Microplastics inhalation: evidence in human lung tissue

Plastics are widely used by society and their degradation into millimetre fragments, called microplastics, is a growing cause of concern due to the potential adverse effects on the environment and human health. Microplastics are also present in the air and are inhaled by humans, which may cause deleterious effects on the respiratory system. There is no information whether inhaled microplastics would be incorporated in lung tissue. In this study, we determined the presence of microplastics in human lung tissues. The samples were collected in peripheral and central regions of the lung from 10 cases of non-smoking individuals who have lived in the city of São Paulo for the past five years. As an additional measure of lung tissue control, samples were collected from two stillborn. Procedural blanks were used during all sample handling and analysis procedures. All microplastic particles were characterized in terms of morphology and chemical composition. Raman microspectroscopy was used for the chemical characterization of possible polymeric materials. Polymeric particles (n = 7) and fibres (n = 2) have been observed in five of the ten cases. Polymeric particles (n = 7) and fibres (n = 2) have been observed in five of the ten cases. All polymeric particles were smaller than 10 µm in size and the polymers determined were polyethylene and polypropylene, no fibres were seen. Deleterious health outcomes may be related to the heterogeneous characteristics, sources, and fates of these contaminants in the respiratory system following inhalation.