Airborne microplastic is an emerging and widespread pollutant yet is still under-characterised and insufficiently understood. Detailed description of microplastic air pollution is crucial as it has been identified in human lungs and remote locations, highlighting the atmosphere as a medium of MP dispersion and transportation. The lack of standardization of methods for measuring and further monitoring of microplastic pollution is an obstacle towards assessment of health risks. Since the first recognition of MP presence in the atmosphere of Krakow in 2019, this research was conducted to further characterise and develop the methods for qualitative and quantitative analysis of airborne microplastic (attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR); pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS); scanning electron microscopy-energy dispersive spectroscopy SEM-EDS) and pre-treatment of samples. The data were gathered in seven cycles from June 2019 to February 2020. The methods used in the study allowed the identification and analysis of the changing ratio of the different types of synthetic polymers identified in the atmospheric fallout (low-density polyethylene, nylon-66, polyethylene, polyethylene terephthalate, polypropylene and polyurethane). Observations of interactions between microplastic particles and the environment were conducted with analyses of surface changes due to degradation. Different phases attached to the microplastics surfaces, with some of the inorganic contaminants transported on these surfaces determined also to be of anthropogenic origin. The methodology proposed in this study allows further characterisation of microplastic from multiple locations to provide highly comparable data, leading to identification of the sources of this phenomenon, as well as seasonal changes.

Particulate matter (PM) emitted into the atmosphere from a hard coal-fired power plant equipped with a pulverised fuel boiler was studied using X-ray diffractometry (XRD), inductively coupled plasma mass spectrometry (ICP-MS), and scanning electron microscopy fitted with X-ray energy-dispersive spectrometry (SEM-EDS). The PM emitted from coal-fired power plants is rarely studied, in contrast to fly ash collected during flue gas cleaning. The material of PM is composed of particles differing in size, morphology, and chemical composition. Aluminosilicate spherical particles dominate, but other particles also occur (irregular aluminosilicate particles, char particles, irregular particles of quartz, Fe oxides, particles rich in Fe, Cr and Ni, barite, and others). The size of other particles varies from 50 μm to 250 μm. The emitted PM is strongly enriched in several elements in comparison to average coal ash or upper continental crust (e.g., Ag, Bi, Cd, Cr, Hg, Mo, Ni, Re, Se, and Zn). The content of bioavailable, water-soluble fraction (containing S, Ca, K, Na, Cl and subordinate Zn and Ni) is ca 5%. The broad variation of the size and composition of the emitted PM indicates the potential environmental impact and possibility of dispersion over a large area.

Eight aerosol samples were collected in Krakow using a low-volume sampler in February and March 2019 during variable meteorological conditions and times of the day, to study their single particles’ properties (size, morphology and chemical composition analyzed using a scanning electron microscope fitted with an energy-dispersive spectrometer) and microbiological characteristics. The content of particles of different chemical compositions larger than 2.5 μm was low. Considering the number of the particles, submicron particles strongly dominated with a high content of ultrafine particles (nanoparticles). Tar ball-type particles were relatively common in the studied samples, while soot was the dominant component. Soot was present as small agglomerates composed of few particles, but also as bigger agglomerates. Metal-containing particles of various chemical characteristics were abundant, with transition metals commonly occurring in these particles. The physicochemical characteristics of aerosols indicate that despite a relatively low mass concentration, their adverse health impact could be very strong because of the high content of nanoparticles, the abundance of soot and other fuel combustion-related particles, and the high incidence of transition metal-rich particles. Microbiological analysis was based on cultures on both solid and liquid agar. The MALDI-TOF method was used for species identification—for bacteria and fungi. Twelve different species of bacteria were isolated from the collected samples of aerosols. The most frequently isolated species was Gram-positive sporulating Bacillus licheniformis. The isolated mold fungi were of the genus Aspergillus.

During single particle analysis of aerosol in Kraków (Poland) we noticed a new component, that is, aggregates of TiO₂ particles. These aggregates are from 0.5 to 4 μm and are composed of individual particles whose size typically varies from between 100 and 350 nm. Smaller particles (below 100 nm) also occur. TiO₂ particles are relatively abundant in the summer. The size distribution of the particles corresponds to “pigmentary” TiO₂, which indicates that they could be derived from paints and building materials. TiO₂ particles were not previously identified in aerosol samples in Kraków, and therefore this phenomenon is likely to be related to the common usage of new building materials and paints. A review of the literature suggests that TiO₂ particles, especially within the nanosize range, could result in health and environmental impacts; however, evaluation of the actual threat is difficult.

Ash samples from biomass combustion or co-combustion with coal were analysed. The aim of this study of ash was to determine its mineral and chemical composition, and the chemical composition of solutions obtained during one-step water extraction. Besides the chemical analysis, X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) were applied. The mineral and chemical composition of ash samples differ strongly. The content of heavy metals in the ash is generally low, but in some samples the limits of the content of some elements determined for fertilizers or soil amendments are exceeded. The relatively poor correlation between the concentration in leachate and bulk content in ash indicates that numerous elements are present in different forms in the studied samples. The results indicate that the potential use of biomass ash, or ash from biomass-coal co-combustion, requires complex studies that explore ash and leachates.