Transboundary movement of polycyclic aromatic hydrocarbons (PAHs) in the Kuroshio Sphere of the western Pacific Ocean (original) (raw)
Related papers
Archives of Environmental Contamination and Toxicology, 2008
Eighteen polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in surface seawater and boundary layer air from the North Pacific toward the Arctic Ocean during the Fourth Chinese National Arctic Research Expedition in the summer of 2010. Atmospheric Σ 18 PAH ranged from 910 to 7400 pg m À3 , with the highest concentrations observed in the coastal regions of East Asia. Correlations of PAHs' partial pressures versus inverse temperature were not significant, indicating the importance of ongoing primary sources on ambient PAH levels in the remote marine atmosphere. The relatively high atmospheric concentrations observed in the most northerly latitudes of the Arctic Ocean suggest the influence of regional sources. For example, higher levels of particle-bound PAHs were observed in the air of the Arctic Ocean than the North Pacific, indicating forest fire and/or within-Arctic sources. Concentrations of PAHs in surface seawater were within a range of 14-760 pg L À1 and generally decreased with increasing latitude. The observed air-sea gas exchange gradients strongly favored net deposition of PAHs along the entire cruise, with increasing deposition with increasing latitude, while the particle-bound dry deposition fluxes (particularly for the high molecular weight PAH) were highest at sample sites close to East Asia. Based on characteristic PAH ratios, atmospheric PAHs originated from the combustion of biomass or coal, while the ratios observed in seawater reflected a mixture of sources. Given the dominance of primary emissions to the atmosphere and the relatively fast removal of PAHs from the water column, then PAHs will continue to load into the surface waters of the remote marine environment via atmospheric deposition.
Environmental Science & Technology, 2015
The relative influences of trans-Pacific and regional atmospheric transport on measured concentrations of polycyclic aromatic hydrocarbons (PAHs), PAH derivatives (nitro-(NPAH) and oxy-(OPAH)), organic carbon (OC), and particulate matter (PM) less than 2.5 μm in diameter (PM 2.5) were investigated in the Pacific Northwest, U.S. in 2010−2011. Ambient high volume PM 2.5 air samples were collected at two sites in the Pacific Northwest: (1.) Mount Bachelor Observatory (MBO) in the Oregon Cascade Range (2763 m above sea level (asl)) and 2.) Confederated Tribes of the Umatilla Indian Reservation (CTUIR) in the Columbia River Gorge (CRG) (954 m asl). At MBO, the 1,8-dinitropyrene concentration was significantly positively correlated with the time a sampled air mass spent over Asia, suggesting that this NPAH may be a good marker for trans-Pacific atmospheric transport. At CTUIR, NO x , CO 2 , and SO 2 emissions from a 585 MW coal fired power plant, in Boardman OR, were found to be significantly positively correlated with PAH, OPAH, NPAH, OC, and PM 2.5 concentrations. By comparing the Boardman Plant operational time frames when the plant was operating to when it was shut down, the plant was found to contribute a large percentage of the measured PAH (67%), NPAH (91%), OPAH (54%), PM 2.5 (39%), and OC (38%) concentrations at CTUIR and the CRG prior to Spring 2011 and likely masked trans-Pacific atmospheric transport events to the CRG. Upgrades installed to the Boardman Plant in the spring of 2011 dramatically reduced the plant's contribution to PAH and OPAH concentrations (by ∼72% and ∼40%, respectively) at CTUIR and the CRG, but not NPAH, PM 2.5 or OC concentrations.
The concentrations and gas-particle partitioning of atmospheric polycyclic aromatic hydrocarbons (PAHs) were intensively measured in the Hengchun Peninsula of southern Taiwan. The concentrations of total PAH (Σ 38 PAH), including gas and particle phases, ranged from 0.85 to 4.40 ng m −3 . No significant differences in the PAH levels and patterns were found between the samples taken at day and at night. The gas phase PAH concentrations were constant year-round, but the highest levels of particle-associated PAHs were found during the northeast monsoon season. Long-range transport and rainfall scavenging mechanisms contributed to the elevated levels in aerosols andΣ 38 PAH concentrations. Results from principal component analysis (PCA) indicated that the major sources of PAHs in this study were vehicular emissions. The back trajectories demonstrated that air mass movement driven by the monsoon system was the main influence on atmospheric PAH profiles and concentrations in the rural region of southern Taiwan. Gas-particle partition coefficients (K p ) of PAHs were well-correlated with sub-cooled liquid vapor pressures (P o L ) and demonstrated significant seasonal variation between the northeast (NE) and the southwest (SW) monsoon seasons. This study sheds light on the role of Asian monsoons regarding the atmospheric transport of PAHs.
