title: Temporal variability of atmospheric particulate matter and chemical composition during a growing season at an agricultural site in northeastern China.
abstract: This study presents the observations of PM10 and PM2.5 concentrations at an agricultural site from April to October 2012 in Dehui city, China. Ambient air was sampled by filter-based samplers and online PM monitors. The filter samples were analyzed to determine the abundance of ionic/inorganic elements, organic carbon (OC) and elemental carbon (EC). The daily PM10 concentrations varied significantly over the monitoring period, with an average of 168±63 (in the range of 52-277)μg/m(3) during the land preparation/planting period (26 April-15 June), 85±65 (36-228)μg/m(3) during the growing season (16 June-25 September), and 207±88 (103-310)μg/m(3) during the harvest period (26 September-31 October). PM2.5 accounted for 44%, 56% and 66% of atmospheric PM10 during these periods, respectively. The PM10 diurnal variation showed a distinct peak from 16:00 to 21:00 (LST) during the growing and harvesting seasons, while a gradual increase throughout the daytime until 17:00 was observed during tilling season. Mineral dust elements (Al, Ca, Fe, and Mg) dominated the PM10 chemical composition during the tilling season; OC, NO3(-), SO4(2-) and NH4(+) during the growing season; and carbonaceous species (i.e., OC and EC) during the harvesting season. Our results indicate that the soil particles emitted by farm tillage and organic matter released from straw burning are the two most significant sources of PM10 emissions contributing to the recurring high pollution events in this region. Therefore, development of agricultural PM inventories from soil tillage and straw burning is prioritized to support air quality modeling.
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 100029, China. Electronic address: chenweiwei@iga.ac.cn.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Chen
authors.affiliation: National Oceanic and Atmospheric Administration (NOAA), MD 20740, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tong
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 100029, China.
authors.forename: Shichun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Beijing Municipal Institute of Labor Protection, Beijing 100054, China.
authors.forename: Mo
authors.initials: M
authors.lastname: Dan
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 100029, China.
authors.forename: Xuelei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 100029, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Agricultural inventory; Burning; Emission factor; Harvest; PM(10); PM(2.5); Tillage