Extension of the sorting instructions for household plastic packaging and changes in exposure to bioaerosols at materials recovery facilities

Abstract

The aim of this study was to assess how extending the sorting instructions for plastic packaging would affect the exposure of workers working at materials recovery facility (MRF) to dust, endotoxins, fungi and bacteria, taking into consideration other factors that could have an influence on this exposure. Personal sampling was carried out at four MRFs during six sampling campaigns at each facility, both in sorting rooms and when the workers were involved in "mobile tasks" away from the rooms. The data was analysed by describing the extension of sorting instructions both using a qualitative variable (after vs before) and using data for the pots and trays recycling stream, including or excluding plastic film. Overall, before the extension of the sorting guidelines, the geometric mean of personal exposure levels in sorting rooms was 0.3mg/m(3) for dust, 27.7 EU/m(3) for endotoxins, 13,000 CFU/m(3) for fungi and 1800 CFU/m(3) for bacteria. When workers were involved in mobile tasks away from the rooms, these averages were 0.5mg/m(3), 25.7 EU/m(3), 28,000 CFU/m(3) and 5100 CFU/m(3) respectively.The application by households of instructions to include pots, trays and film with other recyclable plastic packaging led to an increase in exposure to endotoxins, fungi and bacteria at MRFs. For an increase of 0.5 kg per inhabitant per year in the pots, trays and film recycling stream, exposure in sorting rooms rose by a factor of 1.4-2.2, depending on the biological agent. Exposure during mobile tasks increased by a factor of 3.0-3.6. The age of the waste amplified the effect of the extension of sorting instructions on exposure to fungi, bacteria and endotoxins. Factors that had a significant influence on the exposure of workers to dust and/or bioaerosols included the presence of paper, newspapers and magazines in the sorted waste, the order in which incoming waste was treated and the quality of the ventilation system in the sorting rooms. The levels of exposure observed in this study highlight the need to implement appropriate preventive measures against bioaerosols at MRFs for dry waste. There are grounds to justify these preventive measures, both inside sorting rooms and for the MRF as a whole, regardless of whether the decision to extend sorting instructions for household plastic waste is adopted.

Keywords: Bioaerosol; Endotoxins; Fungi; Occupational exposures; Plastics; Waste management.