Abstract: In order to better understand the chemical components and their variations of background aerosols in the North China Plain, sixty-four PM10 samples were collected on the top of Mount Tai from June 2010 to July 2011. The mass concentrations and seasonal variations of PM10 as well as its nine water soluble ions, organic carbon (OC) and elemental carbon (EC) have been analyzed. The correlation analysis of various chemical components has also been performed. The annual average mass concentration of PM10 is 68.4 mg/m³, and inorganic salts accounts for 64.8% in PM10, while carbon aerosol accounts for 17.4%. The mass concentration of inorganic salt increases gradually from spring, reaches its peak in summer, then decreases in autumn and comes to the lowest in winter. The mass concentration of OC increases from spring to autumn and reaches the minima in winter. Similar pattern has been found in the mass concentration of EC; however, the EC concentrations of summer and autumn are similar. The ratio of secondary organic carbon (SOC) to OC is above 50% for all seasons with an annual average of 58.5%. Back trajectory analysis shows that when Mount Tai is mainly influenced by air masses from the southern area and megacities, mass concentrations of PM10 and its components are high; while it is mainly influenced by air masses from Northwest China through long distance transportation, the mass concentrations of PM10 and its components are much lower.

Key words: Calibri", ,", sans-serif", font-size: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-theme-font: minor-latin, mso-fareast-font-family: 宋体, mso-fareast-theme-font: minor-fareast, mso-hansi-theme-font: minor-latin, mso-bidi-font-family: 'Times New Roman', mso-bidi-theme-font: minor-bidi, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA" lang="EN-US">PM10, water soluble ions of inorganic salt, organic carbon, elemental carbon, Mount Tai