Could nutrition status predict fatigue one week before in patients with nasopharynx cancer undergoing radiotherapy?

BACKGROUND: Patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy experience significant fatigue, which is frequently underestimated due to the lack of objective indicators for its evaluation. This study aimed to explore the longitudinal association between fatigue and nutrition status 1 week in advance. METHODS: From January 2021 to June 2022, a total of 105 NPC patients who received intensity-modulated radiation therapy were enrolled in the observational longitudinal study. The significant outcomes, including the Piper Fatigue Scale-12 (PFS-12), the Scored Patient-Generated Subjective Global Assessment (PG-SGA), four body composition indices, and the Hospital Anxiety and Depression Scale (HADS), were assessed weekly from pre-treatment until the completion of radiotherapy (T0-T7) to explore their relationship. RESULTS: The trajectories of PFS-12 and all dimensions for 105 participants reached a peak during the fifth week. Sensory fatigue consistently received the highest scores (T0 = 1.60 ± 2.20, T5 = 6.15 ± 1.57), whereas behavior fatigue exhibited the fastest increase over time (T0 = 1.11 ± 1.86, T5 = 5.47 ± 1.70). Higher PG-SGA scores were found to be weakly explainable for aggravating fatigue (ß = 0.02 ~ 0.04). Unlike generalized additive mixed models, marginal structural models (MSM) produced larger effect values (ß = 0.12 ~ 0.21). Additionally, body composition indices showed weakly negative relationships with fatigue in MSMs one week in advance. CONCLUSIONS: The PG-SGA may be a more accurate predictor of future-week fatigue than individual body composition indicators, particularly when HADS is controlled for as a time-dependent confounder.

Spatiotemporal distribution and particle-water partitioning of polycyclic aromatic hydrocarbons in Bohai Sea, China.

The Bohai Sea is one of the most polluted marine areas in China with polycyclic aromatic hydrocarbons (PAHs) due to its unique hydrological and geographical environment. To investigate differences in PAH concentrations, composition, and particle-water partitioning before and after the rainy reason, water samples were collected during two surveying voyages covering most of the area of the Bohai Sea. Total and dissolved PAH concentrations were higher during the June voyage (total PAHs: 32.29 ± 15.18 ng/L, dissolved PAHs: 31.25 ± 15.26 ng/L) than the August voyage (total PAHs: 15.98 ± 6.39 ng/L, dissolved PAHs: 11.21 ± 5.59 ng/L). The opposite trend was observed for particulate PAHs (June: 1.04 ± 1.01 ng/L, August: 4.78 ± 2.96 ng/L). Among particulate PAHs, an unusually high proportion (65.07%) of low-molecular-weight (LMW) PAHs was observed during the August voyage, which was significantly higher than the proportion during the June voyage (21.86%). This high proportion was inconsistent with the general distribution of PAHs in the aquatic environment according to their physicochemical properties. The excess LMW PAHs adsorbed on suspended particulate matter arose mainly from soil affected by the petrochemical industry of the Bohai Economic Rim, and were carried with particles on runoff into the Bohai Sea during the rainy season. An estimated 5.49 t of LMW PAHs transitioned from the particulate phase to the dissolved phase during the rainy season. This transfer of LMW PAHs from coastal soil to the water column may be an important source of PAHs in the Bohai Sea.

Investigating the presence of organophosphate esters in sediments from a typical fishing port agglomeration in Dalian, North China.

