' Perceived Heat-Health Symptoms Increased with Warmer Classroom Temperatures — S. Bidassey-Manilal, C.Y. Wright, et al. (2016)
• Asbestos-related disease in South Africa: the social production of an invisible epidemic — L. Braun, S. Kisting (2006)
• Factors influencing the reading of small irregular opacities in a radiological survey of asbestos miners in South Africa — G.K. Sluis-Cremer, P.A. Hessel, et al. (1989)
• Lung cancer, tobacco, and environmental factors in the African population of the Northern Province, South Africa — O. Mzileni, F. Sitas, et al. (1999)
• CT scan screening for lung cancer: risk factors for nodules and malignancy in a high-risk urban cohort — A.K. Greenberg, F. Lu, et al. (2012)
• Asbestos exposure during home renovation in New South Wales — E.K. Park, D.H. Yates, et al. (2013)

Browse return to medical research.