Toxicity testing of nonwovens used for production of respiratory protective equipment.

OBJECTIVES: During the covid-19 pandemic, protective equipment such as respirators and masks were widely used to protect respiratory tract. This disposable protective equipment is usually made from plastic fibre-based nonwoven fabrics. If used masks and respirators are improperly discarded, they pollute the environment by becoming a source of micro and nanoplastics. The aim of the study was to find out how stable the materials of protective equipment are and how released nano and microplastics can affect aquatic and soil organisms. MATERIALS: The input materials used to produce respirators and masks were tested for their thermal stability and resistance to the release of plastic particles into the environment. To determine the thermal stability of the materials, a simultaneous thermal analysis - thermogravimetry (TGA) and differential scanning calorimetry (DSC) were performed. RESULTS: Materials of masks and respirators are stable at temperatures common to temperate climate zone. However, the possible effects of chemical reactions of the materials with the environment were not considered during the measurement. The materials were also subjected to ecotoxicity tests according to European standards. CONCLUSION: While the leachate obtained by shaking the materials in water did not show acute toxicity to the selected aquatic organisms, the material itself had a significant effect on selected soil organisms (springtails).

Biochar – an efficient sorption material for the removal of pharmaceutically active compounds, DNA and RNA fragments from wastewater

Wastewaters are considered a remarkable source of micropollutants capable of influencing the environment both directly and indirectly. Here we tested porous ecological carbon (Biochar), an effective sorbent material for removing pharmaceuticals, drugs, and their metabolites found in wastewaters. The tested Biochar type was first characterised and used for adsorption experiments of selected micropollutants from a municipal WWTP (wastewater treatment plant) effluent sample. The sorption efficiency was studied on selected pharmaceuticals due to their common presence in aquatic ecosystems. The results show that the studied Biochar type removed the pharmaceuticals with high efficiency (above 90%), so this material can potentially be applied in wastewater treatment. We achieved greater than 99% efficiency in total RNA removal from wastewater. Wastewater might contain infectious RNA fragments of the SARS-CoV-2 virus. However, Biochar can be used as a sorbent in wastewater treatment to remove antibiotic resistance genes. We have also observed a total DNA removal ability of Biochar. On the other hand, the total number and antibiotic-resistant coliform bacteria and enterococci were not changed after Biochar wastewater treatment.