Heat related mortality in the two largest Belgian urban areas: A time series analysis

Abstract

BackgroundSummer temperatures are expected to increase and heat waves will occur more frequently, be longer, and be more intense as a result of global warming. A growing body of evidence indicates that increasing temperature and heatwaves are associated with excess mortality and therefore global heating may become a major public health threat. However, the heat-mortality relationship has been shown to be location-specific and differences could largely be explained by the most frequent temperature. So far, in Belgium there is little known regarding the heat-mortality relationship in the different urban areas. ObjectivesThe objective of this study is to assess the heat-mortality relationship in the two largest urban areas in Belgium, i.e. Antwerp and Brussels for the warm seasons from 2002 until 2011 taking into account the effect of air pollution MethodsThe threshold in temperature above which mortality increases was determined using segmented regressions for both urban areas. The relationship between daily temperature and mortality above the threshold was investigated using a generalized estimated equation with Poisson distribution to finally determine the percentage of deaths attributable to the effect of heat. ResultsAlthough only 50km apart, the heat-mortality curves for the two urban areas are different. More specifically, an increase in mortality occurs above a maximum temperature of 25.2°C in Antwerp and 22.8°C in Brussels. We estimated that above these thresholds, there is an increase in mortality of 4.9% per 1°C in Antwerp and of 3.1% in Brussels. During the study period, 1.5% of the deaths in Antwerp and 3.5% of the deaths in Brussels can be attributed to the effect of heat. The thresholds differed considerably from the most frequent temperature, particularly in Antwerp. Adjustment for air pollution attenuated the effect of temperature on mortality and this attenuation was more pronounced when adjusting for ambient ozone. ConclusionOur results show a significant effect of temperature on mortality above a city-specific threshold, both in Antwerp and in Brussels. These findings are important given the ongoing global warming. Recurrent, intense and longer episodes of high temperature and expected changes in air pollutant levels will have an important impact on health in urban areas.

Impact of Short-Term Exposure to Extreme Temperatures on Mortality: A Multi-City Study in Belgium

“…Baccini et al (2008) found a daily maximum temperature associated with the minimum mortality rate at 23.3 °C in Western Europe cities [ 6 ], 21.8 °C, 23.9 °C, and 24.1 °C in Zurich, London, and Paris, respectively. In a previous investigation carried out in Belgium in the cities of Antwerp and Brussels [ 18 ], minimum risk thresholds were observed at a daily maximum of 25.2 °C and 22.8 °C, respectively (considering a lagged average of 0–3 days) while Martinez et al (2018) considered a minimum mortality at 26.0 °C for daily maximum temperature in Antwerp [ 17 ]. In the present study, the temperature–mortality relationships were separately investigated in nine agglomerations.…”

“…The association between cold and mortality may also change with global warming and this is not well understood [ 12 , 13 , 14 , 15 ]. Most studies investigating the temperature–mortality relationship mainly focused on the effects of heat on all-cause mortality as in Belgium [ 16 , 17 , 18 ] where cold-related mortality nor cause-specific temperature–mortality relationships have been properly investigated.…”

“…Since the shape of the relationship between temperature and mortality can vary between areas [ 19 ], for instance within Europe [ 20 ] and even between nearby cities as in Belgium [ 18 ], it is important to investigate this association at the city and country levels but also to identify vulnerability factors depending on more local conditions such as urban characteristics (Sera et al, 2019) or specific individual characteristics of the population [ 21 ]. Investigations in regions with different environmental and climatic conditions contribute to the identification of risk factors to be addressed in the planning of public health interventions and prevention strategies [ 22 ].…”

A game engine based application for visualising and analysing environmental spatiotemporal mobile sensor data in an urban context

“…The general increase in hot days (days with a maximum air temperature above 30 °C) is driven by climate change and poses a major health threat to city dwellers (Schuster et al, 2017;De Troeyer et al, 2020). The intensity of the urban heat island effect is strongly dependent on the urban structure, such as the number and distribution of green infrastructure (Kumar et al, 2019;Sinha et al, 2021) and the degree of sealing.…”

The State-of-the-Art of Urban Climate Change Modeling and Observations

“…Urban citizens are exposed to additional heat stress due to the urban heat island with warmer near-surface air temperature in urban centers compared to the surrounding areas. As the urban dwellers are unable to recover from extreme temperature during daytime, the urban heat island (UHI) effect can be particularly detrimental to public health during heat waves (De Troeyer et al 2020). Land-use and land-cover changes (LULCC) are expected to strongly impact climate warming trajectories in the near future (Cugnon et al 2019;IPCC 2019;Kuang 2020b).…”