Western Macedonia, located in North-western Greece, is largely dominated by lignite mining and lignite-fired power plants, which are a significant part of the country’s economy. However, the electricity generation and the related activities are among the greatest sources of air pollutants. In this study, we focus on the air quality of Western Macedonia based on measurements of Particulate Matter (PM_2.5 and PM₁₀) over a 12-year period (from 2010 to 2021) and a sampling of PM-bound trace elements over the course of 12 months (from December 2017 to November 2018). The analysis revealed an overall decrease of PM_2.5 and PM₁₀ concentrations over the study period. In general, the concentrations of PM exhibited seasonality patterns associated with the weather conditions and the local sources of air pollutants. These major sources of air pollution are the lignite mining processes, the emissions from the lignite-fired power plants, and the anthropogenic emissions from the biomass burning and heating systems. In addition, the analysis of the PM-bound trace elements revealed some differences; the elemental profiles of both PM_2.5 and PM₁₀ were quite similar, while the most abundant elements (Ca and Si) indicate that the main emission sources were related with the mining activities and the coal combustion.

In this study, the AirQ+ software proposed by the World Health Organization (WHO) was applied in order to assess the health endpoints associated with the long-term exposure to PM_2.5 in Attica Region, Greece. For this purpose, we analyzed the daily average concentrations of PM_2.5 registered by the air quality monitoring stations in the region, from 1 January 2007 to 31 December 2018. Although there was a decreasing trend in PM_2.5 concentrations levels, the levels of PM_2.5 exceeded the AQG (Air Quality Guidelines) limit value (annual value: 5 μg/m³) established by the WHO. The findings revealed that the burden of mortality (from all-natural causes) at people above 30 years old associated with PM_2.5 exposure was 4752 [3179–6152] deaths in 2007 and 2424 [1598–3179] deaths in 2018. In general, the attributable mortality from specific causes of deaths (e.g., lung cancer, IHD (ischemic heart diseases) and stroke) in people above 25 years old decreased between the years, but the mortality from COPD (chronic obstructive pulmonary diseases) was stable at 146 [79–220] deaths in 2007 and 147 [63–244] deaths in 2018. We also found differences in mortality cases from IHD and stroke among the age groups and between the years 2007 and 2018.

The lockdown implemented to tackle the spread of the COVID-19 pandemic had a positive impact on air quality. Globally, studies have shown that air pollutant levels decreased temporally during the restriction measures. In this study, we evaluated the impact of COVID-19 restrictions on the air quality of Western Macedonia, Greece, using the concentrations of PM_2.5 and PM₁₀ along with meteorological data from the Air Quality Monitoring Stations (AQMS) operated by the Lignite Center of Western Macedonia. In Western Macedonia, previous studies have identified a general reduction in air pollutant levels during the last decade due to the coal phase-out plan for power generation. During the lockdown, the levels of PM_2.5 and PM₁₀ decreased further. The reduced emissions from the local mining activities and lignite-fired power plant electricity generation, as well as the weather conditions, seem to contribute to improving air quality.

The World Health Organization (WHO) has developed the AirQ+ software in order to estimate the magnitude of the impact of air pollution on health in a given population. In this study, the AirQ+ was applied to calculate the short-term effects attributed to PM_2.5, NO₂ and O₃ in the Attica Region, Greece. Based on the health endpoints handled by the AirQ+ software, we evaluated the impact of air pollutants on hospitalizations and work days lost. In 2015, 69,460 and 48,972 patients were admitted to the hospitals in the Attica Region due to circulatory and respiratory diseases, respectively. For the estimation of the attributable burden, the time-series of PM_2.5, NO₂ and O₃ concentrations for the year 2015 are used. The burden attributed to PM_2.5 is 297 (55–546) and 441 (0–953) hospitalizations for circulatory and respiratory diseases, respectively. NO₂ and O₃ also contribute to the burden of hospitalizations for respiratory diseases. Specifically, 424 (271–576) and 381 (61–718) respiratory-related hospitalizations are attributed to NO₂ and O₃, respectively. An important effect of PM_2.5 exposure also handled by the AirQ+ is work absenteeism. Based on health statistics for Greece, the number of self-reported work days lost per year due to illness are 14.7 days per employed person. The attributable burden of PM_2.5 is 0.33 (0.28–0.38) work days lost (per employed person per year). In conclusion, the short-term effects of air pollution exposure has a great impact on human health.

In the lignite basin of Western Macedonia, Greece, the lignite long-lasting exploitation and the mining activities have an impact on the environment and air quality. In this study, we focus on the air quality in the cities of Kozani, Kastoria, Grevena and Florina in Western Macedonia, Greece to assess the levels of air pollutants concentrations and investigate their variations at different timescales. The particle pollution in the region exhibits seasonality patterns associated with the weather conditions and the local emissions sources. As for the ozone pollution in the region, there is a minor number of alert days that exceed the European Union (EU) limit value, but ozone concentrations are high based on World Health Organization (WHO) standards. Also, we evaluate the air quality through the Air Quality Health Index (AQHI) which is a health risk-based air pollution index. We concluded that the majority of days found in the category of “moderate” health risk associated with the air quality, while for a small number of days the relevant health risk is “high”.