The presence of 14 organophosphate esters (OPEs) in surface sediments from a typical fishing port agglomeration in Dalian, North China was investigated for the first time. Tris(2-ethylhexyl) phosphate (TEHP), triphenylphosphine oxide (TPPO), and tris(2-chloroethyl) phosphate (TCEP) dominated 12 detectable OPEs (∑OPEs), with concentrations ranging widely from 0.56 to 352 ng/g (dry weight basis). The ∑OPE levels in sediments varied significantly across fishing harbors of various grades, and within the same grade, highlighting uneven distribution of OPE sources and inputs to harbors. The first- and second-class fishing harbors had higher geometric mean of ∑OPE contents compared to center and natural harbors, reflecting higher OPE pollution in these areas. Although there were significant correlations among the OPE congeners with high detection frequencies, the composition patterns of sediment OPEs varied considerably among fishing ports. The sediments in the center and first-class harbors had higher abundance of non-chlorinated OPEs (non-Cl-OPEs), suggesting heterogeneity in source strength and pollution characteristics of Cl- and non-Cl-OPEs in fishing ports. The distribution of OPEs in sediments was weakly associated with sediment organic carbon, but not socioeconomic variables, indicating complex controlling factors of their distributions in port sediments. The ecological risks of sediment OPEs were evaluated, and while OPE accumulations ranged broadly (7-684 ng/cm2), exposure hazards were negligible. The sediments in first- and second-class fishing harbors, which had greater OPE accumulation, were identified as reservoirs of OPEs in port aquatic environments.

Occurrence, source, and transfer fluxes of organophosphate esters in the South Pacific and Fildes Peninsula, Antarctic.

Concentrations of 11 organophosphate esters (OPEs) were investigated in surface water and atmosphere samples collected from the South Pacific and Fildes Peninsula. TEHP and TCEP were the dominant OPEs in South Pacific dissolved water, with concentration range of nd-106.13 ng/L and 1.06-28.97 ng/L, respectively. The total concentration of ∑10OPEs in the South Pacific atmosphere was higher than that in Fildes Peninsula, ranging from 216.78 to 2033.97 pg/m3 and 161.83 pg/m3, respectively. TCEP and TCPP were the most dominant OPEs in the South Pacific atmosphere, while TPhP was the most prevalent in the Fildes Peninsula. The air-water exchange flux of ∑10OPEs at the South Pacific was 0.04-3.56 ng/m2/day, with a transmission direction of evaporation totally determined by TiBP and TnBP. The atmospheric dry deposition dominated the transport direction of OPEs between air and water, with an flux of Σ10OPEs at 10.28-213.62 ng/m2/day (mean: 85.2 ng/m2/day). The current transport flux of OPEs through the Tasman Sea to the ACC (2.65 × 104 kg/day) was significantly higher than the dry deposition flux over the Tasman Sea(493.55 kg/day), indicating the Tasman Sea's importance as a transport pathway for OPEs from low latitude areas to the South Pacific. Principal component analysis and air mass back-trajectory analysis provided evidence of terrestrial inputs from human activities that have impacted the environment in the South Pacific and the Antarctic.

Effects of Multimodal Exercise on Health-related Physical Fitness and Quality of Life in Patients with Nasopharyngeal Carcinoma during Radiotherapy.

BACKGROUND: The health-related physical fitness of patients with nasopharyngeal carcinoma can decrease significantly during radiotherapy, which can adversely affect their quality of life. AIM: This study was designed to evaluate the potential influence of a multimodal exercise program on the health-related physical fitness and quality of life of patients with nasopharyngeal carcinoma during radiotherapy. METHODS: Forty patients with nasopharyngeal carcinoma undergoing radiotherapy in the First Affiliated Hospital of Fujian Medical University from May to November 2019 were included. The participants in the control group (N=20) received routine nursing, while those in the intervention group (N=20) were also subjected to the multimodal exercise program during radiotherapy. RESULTS: The multimodal exercise program had a positive effect on participants. The step test index in the intervention group was significantly higher as compared to the control group (p < .05). The participants were subjected to 5 times slow speed (60°/s) and 10 times fast (180°/s) speed, and function of some extensor and flexor muscles of the elbow, shoulder, and knee joints in the intervention group was markedly improved (p < .05). In the intervention group, the grip strength of the right hand was observed to be significantly improved (p < .01). Furthermore, the upper limb scratch dorsal test of intervention group was significantly better than that of the control group (p < .05). The scores of physical, emotional, and social functions in the intervention group were found to be significantly higher as compared to the control group (p < .05). CONCLUSIONS: The multimodal exercise program significantly improved the health-related physical fitness and life quality of the patients with nasopharyngeal carcinoma during radiotherapy, though its long-term effects remain to be further analyzed.

