Seasonal Variation of Visibility and the Relationship with Mass Concentration and Total Carbon of PM10 in Shijiazhuang, China

Shijiazhuang has been in visibility impairment situation for many years but with less studied. In this research, we collected the meteorology data and sampled PM₁₀ to measure the mass concentration and total carbon content, in odor to discuss the possible relationship with visibility. The results show that the annually average visibility declines to 10.2-12.7km and monthly average visibility presents seasonal variations with the highest in spring and lowest in winter when the visibility declined abruptly from 2004 to 2006. The relative humidity is negative correlative to the visibility with r -0.694 in winter. Both the mass concentration and total carbon content of PM₁₀ are negative to the visibility to the extent that the better visibilities (over 20km) correspond to the PM₁₀ with mass concentration below 0.10mg/m³, and total carbon content below 0.02mg/m³; and the worse visibility (less than 10km), to the mass concentration over 0.45mg/m³ and total carbon content over 0.07mg/m³. And controlling the carbon particulate emission is more effective for the visibility improvement in Shijiazhuang.