The risk of extreme heat on child mortality is influenced by factors such as age, region and season, new study shows.
Research, led by members of the HIGH Horizons consortium, showed that the influence of extreme heat on the risk of death in children under five varies by age group, region and season.
The study, published in The Lancet Planetary Health, examined the effects of heat on child death rates across various regions in Africa, focusing on neonates (younger than 28 days), post-neonates (28 days to 1 year old) and children (1 to 5 years old).
Reducing child mortality by 2030 is a sustainable development goal, however many countries around the world are currently missing the target set by the UN. While research has previously shown a relationship between the leading causes of death in children, such as malaria and malnutrition, and climate change, there is little evidence exploring the effects of heat exposure in detail.
This study looked at the relationship between the leading causes of death in children and heat exposure. Researchers analysed health data that covered 29 settlements in 13 African countries, collected from 1993 to 2016. All child deaths, regardless of cause of death, were analysed against wet bulb globe temperature, an international standard for heat stress and the most widely used heat indicator.
The link between heat and death was evaluated against the different age groups as well as seasons, including all seasons, the dry season and monsoon season and, climatic region, which grouped regions of countries with similar climate patterns together.
The study found variation in child and neonatal death rates between regions and age. For example, in Ethiopia, extreme heat was associated with increased mortality risk among neonates but not among older children. In Eastern Africa, Senegal and The Gambia, there was a notable increase in mortality risk for children due to heat exposure across the full year.
Researchers suggest that previous studies examining leading causes of death that used combined health outcomes, such as deaths from across different seasons and climate zones, might overlook important details about the influence heat has also played in child death rates.
Dr Chloe Brimicombe, HIGH Horizons and Wegener Center for Climate and Global Change, University of Graz, said:
“Our study addresses the gap in evidence about the effects of heat exposure on child mortality in Africa, an area that is expected to be severely affected by extreme heat and climate change.
“We think that other cross-country studies may have previously missed nuances that this research has identified and moving forward, research and policy should focus on whether prevention measures for leading causes of death in children under five are also effectively reducing the impact of extreme heat on child death rates.”
As extreme heat events continue to increase, researchers suggest that without efforts to mitigate climate change, progress towards reducing child mortality could be delayed.
This research did not include the study of factors such as sex, maternal education and ethnicity and therefore it is suggested that social, economic and vulnerability factors should also be taken into account for future studies.
This research was funded by the European Union’s Horizons programme as part of the HIGH Horizons project under grant agreement number 101057843. LSHTM is funded by UKRI Innovate UK reference number 10038478. Professor Jackson is also funded by the Takeda Foundation.