Boron Isotopic Analysis of Representative Atmospheric Aerosols Derived From Long-Range Transported/Local Emission on an Islet Offshore NE Taiwan Yen-Po Lin 1 , Chen-Feng You 1 *, Tsung-Yu Kao 1 , Chuan-Hsiung Chung 1 and Chung-Chieh Gary Hung 2 1 Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan, 2 Institute of Archaeology, National Cheng Kung University, Tainan, Taiwan To identify pollutant origins and their potential sources from either long-range transported (LRT) or local emissions, the Boron (B) concentrations and the B isotopic compositions (δ 11 B) in the water-soluble fraction of aerosols were determined. These aerosols were collected from an islet offshore in northeastern Taiwan, Peng Chia Yu (PCY), a non- residential islet, from January 1998 to March 2000. This islet may be influenced by various pollutants or chemical transport during monsoon periods, but suffers minimal human perturbation locally. The B in the specimens falls to 0.3–1.63 ng m −3 during the SW monsoon seasons when compared to 0.46–2.56 ng m −3 in the NE monsoon. However, the δ 11 B results show no clear variations in both monsoon seasons (10.7–24.3‰), regardless of differences in air mass origin. A two end-member mixing scenario is proposed to explain our observations using the obtained δ 11 B and 1/[B] results. The ocean endmember is characterized by high 1/[B] and high δ 11 B; while other endmember is from continental endmember or anthropogenic contributions that are characterized by of 1/[B] and lowδ 11 B(δ 11 B < 10‰). Based on these chemical and isotopic results, we found aerosol emissions in northern Taiwan are characterized as low B with nearly constant δ 11 B, when compared with long-range transported continental endmembers derived from nearby regions. This study provides preliminary B and δ 11 B levels in aerosols derived from LRT/local emissions and discusses potential monsoonal effects on aerosols offshore of NE Taiwan. Keywords: aerosol, boron isotopes, long-range transported, local emission, tracers INTRODUCTION Air pollution in Taiwan derives primarily from local emissions and long-range transported (LRT; Lin, 2001; Hsu et al., 2006). Identifying the sources of pollutants is the first step in developing greater air quality control program in the environment. The emissions from local sources are generated mainly by the domestic combustion of fossil fuels. In Southeast Asia, aerosol transportation from China has rapidly increased over the last few decades, because of a marked increase in coal consumption (Fogg and Duce, 1985; Park and Schlesinger, 2002; Zhao and Liu, 2010). The sources of Edited by: Maciej Górka, University of Wrocl aw, Poland Reviewed by: Ashwini Kumar, Council of Scientific and Industrial Research (CSIR), India Andrius Garbaras, Center for Physical Sciences And Technology (CPST), Lithuania Yangmei Zhang, Chinese Academy of Meteorological Sciences, China *Correspondence: Chen-Feng You cfy20@mail.ncku.edu.tw Specialty section: This article was submitted to Toxicology, Pollution and the Environment, a section of the journal Frontiers in Environmental Science Received: 20 April 2021 Accepted: 10 June 2021 Published: 23 June 2021 Citation: Lin Y-P, You C-F, Kao T-Y, Chung C-H and Hung C-CG (2021) Boron Isotopic Analysis of Representative Atmospheric Aerosols Derived From Long-Range Transported/Local Emission on an Islet Offshore NE Taiwan. Front. Environ. Sci. 9:697844. doi: 10.3389/fenvs.2021.697844 Frontiers in Environmental Science | www.frontiersin.org June 2021 | Volume 9 | Article 697844 1 ORIGINAL RESEARCH published: 23 June 2021 doi: 10.3389/fenvs.2021.697844