The European region with the highest number of heat-related deaths remains a puzzle due to its abundance of green spaces.
The green lights on the pharmacy’s cross displayed a temperature of 38C for the second consecutive day. Despite this warning, the crowds in the center of Osijek seemed unaffected. Davor, a 47-year-old bike courier for Wolt food delivery service, stated that the heat was not a problem for him and his job.
This small city in Croatia is known as Europe’s deadliest place for extreme heat, although many residents may not be aware of it. According to a study published in the Lancet medical journal, Osijek has experienced more fatalities due to hot weather in the last 20 years compared to any other city in Europe. The researchers analyzed data from 854 major cities in Europe and concluded that Croatians have the highest risk of death from heat-related causes.
Despite the potential hazards, there has been insufficient effort to ensure the safety of individuals – or to investigate the reasons behind the alarming mortality rate. Medical professionals and researchers assert that the health emergency is much more severe than commonly acknowledged, as the general population is ignorant of the severe impact of heat and policymakers are not adequately equipped to handle its intensification.
Lidija Srnec, a climate scientist at the Croatian Meteorological and Hydrological Service, noted that in the previous century, there were some risks, but they were not as frequent. She pointed to a computer chart with color-coded temperature alerts in her office in Zagreb, showing that currently, the duration and intensity of red alerts have increased.
Due to the increase of carbon pollution in the atmosphere, sunlight is being trapped like a greenhouse, resulting in Europe experiencing intense heat waves. Last summer, approximately 70,000 people lost their lives due to the extreme temperatures, and this number may increase even further in 2023, which was the hottest year on record. Doctors emphasize that the impact of a heatwave is not only determined by climatic conditions, but also by the vulnerability of individuals and how effectively they respond.
The city of Osijek, located near the border of Serbia in Croatia, may not be expected to experience extreme heat. While the surrounding agricultural region of Slavonia is warmer than the capital city of Zagreb, it is not as hot as the coastal area of Dalmatia, which is popular among tourists for cities like Dubrovnik and Split. Residents report that the healthcare in Osijek is on par with that of the rest of the country. The average age of residents has increased since Croatia’s EU accession in 2013, but this factor was taken into consideration by the researchers.
In addition to its enigmatic atmosphere, Osijek boasts natural features that help maintain its cool climate. Situated on the Drava River, which eventually merges with the Danube 12 miles away, the city is surrounded by Kopački Rit, one of the largest wetlands in Europe. During the rule of the Austro-Hungarian empire, city planners incorporated parks into the urban landscape.
Matijana Jergović, an epidemiologist at the Andrija Stampar Teaching Institute of Public Health in Zagreb, shared that Osijek is abundant in green spaces. She mentioned that despite growing up in a concrete-filled working-class area of Osijek, she frequently sought refuge in the nearby rivers and forests.
This dilemma is not exclusively a concern for Croatia. The search for solutions in both Osijek and Zagreb, where scorching temperatures have only marginally decreased fatality rates, may aid cities in Europe that are facing extreme heat as the climate becomes increasingly inhospitable for human life.
During a hot August morning in Osijek, while pigeons were drinking from a fountain and a shaggy dog was resting on the water jets, the streets were mostly empty but the terraces were full. An Indian chef who had previously worked in Dubai, where the temperatures were even higher, stated that he didn’t find the Croatian heat to be unbearable. He casually mentioned that Osijek reminded him of his hometown in Uttarakhand.
Medical professionals have put forth several hypotheses to clarify the number of fatalities. One possible reason is the stagnant or slow-moving bodies of water surrounding Osijek, resulting in high humidity levels. This high moisture content in the air decreases the rate at which sweat evaporates from the skin, making it difficult for the body to release heat. Experts have cautioned that in certain regions, the combination of heat and humidity, known as “wet-bulb” temperatures, are approaching the maximum threshold that the human body can tolerate.
According to Pierre Masselot, lead author of the study from the London School of Hygiene & Tropical Medicine, the Lancet study did not take humidity into account in its models. However, recent research indicates that humidity does not have a significant impact on mortality rates. While it may have some effect, it is not a major factor in epidemiological terms.