Polycyclic aromatic hydrocarbons in Fildes Peninsula, maritime Antarctica: Effects of human disturbance.

This study provides the first data on the distribution, sources, and transport dynamics of polycyclic aromatic hydrocarbons (PAHs) in Fildes Peninsula, Antarctica via summertime analyses of lakes, seawater, snow, and air in 2013. Relatively high PAH levels and similar composition profiles (dominance of two- and three-ring PAHs) in the investigated marine and terrestrial environmental matrices were found, indicating substantial primary emissions of petrogenic PAHs. This result was corroborated by nonequilibrium partitioning of atmospheric PAHs caused by release of anthropically-derived lighter PAHs and air mass movement trajectories mainly originated from the Antarctic marginal seas. Notable geographical disparities of PAH pollution in the various types of samples consistently suggested impacts of station-related activities, rather than long-range atmospheric transport, on PAHs in Fildes Peninsula. The lack for temperature dependence for gas-phase concentrations and various molecular diagnostic ratios of atmospheric PAHs demonstrated that the impact of local anthropogenic inputs on air PAH variability supersedes the re-emission effect. The derived air-water and air-snow exchanges of PAHs in this remote region indicated a disequilibrium state, partially associated with intense local emissions of PAHs. PAH outgassing from, and absorption into, lake and marine waters were both observed, probably due to differences in anthropogenic influences among sites, while the net deposition of gaseous PAHs into snow prevailed. The results of this study shed lights on the major importance of native anthropogenic sources in the footprint and fate of PAHs in the Fildes Peninsula, which merits further monitoring.

Deposition records of persistent organic pollutants and black carbon in dated sediment cores from China marginal seas: Implications for terrestrial sources and transport processes.

Black carbon (BC) and persistent organic pollutants (POPs) were analyzed from three sediment cores collected offshore in the East China Marginal Seas. The results showed steadily increasing or stable BC concentrations and fluxes. By contrast, time trends of POPs fluxes were consistent with historical records of commercial production and use in China. Although the POP inventories decreased significantly with increase in offshore distance, the relatively consistent trends for individual POPs in different sea areas confirmed that the main sources are derived from mainland China and that atmospheric input was an important contribution. POPs inventories decreased by 59-91 % during transport from the Yellow Sea to the remote East China Sea and deposition to the sediment. This suggests that the source signal for POPs may be preserved under stable depositional environments, even though only a fraction of those pollutants are buried in open sea sediments.

Legacy and emerging organic contaminants in the polar regions.

The presence of numerous emerging organic contaminants (EOCs) and remobilization of legacy persistent organic pollutants (POPs) in polar regions have become significant concerns of the scientific communities, public groups and stakeholders. This work reviews the occurrences of EOCs and POPs and their long-range environmental transport (LRET) processes via atmosphere and ocean currents from continental sources to polar regions. Concentrations of classic POPs have been systematically monitored in air at several Arctic stations and showed seasonal variations and declining trends. These chemicals were also the major POPs reported in the Antarctica, while their concentrations were lower than those in the Arctic, illustrating the combination of remoteness and lack of potential local sources for the Antarctica. EOCs were investigated in air, water, snow, ice and organisms in the Arctic. Data in the Antarctica are rare. Reemission of legacy POPs and EOCs accumulated in glaciers, sea ice and snow may alter the concentrations and amplify their effects in polar regions. Thus, future research will need to understand the various biogeochemical and geophysical processes under climate change and anthropogenic pressures.

Polycyclic aromatic hydrocarbons in sediment-porewater system from the East China Sea: Occurrence, partitioning, and diffusion.

