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

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.

Students' Perceived Heat-Health Symptoms Increased with Warmer Classroom Temperatures.

Temperatures in Africa are expected to increase by the end of the century. Heat-related health impacts and perceived health symptoms are potentially a problem, especially in public schools with limited resources. Students (n = 252) aged ~14-18 years from eight high schools completed an hourly heat-health symptom log over 5 days. Data loggers measured indoor classroom temperatures. A high proportion of students felt tired (97.2%), had low concentration (96.8%) and felt sleepy (94.1%) during at least one hour on any day. There were statistically significant correlations, when controlling for school cluster effect and time of day, between indoor temperatures ≥32 °C and students who felt tired and found it hard to breathe. Consistently higher indoor classroom temperatures were observed in classrooms constructed of prefabricated asbestos sheeting with corrugated iron roof and converted shipping container compared to brick classrooms. Longitudinal studies in multiple seasons and different classroom building types are needed.

Regional Projections of Extreme Apparent Temperature Days in Africa and the Related Potential Risk to Human Health.

Regional climate modelling was used to produce high resolution climate projections for Africa, under a "business as usual scenario", that were translated into potential health impacts utilizing a heat index that relates apparent temperature to health impacts. The continent is projected to see increases in the number of days when health may be adversely affected by increasing maximum apparent temperatures (AT) due to climate change. Additionally, climate projections indicate that the increases in AT results in a moving of days from the less severe to the more severe Symptom Bands. The analysis of the rate of increasing temperatures assisted in identifying areas, such as the East African highlands, where health may be at increasing risk due to both large increases in the absolute number of hot days, and due to the high rate of increase. The projections described here can be used by health stakeholders in Africa to assist in the development of appropriate public health interventions to mitigate the potential health impacts from climate change.

Health risk assessment for sulfur dioxide pollution in South Durban, South Africa.

Concern about health risks from sulfur dioxide (SO2) pollution prompted a health risk assessment for residents of the heavily polluted industrial region of South Durban, South Africa. The U.S. Environmental Protection Agency health risk assessment model was used to evaluate health effects for individuals in 4 age groups on the basis of data for a 3-yr period, from 1997-1999. Under normal exposure conditions, the level of risk was low (Hazard Quotient < 1); only under the worst-case scenario (exposure 24 hr/day) was there a significant risk of developing health effects. Inasmuch as these results are contrary to the popularly held belief that residents have a high risk of developing SO2-related respiratory diseases under normal exposure conditions, future studies should more thoroughly investigate exposure patterns and verify the authors' assumption that indoor SO2 levels are zero.