Effects of climate and environmental factors on childhood and adolescent asthma: A systematic review based on spatial and temporal analysis evidence
Jian Wang, Javier Cortés-Ramírez, Thian Yew Gan, J M Davies, W. Hu
Abstract
Asthma is a prevalent chronic respiratory disease among children, influenced by various climate and environmental factors. Despite its prevalence, the specific effects of these factors on asthma remain unclear. This study aims to systematically assess the epidemiological evidence using spatial and temporal methods on the impact of climate and environmental factors on childhood asthma. A systematic review was conducted to analyse the impact of climate and environmental factors on childhood asthma and wheezing, focusing on spatial and temporal trends. Searches were carried out in PubMed, Embase, and CINAHL databases for studies published from January 2000 to April 2024, using key search terms ‘asthma/wheezing’, ‘extreme weather, ‘green space’, ‘air pollution’ and ‘spatial or temporal analyses”. The systematic review analysed 28 studies, with six employing spatial and 22 using temporal analysis methods; however, none incorporated spatio-temporal analysis in their models. The findings reveal that extreme weather events, including heatwaves and heavy rainfall, elevate childhood asthma risks across various climates, with significant effects observed during summer and winter months. Dust storms in arid and subtropical regions are linked to immediate spikes in hospital admissions due to asthma exacerbations. The effects of green spaces on childhood asthma are mixed, with some studies indicating protective effects while others suggest increased risks, influenced by local environmental factors. Air pollutants such as PM 2.5 , NO 2 , and ozone can exacerbate asthma symptoms and along with other environmental factors, contribute to seasonal effects. High temperatures generally correlate with increased asthma risks, though the effects vary by age, sex, and climate. Future research should integrate spatial and temporal methods to better understand the effects of environmental and climate changes on childhood asthma. • Extreme temperatures and precipitation raised childhood asthma risk in summer and winter. • Dust storms in arid and subtropical regions increased asthma hospital admissions. • Green space effects on childhood asthma vary, depending on local environmental factors. • PM 2.5 and ozone worsen asthma symptoms, with effects varying by season. • High temperatures increased asthma risk, with variations by age, sex, and climate.