Analysis of characteristics and influencing factors of fine particulate matters and submicron particulate matters in printing shop / 中华预防医学杂志

ABSTRACT

Objective@#To analyze the physical characteristics of fine particulate matters (PM2.5) and submicron particulate matters (PM1), and investigate the factors influencing the emission peak of printer particles.@*Methods@#A 12-hour particle concentration monitoring for PM2.5 and PM1 was conducted in a printing shop on January 5th, 2018. PM2.5 in the air was analyzed after the monitoring process to figure out morphological characteristics and element composition of printer particles. Besides, experiments were carried out in an enclosed space to detect the number concentration peaks of PM1 during every printing process. Influencing factors investigated in this study were printer types, toner coverages and interval time between different printing processes.@*Results@#The 12-hour particles concentration monitoring showed that the number concentration of PM1 and the mass concentration of PM2.5 were 7.510×104 pt/cm3 and 96.85 μg/m3. The diameter of most PM2.5 was less than 100 nm, with a fractal dimension of 2.591. Most PM2.5 appeared as regular spheres with typical agglomeration phenomenon, while some were in rhabditiform or irregular shapes. Element analysis showed that PM2.5 was mainly composed of C, O, Si, Ca, with less metallic element. The PM1 emission peak values of three printers were 3.60×104, 3.43×104, 0.31×104 pt/cm3, respectively and the difference was not statistically significant (χ2=5.42, P>0.05). When the page coverage rate was 0%, 2.5%, 5%, 10%, 20% and 50%, the PM1 emission peak value of printer A was 6.74×104, 4.62×104, 3.82×104, 2.82×104, 1.00×104 and 1.08×104 pt/cm3, and the difference was also not statistically significant (χ2=7.01, P>0.05). The natural logarithm of PM1 emission peak value in printing work was associated with the resting time before printing and the change value of heating roller temperature (r value was 0.83 and 0.89, respectively, all P values<0.05).@*Conclusion@#PM2.5 and PM1 in the printing shop stayed at a high level. Particles appeared as various shapes and element compositions were complex. The temperature change of heating roller was one of most important factors that lead to the increased number concentration peak of PM1.