Novel approach for monitoring of PM10 concentration in cage-free laying hen houses

This study presents a novel approach for monitoring PM10 concentrations in cage-free laying hen houses using a light-scattering method combined with intermittent sampling. Traditional methods are either unsuitable or labor-intensive for long-term use. The goal was to enable extended, maintenance-free monitoring by reducing particulate load on the device while maintaining accuracy. The study addresses four research questions: (1) accuracy compared to gravimetric reference measurements, (2) operational reliability under real-world conditions, (3) temporal PM10 patterns relevant for sampling optimization, and (4) the bias and precision of various sampling strategies in estimating hourly, daily, and long-term PM10 concentrations. Reference measurements were conducted in two cage-free houses over several weeks, while continuous monitoring took place for seven months in a third location. Accuracy was assessed against reference data, and operational reliability was evaluated via regular checkups and parallel sampling. Theoretical analysis of different sampling strategies was based on the continuous dataset. Results indicate a strong correlation with reference methods (R2 = 0.94), though the monitoring device underestimated PM10 concentrations by about 30 %. The monitoring device was capable of operating for significantly longer periods without maintenance under typical cage-free laying hen house conditions than previously reported. Long-term measurements revealed stable temporal patterns in PM10 concentration, which informed the design of optimized sampling strategies. One sampling strategy extended maintenance-free operation by a factor of ten while keeping the uncertainty in hourly PM10 estimates below 9%. These results demonstrate the potential of this combined approach for practical, long-term PM10 monitoring in cage-free laying hen environments.