Transpacific and regional atmospheric transport of anthropogenic semivolatile organic compounds to Cheeka Peak Observatory during the spring of 2002

Abstract

Ambient high‐volume (hi‐vol) air samples were collected between 15 March and 30 May 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic Peninsula, Washington State. This sampling campaign was in conjunction with the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) campaign and the Photochemical Ozone Budget of the Eastern North Pacific Atmosphere 2 (PHOEBA2) experiment. The anthropogenic semivolatile organic compounds (SOCs) measured during this time period included polycyclic aromatic hydrocarbons (PAHs) and various U.S. current‐use and historical‐use pesticides. The total PAH concentration ranged from 0.480 to 4.49 ng/m3, which is comparable to other remote sites throughout the globe. Ten pesticides (hexachlorobenzene, dacthal, chlorothalonil, heptachlor, trans‐nonachlor, cis‐nonachlor, endosulfan I, triallate, trifluralin, and mirex) were also measured, and their concentrations (0.104–57.0 pg/m3) were comparable to other remote sites and less than agricultural areas. Gas‐phase/particle‐phase partitioning was explored, with significant correlation to temperature found with endosulfan I and retene and the possible relationship at CPO of low TSP concentration and the concentration of nonexchangeable compounds in the particle phase. Principal component analysis, as well as a t‐test, showed that there were elevated concentrations of anthropogenic SOCs measured during possible transpacific events on 15–16 March, 27–28 March, and 22–23 April 2002 that were identified using the GEOS‐CHEM model. The potential sources of these compounds at CPO were determined using diagnostic ratios of their concentrations, back trajectories calculated using Hybrid Single‐Particle Lagrangian Integrated Trajectory (HYSPLIT4), local meteorological conditions, and U.S. pesticide use data. Additional data are needed to confirm the sources of anthropogenic SOCs at CPO during regional and transpacific atmospheric transport events.

Global long-range transport and lung cancer risk from polycyclic aromatic hydrocarbons shielded by coatings of organic aerosol

“…5, Bottom). For example, BaP emitted from East Asia travels thousands of miles over the Pacific Ocean, reaching the west coast of the United States, consistent with previous observational studies that identified trans-Pacific atmospheric transport of PAHs (34)(35)(36). Similarly, BaP emitted from Western Europe travels to the east, and BaP emitted from South Africa travels over the South Atlantic Ocean, reaching South America.…”

Atmospheric polycyclic aromatic hydrocarbons in rural and urban areas of northern China

“…High concentrations of PAHs were extensively detected around this country (Bi et al, 2003;Guo et al, 2003;Feng et al, 2006a;Feng et al, 2006b;Li et al, 2006;Luo et al, 2010), inducing elevated lung cancer risk to Chinese population via inhalation exposure (Zhang et al, 2009). PAHs released in China could also be dispersed rapidly through air, and many recent studies have shown that the elevated PAH concentrations are monitored in surrounding countries and continents located downwind of China, including Korea, Japan, and North America, which can be attributed to the outflow of PAHs from China under certain meteorological conditions (Killin et al, 2004;Lee et al, 2006;Tamamura et al, 2007;Lang et al, 2008).…”

Transpacific transport of benzo[a]pyrene emitted from Asia

“…The model results were compared with the observations at six monitoring sites including Changdao, Gosan, Kanazawa, Okinawa, Cheeka Peak Observatory (CPO), and Mount Bachelor Observatory (MBO) during different time periods when observations were actually conducted (Feng et al, 2007;Lee et al, 2006;Tamamura et al, 2007;Primbs et al, 2007;Killin et al, 2004;Primbs et al, 2008). A map of the location of these sites as well as a comparison of their measured concentrations is shown in Fig.…”

“…Many studies dedicated to investigating the episodic nature of transpacific transport indicate stronger transport of pollutants than background level under certain meteorological conditions (Lee et al, 2006;Tamamura et al, 2007;Primbs et al, 2007;Killin et al, 2004;Primbs et al, 2008). Transformation (ITCT 2K2) experiment was conducted over the West Coast of North America, and air masses containing pollutants originating from Asia were measured by aircraft over a region bounded by 32-44 • N, 122-125 • W, and 0-8 km altitude (Allan et al, 2004).…”

“…Surface concentration measurements combined with backward trajectories have shown that semi-volatile organic compounds (SVOCs), including PAHs, can be transported across the Pacific Ocean in about a week under certain meteorological conditions (Primbs et al, 2007;Primbs et al, 2008;Killin et al, 2004). For example, Killinet al (2004) observed significantly elevated concentrations of PAHs and other SVOCs during 15-16 March, 27-28 March and 22-23 April 2002, when backward trajectories passed over Asia, suggesting Asia as the potential source of these compounds.…”