ORIGINAL PAPER Persistent organic pollutants in tropical coastal and offshore environment: part A—atmospheric polycyclic aromatic hydrocarbons I.-C. Lai • C.-L. Lee • F.-C. Ko • J.-C. Lin • H.-C. Huang Received: 22 July 2013 / Revised: 13 November 2013 / Accepted: 14 December 2013 / Published online: 9 January 2014 Ó Islamic Azad University (IAU) 2013 Abstract Air samples were collected at four sites from August 2009 to May 2010. Temporal variation of polycy- clic aromatic hydrocarbon (PAH) concentrations showed the highest concentration in November and the lowest in May, except for one case attributable to a specific meteo- rological event, a typhoon, which resulted in a dramatic increase in PAHs concentrations. PAH compositional pat- tern, diagnostic ratios, hierarchical cluster analysis, and principal component analysis indicated that the major sources of PAHs in the Gaoping coastal area were local vehicle emissions, stationary sources, and coal/wood combustion. In addition, the distinct compositional patterns at each sampling site suggested that sources of PAHs varied with sampling periods. Back trajectory analysis indicated that transport pathway and moving speed of air parcels were two important factors that influence temporal and spatial variation of PAH concentrations. Air parcel pathways and PAH compositional patterns also indicated that PAHs observed at an offshore island (Liu-Chiu Isle) in November were affected by sources in the southwest coastal area of Taiwan. The data set of PAH concentrations built in this study provides useful information to estimate air–water exchange behavior of PAHs and to investigate the fate of PAHs in the Gaoping coastal area. Keywords Seasonal variation Á Source identification Á Back trajectory analysis Á Air parcel pathway Introduction Over the past several decades, persistent organic pollutants (POPs) have been intensively studied to understand their fate and behavior. POPs are a group of organic chemicals with semi-volatile, bio-accumulative, toxic, and persistent characteristics (UN/ECE/EB.AIR/1998/1). Their sources are usually anthropogenic activities, such as industrial, agricultural, transportation, and combustion processes. Due to their bioaccumulation and potent toxic characteristics, these chemical compounds have adverse effects on human health and the environment (Safe and Hutzinger 1984; Safe 1990; Vreugdenhil et al. 2002). Unlike most other air pollutants, POPs are capable of permanent retention in the environment; they can be distributed into the environment through several routes (e.g., deposition or air–water exchange into aquatic environments and sink to the soil environment) (Agrell et al. 2002; Castro-Jime ´nez et al. 2011; Jurado et al. 2004, 2005). In addition, physico- chemical properties of POPs may favor long-range trans- port through atmospheric circulation (Halsall et al. 2001; Halse et al. 2011; Wania and MacKay 1996). These char- acteristics have resulted in an international protocol to Electronic supplementary material The online version of this article (doi:10.1007/s13762-013-0482-y) contains supplementary material, which is available to authorized users. I.-C. Lai Á C.-L. Lee (&) Á J.-C. Lin Á H.-C. Huang Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan e-mail: linnohc@fac.nsysu.edu.tw C.-L. Lee Kuroshio Research Group, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan C.-L. Lee Center for Emerging Contaminants Research, National Sun Yat-sen University, Kaohsiung, Taiwan F.-C. Ko Institute of Marine Biodiversity and Evolutionary Biology, National Dong-Hwa University, Pingtung, Taiwan 123 Int. J. Environ. Sci. Technol. (2015) 12:1075–1086 DOI 10.1007/s13762-013-0482-y