Deposition of airborne cyanobacteria and microalgae in the human respiratory tract (Baltic Sea coastal zone, Poland).

Scientific research confirms the harmful effects of airborne cyanobacteria and microalgae. However, determining human exposure to these microorganisms remains a challenge. The six-stage Tisch impactor was used to collect bioaerosols from April to September 2020 in the coastal zone of the southern Baltic. The MPPD model was used for estimation of regional, lobar, and generation deposition of microorganisms in human respiratory tract. The mass deposition fraction of cyanobacteria and microalgae in the head region gradually increased with the aerosol size. The maximum deposition fractions in the trachea, bronchial, and the pulmonary region were found for particles between 2.1 and 3.3 μm. The contribution of cyanobacteria and microalgae was the highest in the head region. The majority of microorganisms found in pulmonary region dominated in particles smaller than 2.1 μm. Exposure to the ambient bioaerosols may have an adverse impact on the human health in the region of southern Baltic Sea.