The distribution, partitioning behavior, and diffusion of polycyclic aromatic hydrocarbons (PAHs) within sediment-porewater system were determined in two cores obtained from the Min-Zhe coastal mud of the East China Sea (ECS). Depth profiles of apparently dissolved PAH levels exhibited greater variabilities, with their elevated levels at depth and a high abundance of two-to three-ring PAHs observed. These distribution and composition patterns were inconsistent with the corresponding sediment PAHs, indicating differences in controlling factors for PAHs present in the system. In addition to compound's hydrophobicity, low detection of heavier PAHs in porewater was possibly correlated with the sediment transport process, as indicated by a relatively high weathering ratio in southern Min-Zhe coastal mud. PAH sorption affinity to the collected core sediments exhibited a generally decreasing trend downcore, as expressed by sediment-porewater partition coefficients. This was consistent with the higher content of porewater PAHs in deep core sediment. The established sediment total organic carbon (TOC)-porewater partitioning profiles in cores were predicted with amorphous organic carbon (AOC)-, coal tar-, and TOC-based distribution models, suggesting a dominant nonlinear sorption of PAHs to AOC. Through activity determinations, PAH diffusion within porewater was elucidated, with significant upward and downward mass transfer for PAHs occurring in both cores. The upward diffusion in the core collected from northern Min-Zhe coastal mud was in significant association with sediment TOC. This suggests that sediment TOC (especially AOC)-desorption of lighter PAHs into porewater, and therefore the possibility of their participation in environmental cycling. Baseline toxicity potential and toxic unit calculations indicated a relatively low exposure risk for benthic organisms to porewater PAHs.

Distribution and gas-particle partitioning of polycyclic aromatic hydrocarbons over the East China Sea and Yellow Sea in spring: Role of atmospheric transport transition.

To elucidate the variations in the East Asian monsoon system during seasonal changes and their impacts on continental outflow of polycyclic aromatic hydrocarbons (PAHs), sixteen integrated air samples were collected during a research cruise covering the Yellow Sea (YS) and East China Sea (ECS) in mid-spring of 2017. The concentrations of total suspended particle (TSP), aerosol-phase PAH fractions, ratios of organic to elemental carbon (OC/EC) and gas-particle partitioning of atmospheric PAHs exhibited clear regional differences associated with variations in the monsoon regime. The total concentrations of 16 USEPA priority PAHs (Σ16PAHs) varied from 3.11 to 13.4 ng/m3 throughout the cruise, with medium-to-high molecular weight (MW) PAHs more enriched over the YS and north ECS than the south ECS. Together with the relatively low gaseous PAH fraction over the YS and north ECS (78 ± 4%) relative to the south ECS (95 ± 13%), this result indicates the pattern of regional atmospheric transport. The ratio of organic to elemental carbon varied significantly between the south ECS (lower than 4) and the YS and north ECS (greater than 4), indicating contributions from vehicle emissions and coal combustion or biomass burning, respectively, following different atmospheric input pathways of carbonaceous aerosols, as supported by backward trajectory analysis. Considering the gas-particle partitioning of PAHs, soot adsorption was the main partitioning mechanism in the study region; while high-MW PAHs in the YS and north ECS were influenced by both absorption and adsorption. The Koa absorption model provided better predictions for high-MW PAHs when continental air masses prevailed, despite underestimating the partition coefficients (kp) of low-MW PAHs. Meanwhile, predicted kp for medium MW PAHs was better estimated over the YS and ECS when Ksa was included.

Semi-centennial sediment records of HCHs and DDTs from the East China marginal seas: Role of lateral transport in catchment.

