title: Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution.
abstract: Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.
authors: Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, 30 Kajung-dong, Yusung-gu, Daejeon, 305-350, Korea.
authors: Pyeong-Koo
authors: PK
authors: Lee
authors: Korea CO2 Storage Environmental Management Research Center, Korea University, Seoul, 02841, Korea.
authors: Soonyoung
authors: S
authors: Yu
authors: Advanced Analysis Center, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 136-791, Korea.
authors: Hye Jung
authors: HJ
authors: Chang
authors: Advanced Analysis Center, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 136-791, Korea.
authors: Hye Young
authors: HY
authors: Cho
authors: Department of soil and Groundwater, Korea Environment Corporation, 42 Hwangyeong-Ro, Seo-gu, Incheon 404-708, Korea.
authors: Min-Ju
authors: MJ
authors: Kang
authors: Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, 30 Kajung-dong, Yusung-gu, Daejeon, 305-350, Korea.
authors: Byung-Gon
authors: BG
authors: Chae
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002840:Chromates / Q000032:analysis*; D002857:Chromium / Q000032:analysis; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D004787:Environmental Pollution / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D046529:Microscopy, Electron, Transmission; D052638:Particulate Matter / Q000032:analysis*; D056910:Republic of Korea; D013052:Spectrometry, X-Ray Emission
chemical_list: D000393:Air Pollutants; D002840:Chromates; D004391:Dust; D052638:Particulate Matter; D002857:Chromium; D007854:Lead; C031895:lead chromate