There are also underlying medical conditions. Medical professionals refer to heat as a dangerous threat because only a small number of deaths attributed to it are actually recorded. While some individuals may pass away from heatstroke while working on farms or construction sites, with official records listing heat as the primary cause of death, many others die while in hospitals or nursing homes as they battle heart and respiratory issues. High temperatures put strain on already weakened bodies and warm nights hinder their ability to recuperate. This leads to a noticeable increase in deaths that is only reflected in statistical data.
Researchers suggest that there are two possible scenarios for how this could occur in Osijek. A recent investigation of individuals who survived the Vietnam war in 2020 discovered a link between exposure to war and an increased risk of heart disease later in life, especially among women who, for various reasons, have higher mortality rates during heatwaves. In Osijek, where there are still visible damages from shells that were dropped during the country’s war for independence from Yugoslavia in 1991, it is possible that residents may have unseen emotional wounds that make them more susceptible to the effects of heat.
Jergović explained that when they were children, their parents placed them on buses without knowing where they would eventually end up. At 13 years old, Jergović fled to Austria for three months and also assisted other child refugees in finding host families there.
Diet could also play a role. Croatia has the largest percentage of overweight or obese individuals in Europe. Along the coast, there is a preference for a Mediterranean diet consisting of fish, vegetables, and wine, rather than meat, potatoes, and beer. However, cities like Osijek in the Slavonia region have a cuisine that is high in fat, similar to that of central Europe. The displayed menus of restaurants in Osijek offer hearty dishes that can lead to clogged arteries and increased blood pressure.
According to Dinko Pesić from Zeleni Osijek, older residents in Slavonia are reluctant to give up traditional dishes such as fatty pork sausages and spicy hot stews. However, these foods may not be suitable for the increasingly severe weather conditions.
At present, scientists posit that the justifications are merely informed conjectures. However, they caution that unless immediate action is taken, the issue will exacerbate.
On the shores of the Drava river, a continuous buzzing signals a troubling aspect of Croatia’s deteriorating climate. According to Branimir Hackenberger, a biologist at the University of Osijek who studies insect populations, a person sitting by the river during summer can expect to be bitten by mosquitoes 300 times per hour. He also stated that in Osijek, the number of mosquito attacks per hour exceeds even those in Burkina Faso.
Croatia has been hit by summer heatwaves followed by flash floods that have helped mosquitoes breed. The insects do not yet carry diseases such as malaria, said Hackenberger, but the ecological conditions for infectious diseases to spread are already there. “All we need is the trigger.”
Croatia has limited ability to impact the increase in temperatures, aside from reducing its own greenhouse gas emissions. According to experts, the country can still take simple measures to protect lives during heatwaves, such as issuing warnings and checking on those who are more susceptible.
The Ministry of Health in Croatia acknowledged the findings of the Lancet study, but did not conduct an analysis on why Osijek and Croatia as a whole were heavily impacted. They have an existing early warning system and recommendations for heat safety. However, there is no mention of when their heat-health action plan will be released.
Experts suggest that individuals have the ability to adjust their actions. While standing outside a football stadium in Zagreb during a match, Željka Štaub, a nurse working for a mobile medical company, recommended that people stay hydrated and avoid being outdoors if possible. She also emphasized the importance of monitoring those who are drinking alcohol in the heat.
In the future, cities may be able to maintain cooler temperatures by decreasing traffic and replacing concrete and asphalt with green spaces and trees. This is because the urban heat island effect, which causes cities to be warmer than their surrounding areas due to heat generation and absorption of sunlight, can be reduced.
Hackenberger remarked that Osijek had taken a misguided path. As we drove down a street flanked by small trees and towering two-story homes, he pointed out that the city’s administration had made the decision to replace the taller trees in certain areas with shorter ones, resulting in minimal shade. This lack of foresight did not consider the future heat.
He remarked that three decades ago, these rooftops would have been hidden from view due to all the vegetation.