We reconstructed the history of the inputs of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) into the marine environment to reveal the time-dependent influence of sources and associated anthropogenic activities in China, based on 210Pb-dated cores from the East China marginal seas (ECMS). The temporal dynamics of pesticide contamination expresses as deposition fluxes, inventories, and half-life estimations varied among the cores, suggesting heterogeneity in transport pathways of pollutants. The depth profiles of pesticide inputs closely followed their historical production and application timelines in China, and were also affected by human activities in catchments, with general declines in HCH and DDT inputs to the coring sites after their peak deposition. Despite the prevalence of occurrence of weathered HCH/DDT in the cores, there were clear source-dependent differences in isomeric composition and accumulation between before and after these pesticides were banned. α-HCH and p,p'-DDT were relatively more enriched in sediments from the pre-ban period when heavy technical HCHs and DDTs use occurred, as indicated by the higher α-/ß-HCH and lower (DDE + DDD)/DDTs ratios, and the larger fractions of α-HCH and p,p'-DDT influxes to the coring sites in the ΣHCH and ΣDDT fluxes, respectively, while this pattern shifted to be historical residue-based in the post-ban period. The difference in the recent influxes of pesticides to core sediments and their higher post-ban inventories highlight the increasing importance of historical sources over time and continuous input of weathered residues into marine environment via lateral transport.

Atmospheric legacy organochlorine pesticides and their recent exchange dynamics in the Northwest Pacific Ocean.

The occurrence and air-sea gas exchange of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and chlordanes were determined in the Northwest Pacific Ocean (NWP) in spring to elucidate their current pollution status and fate. ΣHCHs, ΣDDTs, and Σchlordanes in air (sum of gaseous and aerosol phase) ranged from 9.37 to 102, from 1.73 to 12.8, and from 0.24 to 14.9 pg/m3, respectively, with their dissolved levels being 30.7-518, 7.10-80.5, and 0.25-7.10 pg/L, respectively. HCHs, DDTs, and chlordanes cause substantial contamination of the air and seawater of the East China Sea (ECS), indicating significant OCP inputs from China. Isomer ratios of HCHs and DDTs provided a fingerprint of East Asian emissions of legacy OCPs, with the pollution profiles of HCHs and DDTs dominated by lindane and combined dicofol-type and weathered technical DDTs, respectively. The former result is consistent with the apparent decline in air α-HCH levels over the ECS. Different from still net deposition of gaseous α- and γ-HCH in the NWP, outgassing of trans-chlordane, cis-chlordane, and DDTs other than dicofol-sourced o,p'-DDT was indicated. This observation attributes to intensive historical usage of technical HCHs and the prevalence of lindane pollution in East Asia, and demonstrates the transitioning role of seawater as a source for residual OCPs in the East Asia-NWP region. Significant subcooled liquid vapor pressure-based relationships for legacy OCPs were identified mainly in marine air masses; these were different from land-sourced polybrominated diphenyl ethers, and suggested a heterogeneous role of ocean- and land-based sources in atmospheric partitioning of these pollutants.

Occurrence, air-sea exchange, and gas-particle partitioning of atmospheric polybrominated diphenyl ethers from East Asia to the Northwest Pacific Ocean.

The occurrence, air-sea exchange, and gas-particle partitioning of polybrominated diphenyl ethers (PBDEs) were analyzed during a 2015 research expedition from the East China Sea (ECS) to the open Northwest Pacific Ocean (NWP). The sum of 13 PBDEs (Σ13PBDEs) in air and surface seawater varied in the range of 0.54-14.5. pg m-3 and 0.60-13.5 pg L-1, respectively, with the highest concentrations observed in the ECS. The Clausius-Clapeyron approach and air mass origin analysis indicated that continued primary emissions of PBDEs, particularly BDE-209, from East Asian sources governed the spatial variability of air PBDEs over the NWP through long-range atmospheric transport (LRAT). Net air-to-seawater gas deposition of PBDEs was evidenced based on the fugacity calculation with sum fluxes of seven selected PBDEs ranging from -45 to -582 pg m-2 d-1. Following the substantial advection of aerosol phase BDE-209 over the ECS, dry particle deposition dominated the input pathway of PBDEs into the ECS, whereas in the open NWP, relatively free from the influence of the land emissions, fluxes in PBDE absorption and in dry particle deposition were comparable. This suggests an impact of continental outflow on the fate of atmospheric PBDEs over the NWP. Regarding gas-particle partitioning, PBDEs over the NWP were obviously absorbed into continental organic aerosols during atmospheric transport, except for BDE-209, which tended to remain within the steady state.

