A Cross-Sectional, Randomized Cluster Sample Survey of Household Vulnerability to Extreme Heat among Slum Dwellers in Ahmedabad, India

Abstract

Extreme heat is a significant public health concern in India; extreme heat hazards are projected to increase in frequency and severity with climate change. Few of the factors driving population heat vulnerability are documented, though poverty is a presumed risk factor. To facilitate public health preparedness, an assessment of factors affecting vulnerability among slum dwellers was conducted in summer 2011 in Ahmedabad, Gujarat, India. Indicators of heat exposure, susceptibility to heat illness, and adaptive capacity, all of which feed into heat vulnerability, was assessed through a cross-sectional household survey using randomized multistage cluster sampling. Associations between heat-related morbidity and vulnerability factors were identified using multivariate logistic regression with generalized estimating equations to account for clustering effects. Age, preexisting medical conditions, work location, and access to health information and resources were associated with self-reported heat illness. Several of these variables were unique to this study. As sociodemographics, occupational heat exposure, and access to resources were shown to increase vulnerability, future interventions (e.g., health education) might target specific populations among Ahmedabad urban slum dwellers to reduce vulnerability to extreme heat. Surveillance and evaluations of future interventions may also be worthwhile.

Extreme heat in India and anthropogenic climate change

“…The humanitarian impact of these heat waves was large, with 40 % of all extreme-weather-related deaths attributed to heat waves in 2016, which is the largest proportion of total deaths of any type of extreme weather event (India Meteorological G. J. van Oldenborgh et al: Extreme heat in India and anthropogenic climate change Department, Climate Research and Services, 2017). Experience in implementing heat wave interventions has shown that these deaths can be greatly reduced by straightforward measures such as keeping parks and homeless shelters open on the hottest days and providing early warning of a forecasted heat wave (Fouillet et al, 2008;Tran et al, 2013).…”

“…This happened in Europe up to the mid-1980s (e.g. and there is evidence that this plays a role in India (Krishnan and Ramanathan, 2002;van Donkelaar et al, 2015;Padma Kumari et al, 2007;Wild et al, 2007). The third mechanism is an increase in irrigation (Ambika et al, 2016) that leads to higher moisture availability and hence increased evaporation, leaving less energy to heat the air.…”

“…Those directly exposed to the heat including outdoor workers, the homeless and those with pre-existing medical conditions (e.g. the elderly) constitute the majority of negative heat-related outcomes in India (Tran et al, 2013;Nag et al, 2009). Naturally, the question was raised whether human-induced climate change played a role in this record-breaking heat.…”

Heat Waves Research and Impacts on Human Health: The Need for Studies in Nigeria: A Review

“…Time series analysis was also employed to identify the serial correlations and trends over time, seasonal variations over time and the possibility of forecasting future dengue outbreaks. More importantly Trang et al [18], developed an autoregressive integrated moving average (ARIMA) model to predict future dengue outbreaks in a cross sectional randomized cluster sample survey [19] of districts in Sri Lanka using GIS as a tool to identify dengue risk associated with population density, land pattern and climatic factors. GIS was employed to design a dashboard for health authorities to survey high-risk areas for control.…”

Urban governance and the systems approaches to health-environment co-benefits in cities

“…On a micro scale, slums and informal settlements, generally occupied by the poor, face disproportionately greater risks related to climate change 25 and health 26 . They are often unplanned, lacking both the infrastructure and service base of wealthier neighborhoods.…”