Bioaerosol in Composting Facilities: A Survey on Full-Scale Plants in Italy

Bioaerosols lead to human health diseases and composting plants are one of the main sources among human activities. In this study, a survey was conducted on such plants to evaluate bioaerosol risk management. A questionnaire was used to collect information on plant location, process types, collective and personal protective equipment, bioaerosol and particulate matter monitoring data, and occupational surveillance. We examined the data produced by 11 plants located in Italy. Self-control bioaerosol monitoring showed a global contamination index mean of 9908 CFU/m3 underlining a higher concentration (a) in plants with only aerobic process (CPs) with respect to plants that also combined anaerobic treatment of the waste (ADCPs) (p < 0.05) and (b) in facilities with biocells with respect to windrows (p < 0.01). Workers are generally more exposed when working without vehicles. Some areas such as pre-treatment and screening are more prone to higher bioaerosol concentrations, requiring more efficient collective protective equipment. Particulate matter monitoring showed concentration in line with occupational exposure limits for inhalable dust (1862 ± 1729 μg/m3) and breathable dust (276 ± 126 μg/m3), however, organic particle exposure risk assessment has to be carefully reviewed. Improvements in the training program, process design, and health surveillance are desirable as major preventive tools.