Sedimentary records of polychlorinated biphenyls in the East China Marginal Seas and Great Lakes: Significance of recent rise of emissions in China and environmental implications.

Polychlorinated biphenyls (PCBs) in dated sediment cores from the East China Marginal Seas (ECMSs) and the chronology of the net fluxes to sediments were analyzed. The accumulation of 27 PCBs (ΣPCBs) in the ECMS sediments is about 5-26 ng cm-2, with the net depositional fluxes of ΣPCBs 10 times lower than those observed in the Great Lakes during the 1960s-1970s. Exponential increases in PCB deposition to the ECMS sediments since the 1990s were observed, which closely follows the fast growth of PCB emissions from industrial thermal processes and e-waste related sources in China. Recent PCB fluxes to the study sites in the ECMSs and the Great Lakes are comparable; the former surged forward with a rising tendency, while the latter showed continued decline after the late 1970s. Due to the different PCB application histories and sources between the two regions, the ECMS sediments may remain as a net sink for land-derived PCBs, while sediments in the Great Lake may have been acting as a secondary source releasing PCBs to water. A higher proportion of trichlorobiphenyls in the ECMS sediments than the Great Lakes was indicated, which may imply the net transport of atmospheric PCBs from China.

Occurrence, gas-particle partitioning, and sources of polybrominated diphenyl ethers in the atmosphere over the Yangtze River Estuary, East China Sea.

To investigate the occurrence, gas-particle partitioning, and potential sources of polybrominated diphenyl ethers (PBDEs) in the atmosphere over the Yangtze River Estuary, gas and particle samples were collected at the remote Huaniao Island, East China Sea, during a whole year from 2013 to 2014. Nine PBDEs, with total atmospheric concentration of Σ9BDEs of 20.3 ±â€¯26.5 pg/m3, were found in both the gas and particle phases in most samples. BDE-209 dominated both the gas and particle phases, which is consistent with the PBDE usage record in China. Seasonal variation of particle-phase Σ9BDEs was observed, with the highest concentration in winter and the lowest in summer; however, a reversed seasonal trend was observed in the gas phase. Correlation analysis between log Kp and log KOA suggested that the gas-particle (G/P) partitioning was in a non-equilibrium state, particularly for BDE-209 throughout the year. The KOA-based adsorption model prediction performed relatively well for the particle-phase fraction of Br<10-BDEs, but largely overestimated BDE-209. A steady-state model could be superior to predict G/P partitioning of BDE-209 based on annual values, though with the exception of summer samples. A relatively higher gas-phase distribution for BDE-209 than high-brominated BDEs was observed, especially in summer, when it reached 73%, implying a sustained input of gas-phase BDE-209. The potential source contribution function showed that the possible source regions for BDE-209 included Shandong and Jiangsu Provinces (the main BDE-209 production regions in China), the Yangtze River Delta region, and the southeastern coastal areas (which hosts intensive electronic waste recycling activities).

Deposition flux and mass inventory of polychlorinated biphenyls in sediments of the Yangtze River Estuary and inner shelf, East China Sea: Implications for contributions of large-river input and e-waste dismantling.