Seasonal variation of atmospheric polycyclic aromatic hydrocarbons along the Kaohsiung coast
Journal of Environmental Management, 2011
Thirty-three air samples were collected by high-volume samplers from May 2007 to June 2008 in the coastal area of southwest Taiwan and analyzed for total suspended particulates (TSP) and polycyclic aromatic hydrocarbons (PAHs). Concentrations of TSP and total PAHs ranged from 40.4 to 251 mg m À3 and 1.86e56.4 ng m À3 , respectively. Except for joss paper burning during the religious celebration of Ghost Month, which resulted in the highest concentration of PAHs in the summer of 2007, a seasonal variation in total PAH concentration was observed over this study period, with the highest concentrations in winter and the lowest in summer. Because of the geographical and climatic characteristics of the sampling site, monsoon activities modulate the seasonal variations of PAHs. Diagnostic ratios showed that PAHs in the atmosphere of the Kaohsiung coastal area arose predominantly from vehicle emissions (mainly from diesel exhaust), joss paper burning, and coal/wood combustion. The results of hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicated that the sampling days could be divided into three groups and that the major source identification of PAHs was the same as the identification by diagnostic ratios. In addition, the results of HCA and PCA suggest that the samples collected with a prevailing northerly or northeasterly wind direction contain both local emissions and those from neighboring sources. On the other hand, the cases related to westerly or northwesterly winds indicated that local emission was the major source for the sampling site.
Atmospheric Environment, 2007
Air pollution in rural China has often been ignored, especially for the less developed west China. Atmospheric polycyclic aromatic hydrocarbons (PAHs) were measured monthly at 11 rural sites (5 rural villages and 6 rural fields) together with 7 urban stations in northern China between April 2010 and March 2011. PAH concentrations at rural village sites were similar to those in urban areas and significantly higher than those in rural fields, indicating severe contamination in rural villages. PAH concentrations in the west were similar to those in the more developed North China Plain, and higher than those along the coast. Such a geographical distribution is mainly caused by the differences in residential energy consumption and meteorological conditions, which can explain approximately 48% of the total variation in PAH concentrations. With heavy dependence on biofuel combustion for heating, seasonality in rural areas is more profound than that in urban areas.
Journal of Geophysical Research: Atmospheres, 2012
1] Gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed in air samples taken on a voyage of the Scholar Ship from January 16th to March 14th, 2008. Samples were taken from the Asian marginal seas and the Indian and Atlantic Oceans, providing an opportunity to assess spatial trends and potential sources of atmospheric PAHs over those oceans. The results show that continental sources were still responsible for some high concentrations of PAHs measured over the oceans. The S 15 PAHs in the gaseous phase were elevated on the approach to China and India, while the highest S 15 PAHs in the particulate phase were found at Chennai Harbor and close to Guinea. The high proportion of fluorene in the gas phase over the East and South China Sea could be a marker of coal and coke related combustion emission from Mainland China. The elevated high-molecular-weight PAHs in particles close to Guinea might be related to biomass burning in Africa. These results are consistent with previous PAH emission inventories and highlight the potential impact of continental PAH sources in China, India and Africa on the adjacent marine atmosphere. (2012), The spatial distribution and potential sources of polycyclic aromatic hydrocarbons (PAHs) over the Asian marginal seas and the Indian and
2014
Air samples were collected at four sites from August 2009 to May 2010. Temporal variation of polycyclic aromatic hydrocarbon (PAH) concentrations showed the highest concentration in November and the lowest in May, except for one case attributable to a specific meteorological event, a typhoon, which resulted in a dramatic increase in PAHs concentrations. PAH compositional pattern, 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.
Aerosol and Air Quality Research
This study investigated atmospheric particulate matter (PM) with an aerodynamic diameter of < 2.5 µm (PM 2.5) observed at the Prince of Songkla University (Phuket Campus) in southern Thailand. All samples (n = 75) were collected using MiniVol™ portable air samplers from March 2017 to February 2018. Carbonaceous aerosol compositions, i.e., organic carbon (OC) and elemental carbon (EC), water-soluble ionic species (WSIS), and polycyclic aromatic hydrocarbons (PAHs) in the PM 2.5 samples were identified and quantified. We found that the average PM 2.5 concentration was 42.26 ± 13.45 µg m-3 , while the average concentrations of OC and EC were 3.05 ± 1.70 and 0.63 ± 0.58 µg m-3 , respectively. The OC/EC ratio was in the range of 2.69-16.9 (mean: 6.05 ± 2.70), and the average concentration of 10 selected ions was 6.91 ± 3.54 µg m-3. The average concentration of SO 4 2was the highest throughout the entire study period (2.33 ± 1.73 µg m-3); the average contribution of SO 4 2to the major ionic components was 34%. Surprisingly, the average concentrations of NO 3and NH 4 + were relatively low. The mean ratio of [NO 3-]/[SO 4 2-] was 0.33 ± 0.24. Strong positive correlation was found between K + and both OC and EC (r = 0.90 and r = 0.93, respectively). It is also precious to highlight that biomass burning (BB) is the major source of OC, EC and K + , which multiple studies have confirmed that the role of K + as a biomass marker. Results showed that BB episodes might play a major role in producing the observed high levels of OC. The relatively high abundance of both B[g,h,i]P and Ind suggests that motor vehicles, petroleum/oil combustion, and industrial waste burning are the primary emission sources of PAHs in the ambient air of Phuket. Interestingly, principal component analysis (PCA) indicated that vehicular exhausts are the main source of carbonaceous aerosol compositions found in the ambient air of Phuket, whereas the contributions of biomass burning, diesel emissions, sea salt aerosols and industrial emissions were also important.