Air pollution is responsible for many adverse effects on human beings. Thermal discomfort, on the other hand, is able to overload the human body and eventually provoke health implications due to the heat imbalance. Methods: The aim of the presented work is to study the behavior of two bio-climatic indices and statistical characteristics of the air quality index for Sofia city-the capital of Bulgaria for the period 2008-2014. The study is based on the WRF-CMAQ model system simulations with a spatial resolution of 1 km. The air quality is estimated by the air quality index, taking into account the influence of different pollutants and the thermal conditions by two indices, respectively, for hot and cold weather. It was found that the recurrence of both the heat and cold index categories and of the air quality categories have heterogeneous space distribution and well manifested diurnal and seasonal variability. For all of the situations, only O-3 and PM10 are the dominant pollutants-these which determine the AQI category. It was found that AQI1, AQI2, and AQI3, which fall in the “Low” band, have the highest recurrence during the different seasons, up to more than 70% in some places and situations. The recurrence of AQI10 (very high) is rather small-no more than 5% and concentrated in small areas, mostly in the city center. The Heat index of category “Danger” never appears, and the Heat index of category “Extreme caution” appears only in the spring and summer with the highest recurrence of less than 5% in the city center. For the Wind-chill index category, “Very High Risk” never appears, and the category “High Risk” appears with a frequency of about 1-2%. The above leads to the conclusion that both from a point of view of bioclimatic and air quality indices, the human health risks in the city of Sofia are not as high.
Although a number of epidemiological studies have examined the effects of non-optimal temperatures on mortality in Europe, evidence about the mortality risks associated with exposures to hot and cold temperatures in Bulgaria is scarce. This study provides evidence about mortality attributable to non-optimal temperatures in adults aged 65 and over in Sofia, Bulgaria, between 2000 and 2017. We quantified the relationship between the daily mean temperature and mortality in the total elderly adult population aged 65 and over, among males and females aged 65 and over, as well as individuals aged 65-84 and 85 years or older. We used a distributed lag non-linear model with a 25-day lag to fully capture the effects of both cold and hot temperatures and calculated the fractions of mortality attributable to mild and extreme hot and cold temperatures. Cold temperatures had a greater impact on mortality than hot temperatures during the studied period. Most of the temperature-attributable mortality was due to moderate cold, followed by moderate heat, extreme cold, and extreme heat. The total mortality attributable to non-optimal temperatures was greater among females compared to males and among individuals aged 85 and over compared to those aged 65 to 84. The findings of this study can serve as a foundation for future research and policy development aimed at characterizing and reducing the risks from temperature exposures among vulnerable populations in the country, climate adaptation planning and improved public health preparedness, and response to non-optimal temperatures.
Human health vulnerability (HHV) to different climate change-related phenomena, that is, summer heat extremes, is related to the exposure, sensitivity, and adaptive capacity of the affected entities. The current research is an empirical regional assessment of the human health effects of summer heat extremes in the Romania-Bulgarian Danube floodplain Calafat-Vidin-Turnu Magurele-Nikopol (CV-TMN) sector. The external biophysical and socioeconomic factors that shape the vulnerability are supported by the climate approach. The research relies on processing meteorological data from the most representative climate stations in the study area based on which some indicators-significant for measuring the impact on human health-were computed (e.g., number of extremely hot days, number of tropical days, number of tropical nights) and integrated into a composite summer heat extremes index (SHEI). To assess HHV to summer heat extremes, the vulnerability framework was completed by the internal socioeconomic factors revealed by the characteristics of the population living in urban and rural settlements in terms of demographic, health provisions, and quality of indoor living spaces. Finally, the authors computed the index of human health vulnerability to summer heat extremes (HHVI) as the Hull Score at the level of territorial local administrative units.
