Marine aerosols (MA) can be influenced by sea ice concentration, potentially playing a pivotal role in the formation of cloud condensation nuclei and exerting an impact on regional climate. In this study, a high-resolution aerosol observation system was employed to measure the concentration and size of aerosols in the floating ice region and seawater region of the Arctic Ocean during the 8th and 9th Chinese Arctic Expedition Research Cruise. The identification of aerosol sources was conducted using a modified positive definite matrix factorization method and a backward air mass trajectory model. Two types of MA including the sea-salt aerosol (SSA) and the marine biogenic aerosol (BA) were identified and their concentrations were calculated. Then the physical-chemical characteristics of MA in the floating ice region and seawater region were compared under normalized conditions (-2.5 °C < T < -0.1 °C; 5.80 m/s < WS < 10.95 m/s) to discern the impact of sea ice. A unimodal distribution was observed for MA number concentration with a dominant peak ranging from 0.5 μm to 1.0 μm in size range. The findings revealed that the presence of sea ice cover led to a significant reduction of 52.2 % in the number concentration of SSA, while exerting minimal influence on its composition. BA number concentration in the floating ice region was 33.3 % higher than that in the seawater region. Strong winds (wind speed >6.5 m/s) transported organic matter and nutrients entrapped in sea ice into the atmosphere, leading to an increase in BA concentration. However, the presence of sea ice cover hampered the exchange of biogenic gases between the ocean and air, resulting in a reduction of secondary BA formation. Our study elucidates the correlation between MA release and sea ice coverage in the Arctic Ocean, thereby establishing a theoretical foundation for climate prediction models.

Atmospheric particulate samples collected from Pingtan Island in Fujian province were analyzed for 20 organochlorine pesticides (OCPs) with the aims of elucidating the contamination levels and their influence factors, and providing more comprehensive and fundamental data for the risk assessment of OCPs in this coastal area. The concentration of total OCPs ranged from ND (not detected) to 27.25 pg m–3 (an average of 4.30 ± 4.07 pg m–3) and ND to 13.16 pg m–3 (an average of 3.11 ± 2.54 pg m–3) in 2006 and 2007 respectively, and the level are obviously lower than urban, industrial, suburban, and the similar research areas in the coastal areas of Europe. HCH (Hexachlorocyclohexane) and DDT (Dichlorodiphenyltrichloroethane) were the predominant contaminants, followed by Methoxychlor and Endrin, while the levels of Chlordane, Endosulfan, Aldrin and Dieldrin was relatively lower. Obvious seasonal variations in OCP levels correlate significantly with total particulate levels; higher concentrations of most OCP compounds appeared in winter, whereas lower concentrations appeared in summer. The distribution pattern of the level of most OCP compounds might be directly or indirectly influenced by meteorological conditions, and TOC (total organic carbon) is an important factor influencing the persistence of these OCPs in atmospheric particulates. The source of atmospheric particulates was traced by stable carbon isotopes, which indicate that the increased levels of OCPs in winter and spring influenced by the source of polluted air mass during the “heating season” of Northern China. The cancer risk probability was evaluated based on the residual levels of OCPs, and the results show that dermal contact was the primary pathway affecting human health, and the effect of OCP residuals in atmospheric particulates of the coastal area could not be neglected.

Atmospheric particulate samples were collected during three typhoons in 2006 (Chanchu, Bilis, and Kaemi) from Dongshan and Pingtan Islands along the coastal areas of Fujian Province and were analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The observations were divided into three periods, namely, pre-typhoon, typhoon, and post-typhoon, to analyze the variations in POP concentrations. The results showed that the PCB and OCP concentrations had daily variations during the pre-typhoon period, while different variation trends were observed during the typhoon periods. The concentrations of those contaminants increased dramatically during typhoon Chanchu (the total concentrations of PCBs and OCPs increased 25 and 24 times, respectively), whereas those values decreased slightly during the typhoon Bilis and Kaemi. However, POPs levels all decreased noticeably during the three post-typhoon periods due to heavy rainfall caused by the typhoons. Observations of an ensemble of factors, including the typhoon migration routes, landfall season, air mass origins and meteorological conditions, and the typhoon migration route was the dominant factor to cause high levels of POPs during the typhoon Chanchu period. Toxicity assessment indicated that the effect of PCB and OCP during the typhoon period should be a concern, which could pose a high potential health risk to organisms.

