Assessment of particulate matter exposure associated with biomass storage in urban heating plant

• PM levels rise significantly during woodchip loading at biomass storage sites. • PM2.5 exceeded WHO 24h limit for 14.2% of monitored time near urban heating plant. • Particulate concentrations at 50 m exceeded WHO limits up to 8.7 times. • No significant PM reduction was observed beyond 100 m from the woodchip pile. • Findings support need for dust control to protect health of workers and residents. This study assessed the airborne particulate matter (PM) in urban heating plants, potentially affecting respiratory health in workers and nearby residents. The objectives of this study were to characterize occupational exposure during chip-loading activities and to evaluate ambient PM concentrations in the surrounding environment. Occupational exposure was assessed in accordance with the relevant standards using the Temtop M2000C, while continuous ambient monitoring was conducted with the AirNote device. The results indicate a significant increase in PM concentrations during woodchip loading activities. Mean PM2.5 concentrations were 24.03 µg/m 3 during loading and 8.07 µg/m 3 during non-loading, while PM10 levels were 38.75 µg/m 3 and 12.80 µg/m 3 , respectively. Continuous monitoring revealed that daily mean PM2.5 concentrations were above the WHO 24-h guideline value of 15 µg/m 3 on 3 days. The maximum daily mean PM2.5 concentration was 43.7 µg/m 3 , while the median daily mean was 22.5 µg/m 3 . For PM10, the maximum daily mean reached 70.9 µg/m 3 and the median daily mean was 35.6 µg/m 3 , with exceedance of the WHO 24-hour guideline of 45 µg/m 3 observed on one day. Distance from the woodchip pile also had a significant effect on PM concentrations (p < 0.001), with short-term mean levels at 50 m exceeding the WHO 24-h guideline value by 2.9 times for PM2.5 and 1.6 times for PM10. These guideline values are provided for context only, as they represent 24-hour mean concentrations and not instantaneous limits. Beyond 100 m, no further significant reduction in PM levels was observed. Biomass storage operations can cause temporary PM exceedances, particularly during handling and near storage areas. These findings underscore the importance of implementing mitigation strategies to reduce airborne particulate emissions.