Dustiness and bio-aerosol exposure in sorting recyclable paper

In Denmark recycling of household waste is a growing industry and recycled paper is the major source for the Danish pulp production. Paper for recycli ng may come from various sources including households and industry. The pap er is collected separately, but the segregation process may not always be e fficient and the paper may be high in microbial content. For workers sortin g recyclable paper, data are few on personal exposure to bio-aerosols and a comparative study, therefore, was carried out to establish base-line infor mation. Workers sorting clean paper (items of mail) were included for compa rison. The data obtained were compared with data from the literature on exp osure of waste collectors to bioaerosols. The potential of recyclable paper to emit dust (dustiness) and micro-organisms was characterized in the labo ratory using a rotating drum dustiness tester and mixed household waste was included for comparison. The study indicated that workers sorting recyclab le paper were exposed to high levels of bio-aerosols compared to workers so rting clean paper. Workers sorting recyclable paper were exposed to bio-aer osols at similar or higher levels than workers collecting the paper. Howeve r, the exposure level was comparable with or lower than the levels seen in workers collecting mixed household waste. For dust and endotoxin the paper sorting workers were exposed to levels below existing or proposed occupatio nal exposure limits (OELs), but for viable micro organism exposure may exce ed proposed OELs. Dustiness of recyclable paper was high in terms of dust a nd endotoxin compared with mixed household waste. With regard to viable bac teria, dustiness of paper was at the level of mixed household waste. In pri nciple, paper collected for recycling should be low in microbial content le ading to a low bio-aerosol exposure for workers handling the paper. However , recyclable paper may be high in microbial dustiness. This finding indicat es low standards of separation in households and/or contamination of the co llected paper from dirty containers or collection vehicles.