# Advanced Strategies for Mitigating Particulate Matter Generations in Poultry Houses
## 3 Factors Affecting Dust Generations
### Effect of Lighting and Seasonal Variations on PM Levels  
During the daytime, increased activities of birds lead to a higher PM concentration than the nighttime [60]. The concentration of PM\({}_{2.5}\), PM\({}_{10}\), and TSP were 151, 108, and 136% higher (\(p<0.05\)) during the daytime (lights on) than at nighttime. During the daytime, birds were most active, ventilation rates were highest, and emissions rose. However, the ratio of PM\({}_{2.5}\) and PM\({}_{10}\) decreases at night because of low bird activities and the settling down of PM\({}_{10}\) concentration [37].  
The emission of PM is seasonally dependent and varies over time (Table 4) [37; 38]. PM concentration increases in the winter compared to fall, spring, and summer [4; 37; 38; 50; 61]. According to [PERSON] et al. (2011), the concentration of PM\({}_{10}\) was found to be lower during summer relative to winter due to higher air temperature and ventilation rates [50]. In addition, hens tend to move less if there are under heat stress in summer because the higher indoor air temperature may cause stagger, stupor, and reduced activities, and thus result in lower dust generation from the litter, while the cold season increases layers' activities, thus generating higher PM from the poultry house litter floor [62]. Besides animal activities, house ventilation and litter moisture are critical for PM generations. Therefore, the total poultry house PM emissions could be higher in summer than in winter because of increased house ventilation and drier litter conditions [30].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Bedding Material** & **Source** & **PM Sizes** & \begin{tabular}{c} **PM Emission** \\ **(mg/m3)** \\ \end{tabular} & **References** \\ \hline \hline Cornstalk chip & Broiler & TSP & 6.5 & [58] \\ \hline Sugarcane top chips & Broiler & TSP & 6.8 & [58] \\ \hline Wood shaving & Laying hens & TSP & 2.3 & [56] \\ \hline Wood shaving & Broiler & \begin{tabular}{c} PM\({}_{2.5}\)* \\ PM\({}_{10}\)* \\ \end{tabular} & \begin{tabular}{c} 1.05 \\ 20.3 \\ \end{tabular} & [55] \\ \hline Sawdust & Dairy farm & TSP & 0.51 & [59] \\ \hline Wheat straw & Broiler & TSP & 6.9 & [58] \\ \hline Rapeseed straw & Broiler & \begin{tabular}{c} PM\({}_{2.5}\)* \\ PM\({}_{10}\)* \\ \end{tabular} & \begin{tabular}{c} 0.98 \\ 20.6 \\ \end{tabular} & [55] \\ \hline Rapeseed straw & Broiler & \begin{tabular}{c} PM\({}_{2.5}\)* \\ PM\({}_{10}\)* \\ \end{tabular} & 0.97 and 20.5 & [55] \\ \hline Clover straw & Broiler & TSP & 6.7 & [58] \\ \hline Chopped straw & Laying hens & TSP & 2.1 & [56] \\ \hline Straw & Dairy farm & TSP & 0.53 & [59] \\ \hline Chopped palm spines & Broiler & TSP & 6.5 & [58] \\ \hline Corn ear husks & Broiler & TSP & 6.8 & [58] \\ \hline Silage maize & Broiler & \begin{tabular}{c} PM\({}_{2.5}\)* \\ PM\({}_{10}\)* \\ \end{tabular} & \
\begin{tabular}{c} 0.85 \\ 21.0 \\ \end{tabular} &
\begin{tabular}{c} [55] \\ [55] \\ \end{tabular} \\ \hline Chopped paper & Laying hens & TSP & 2.6 & [56] \\ \hline Peat & Laying hens & TSP & 1.7 & [56] \\ \hline Compost & Dairy farm & TSP & 1.38 & [59] \\ \hline Clay pellets & Laying hens & TSP & 1.8 & [56] \\ \hline Gravel & Laying hens & TSP & 4.7 & [56] \\ \hline \hline \end{tabular}  
* g year\({}^{-1}\)ap\({}^{-1}\) (ap = animal place, inoccupation of 19%).  
\end{table}
Table 3: Particulate matter emission due to different bedding materials used in the poultry housing system.