通过采集台湾海峡西岸厦门岛秋、冬两季的近海大气颗粒物样品,分析20种有机氯农药(OCPs)的污染特征及可能来源,并估算OCPs干沉降入海通量.结果 显示,厦门岛大气颗粒物中OCPs主要为DDTs、HCHs和Methoxychlor.季节变化上,受中国北方陆地污染气团来源的影响,冬季OCPs各化合物的浓度高于秋季.2006至2008年,OCPs浓度呈上升趋势,可能受到该时期内厦门灰霾日数明显增加导致大气总悬浮颗粒物含量增长的影响.与国内主要城市区域相比,OCPs浓度处于较低水平,与背景区域的浓度水平相当.通过分子标志物示踪污染物来源显示,DDTs、氯丹和硫丹主要为历史残留,而HCHs主要受到工业HCHs污染的影响.秋季和冬季,OCPs的大气干沉降通量分别为3.49 ng/(m2·d)和9.25 ng/(m2·d),按照台湾海峡海域覆盖面积(63000 km2)估算,秋季和冬季大气颗粒物中OCPs通过于沉降入海通量分别为20.03 kg和52.45 kg.

To explore the polychlorinated biphenyl (PCB) pollution characteristics of atmospheric particles, influential factors, and dry deposition fluxes, 28 PCB congeners were examined over a 2-year period in the environment of an isolated island in Fujian Province. In 2006 and 2007, PCB concentrations ranged from 1.12 to 87.32 pg m−3 and ND (not detected) to 44.93 pg m−3, respectively, and were predominantly highly-chlorinated PCBs. The levels were much lower than those from industrial, urban, and rural areas, but slightly higher than those found in coastal areas of Europe and in the ocean. Obvious seasonal variations were found in the PCB levels, with high levels appearing in the winter, whereas low levels appeared in the summer, which indicated a significant positive correlation with the atmospheric particle mass level. The distribution pattern of the PCB concentration was largely affected by the meteorological conditions and total organic carbon (TOC) levels. Moreover, air mass originating from Northern China may be responsible for the higher PCB levels over Pingtan Island during the winter, and tracing the source of atmospheric particles by the stable carbon isotope suggested that the PBC levels may be influenced by coal combustion during the “heating season” of Northern China. The total dry deposition flux of the 28 PCBs on Pingtan Island was 3.94 ng m−2 d−1 and 2.94 ng m−2 d−1 in 2006 and 2007, respectively, and the average yearly input to the adjacent waters was 7531.2 g y−1.

Atmospheric particulate matter samples were collected at Pingtan Island over the western Taiwan Strait region from January to April,2006.Polychlorinated biphenyls (PCBs)of the samples were analyzed by Gas chro-matography-Electron capture detector (GC-ECD),and then the concentrations,compositions,possible sources of PCBs and dioxin-like polychlorinated biphenyls (DL-PCBs)were studied.Results showed that the mass concentra-tions of PCBs in the Pingtan Island aerosol samples varied from 0.223 pg/m3 to 21.658 pg/m3 ,with an average of 4.820 pg/m3 .PCB138 and PCB189 were the major homolog monomers of the 28 analyzed PCBs’homolog mono-mers.Higher molecular weight PCB congeners were dominated and the average ratios of concentrations for hexa-and hepta-CBs to the total PCBs concentrations were 44.5% and 32.2% respectively.The toxic equivalent quanti-ties (TEQ)of 11 DL-PCBs were in the range of 0.008 ~215.576 fg/m3 ,while PCB126,PCB 123 and PCB 189 were the dominant contributors to the TEQ.Concentrations of CPCBs-27 and CDL-PCBs-11 were higher in winter (January and February),while a little lower in spring (March and April).Backward air mass trajectory analysis suggested that heating and industrial emissions of northern urban areas in China may contribute some PCBs pollution to Ping-tan Island in winter and spring.