Surface sediment samples were collected from the Yangtze River Estuary (YRE) to the inner-shelf mud area of the East China Sea (ECS) for a comprehensive study of the sources and fates of polychlorinated biphenyls (PCBs) based on their spatial distribution, deposition flux, and mass inventory. The total concentrations of 32 PCBs (Σ32PCBs) varied from 0.3 to 11.9 ng/g dry weight. Under strong hydrodynamic conditions, the weak correlations between TOC or MD and Σ32PCB concentrations were observed in the YRE. In contrast, there were relatively well relationships of PCBs with TOC content and sediment grain size in the inner shelf of the ECS due to the influence of hydrological sorting from the YRE to the inner shelf of the ECS. This suggests that the Yangtze River input plays a considerable role in controlling the distribution of PCBs in the coastal ECS. Compared with the annual discharge of Σ32PCBs from the Yangtze River to the sea (3.21 t/yr), the deposition flux was estimated to be ~2.63 t/yr. Furthermore, a total mass inventory of 50 tons in the sediments suggests that the YRE and inner shelf mud of the ECS represents an important global sink of PCBs. Estimated 21-39% of sedimentary PCBs were derived from local emissions (mainly dismantling of electronic waste) aside from Yangtze River input. Higher proportions of penta-CBs were also observed near the central Zhejiang Coast, providing further evidence that the local emission from e-waste dismantling near the coast is a significant contributor to sedimentary PCBs in the coastal ECS.

Air-sea exchange and gas-particle partitioning of polycyclic aromatic hydrocarbons over the northwestern Pacific Ocean: Role of East Asian continental outflow.

We measured 15 parent polycyclic aromatic hydrocarbons (PAHs) in atmosphere and water during a research cruise from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) in the spring of 2015 to investigate the occurrence, air-sea gas exchange, and gas-particle partitioning of PAHs with a particular focus on the influence of East Asian continental outflow. The gaseous PAH composition and identification of sources were consistent with PAHs from the upwind area, indicating that the gaseous PAHs (three-to five-ring PAHs) were influenced by upwind land pollution. In addition, air-sea exchange fluxes of gaseous PAHs were estimated to be -54.2-107.4 ng m-2 d-1, and was indicative of variations of land-based PAH inputs. The logarithmic gas-particle partition coefficient (logKp) of PAHs regressed linearly against the logarithmic subcooled liquid vapor pressure (logPL0), with a slope of -0.25. This was significantly larger than the theoretical value (-1), implying disequilibrium between the gaseous and particulate PAHs over the NWP. The non-equilibrium of PAH gas-particle partitioning was shielded from the volatilization of three-ring gaseous PAHs from seawater and lower soot concentrations in particular when the oceanic air masses prevailed. Modeling PAH absorption into organic matter and adsorption onto soot carbon revealed that the status of PAH gas-particle partitioning deviated more from the modeling Kp for oceanic air masses than those for continental air masses, which coincided with higher volatilization of three-ring PAHs and confirmed the influence of air-sea exchange. Meanwhile, significant linear regressions between logKp and logKoa (logKsa) for PAHs were observed for continental air masses, suggesting the dominant effect of East Asian continental outflow on atmospheric PAHs over the NWP during the sampling campaign.

[Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in urban rainfall runoff].

Runoff samples were collected from traffic roads, campus, residential road and roof in a typical rain event. Polycyclic aromatic hydrocarbons (PAHs) in both dissolved and particle phases were investigated at impervious surfaces. The PAHs wash-off process at different monitoring sites was analyzed. The scatters of first flush were conducted in a method of fitting power function to quantitatively assess the magnitude of first flush effect (FFE). The sources of PAHs were identified using factor analysis. The results showed that PAHs concentrations in runoff samples varied from 317.21 ng x L(-1) to 10364.3 ng x L(-1) with the maximal and minimal contents of PAHs found on Longwu Road and campus, respectively. The values of event mean concentration ( EMC) varied considerably at different sampling sites. The concentration of washed-off pollutant generally decreased with runoff duration, which showed an obvious attenuation trend. The runoff process indicated the occurrence of FFE at different levels. PAHs mainly came from the incomplete combustion of fossil fuels, oil leakage and coking, and the contribution of each source was different in accordance with various surfaces.