Biogenic Organic Aerosol as an indicator of the forest abiotic stress

Volatile organic compounds (VOCs) have a substantial impact on the oxidant balance of the lower layers of the atmosphere. As result, they affect tree growth and ecosystem performance. Also, VOCs play significant role in new particle formation process and they change physicochemical properties of the existing particles. Wherein, such ecosystem like forest are the main source of the biogenic VOCs and in the global scale their emissions higher than anthropogenic VOCs. Thus, we investigated the changes of the physicochemical properties of the aerosol particles in forest environment. The measurements were performed applying a Scanning Mobility Particle Sizer, an Aerodynamic Particle Spectrometer and an Aerosol Chemical Speciation Monitor. During measurement campaign, it was observed new particle formation phenomena. Fresh nucleated particles were characterized by low oxidation level and high particle number concentration of the nucleation mode. Wherein, the polydisperse coagulation process was much higher than the condensation growth of the nucleated particles. Also, we determined that the nucleation process of the aerosol particle was related with the trees abiotic stress, which was observed by temperature increase. The analyse of the aerosol mass spectra showed that the methanol (CH3OH, m/z 33), acetone (C3H6O2, m/z 59), methyl-ethyle-ketone (C4H8O, m/z 73) and salicyl-aldehyde (C7H8O2, m/z 123) emissions were identified as heat related. Meanwhile, methanol, acetone and methyl emissions showed great dependency of heat and light. They showed high correlation (>0.9) with one another. However, the salicyl-aldehyde could be assigned to heat stress marker. Thus, we can conclude that biogenic organic aerosol particles can be an indicator of the abiotic stress of the forest and that could to expand understanding of the forest ecosystem. The study is based on the results from national project supported by Lithuanian Council of Research "FOREstRESS"(SIT - 3/2015)Fizinių ir technologijos mokslų centrasVytauto Didžiojo universitetasŽemės ūkio akademij

Study of the aerosol particle filtration efficiency of fabrics used to manufacture non-medical face masks in Lithuania

The global spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) proved to be a challenge for public health. The high demand of medical masks worldwide during the pandemic has led to a critical situation for decision-makers regarding high-quality mask supply. For this period, the World Health Organization has suggested the use of non-medical face masks (also known as ‘community’ masks) in public places to reduce the airborne spread of SARS-CoV-2. In this study, the filtration efficiency of various fabrics widely used in community masks was determined based on two main mask filtering properties: filtration efficiency (FE) and pressure drop (ΔP) according to the recommendations of the CEN Workshop Agreement (CWA) 17553:2020. The combination of FE and ΔP parameters must be considered in order to select suitable materials for public masks. The filtration efficiencies for various fabrics ranged from 6 to 100%. It was found that the composite materials have the highest FE equivalent to the requirements of a medical mask (FE > 95%), that is confirmed by high-quality parameters 16–30 kPa–1. The study found that fabrics of natural fibres (100% cotton) have a higher FE with Ag coating (18–40% before and 29–40% after coating) in the 0.54–1.50 μm particle size range

Seasonal observation and source apportionment of carbonaceous aerosol from forested rural site (Lithuania)

International audienc

Indoor-outdoor relationship of submicron particulate matter in mechanically ventilated building: Chemical composition, sources and infiltration factor.

To evaluate the impact of outdoor particulate pollution on indoor air quality, the chemical composition and sources of submicron aerosol particles (PM1) were studied indoors and outdoors. Measurements were carried out during the heating season from October 15, 2020, to February 8, 2021, at the Center for Physical Sciences and Technologies in Vilnius, Lithuania. Online measurements of PM1 chemical composition were performed using an Aerosol Chemical Speciation Monitor (ACSM (organics, sulfate, and nitrate)) and an Aethalometer (equivalent black carbon, BC). In parallel with the online measurements, filter-based elemental composition and 14C analysis of PM1 were performed using a Particle-Induced broad-beam X-ray Emission (PIXE) and a Single Stage Accelerated Mass Spectrometer (SSAMS), respectively. The source apportionment results showed a dominant contribution of biomass burning to the total carbonaceous aerosol particles, including primary (30%) and secondary (40%) fractions. According to the enrichment factors, the main source of trace elements was road dust resuspension (30%), while anthropogenic emissions accounted for only 13% of trace elements. The infiltration factor (Finf) of all studied PM1 constituents was low (Finf∼0.03). This result indicates that the three-stage building filter system (G4-F7-F9) provides high protection against particle pollution of different origins and significantly reduces indoor exposure to PM1. The changed chemical composition of indoor PM1 can be attributed to species-specific evaporation and some minor indoor sources

Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM₁) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m⁻³ and black carbon (BC) up to 17 µg m⁻³ were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (¹⁴C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OC_nf) was the dominant fraction of PM₁, with the primary (POC_nf) and secondary (SOC_nf) fractions contributing 26–44 % and 13–23 % to the total carbon (TC), respectively. 5–8 % of the TC had a primary fossil origin (POC_f), whereas the contribution of fossil secondary organic carbon (SOC_f) was 4–13 %. Non-fossil EC (EC_nf) and fossil EC (EC_f) ranged from 13–24 and 7–13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning