Publications by authors named "Zhipeng Bai"

71 Publications

Positive associations of serum perfluoroalkyl substances with uric acid and hyperuricemia in children from Taiwan.

Environ Pollut 2016 May 10;212:519-524. Epub 2016 Mar 10.

Department of Environmental and Occupational Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, ROC; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei 100, Taiwan, ROC. Electronic address:

To investigate the risk of hyperuricemia in relation to Perfluoroalkyl substances (PFASs) in children from Taiwan, 225 Taiwanese children aged 12-15 years were recruited from 2009 to 2010. Linear and logistic regression models were employed to examine the influence of PFASs on serum uric acid levels. Findings revealed that eight of ten PFASs analyses were detected in >94% of the participants' serum samples. Multivariate linear regression models revealed that perfluorooctanic acid (PFOA) was positively associated with serum uric acid levels (β = 0.1463, p < 0.05). Of all the PFASs analyses, only PFOA showed a significant effect on elevated levels of hyperuricemia (aOR = 2.16, 95%CI: 1.29-3.61). When stratified by gender, the association between serum PFOA and uric acid levels was only evident among boys (aOR = 2.76, 95%CI: 1.37-5.56). In conclusion, PFOA was found to be associated with elevated serum levels of uric acid in Taiwanese children, especially boys. Further research is needed to elucidate these links.
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http://dx.doi.org/10.1016/j.envpol.2016.02.050DOI Listing
May 2016

Gravimetric analysis for PM2.5 mass concentration based on year-round monitoring at an urban site in Beijing.

J Environ Sci (China) 2016 Feb 11;40:154-60. Epub 2016 Jan 11.

State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address:

Daily PM2.5 (particulate matter with an aerodynamic diameter of below 2.5 μm) mass concentrations were measured by gravimetric analysis in Chinese Research Academy of Environmental Sciences (CRAES), in the northern part of the Beijing urban area, from December 2013 to April 2015. Two pairs of Teflon (T1/T2) and Quartz (Q1/Q2) samples were obtained, for a total number of 1352 valid filters. Results showed elevated pollution in Beijing, with an annual mean PM2.5 mass concentration of 102 μg/m(3). According to the calculated PM2.5 mass concentration, 50% of our sampling days were acceptable (PM2.5<75 μg/m(3)), 30% had slight/medium pollution (75-150 μg/m(3)), and 7% had severe pollution (> 250 μg/m(3)). Sampling interruption occurred frequently for the Teflon filter group (75%) in severe pollution periods, resulting in important data being missing. Further analysis showed that high PM2.5 combined with high relative humidity (RH) gave rise to the interruptions. The seasonal variation of PM2.5 was presented, with higher monthly average mass concentrations in winter (peak value in February, 422 μg/m(3)), and lower in summer (7 μg/m(3) in June). From May to August, the typical summer period, least severe pollution events were observed, with high precipitation levels accelerating the process of wet deposition to remove PM2.5. The case of February presented the most serious pollution, with monthly averaged PM2.5 of 181 μg/m(3) and 32% of days with severe pollution. The abundance of PM2.5 in winter could be related to increased coal consumption for heating needs.
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http://dx.doi.org/10.1016/j.jes.2015.09.015DOI Listing
February 2016

Characteristics of atmospheric single particles during haze periods in a typical urban area of Beijing: A case study in October, 2014.

J Environ Sci (China) 2016 Feb 11;40:145-53. Epub 2016 Jan 11.

State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. E-mail: Electronic address:

To investigate the composition and possible sources of particles, especially during heavy haze pollution, a single particle aerosol mass spectrometer (SPAMS) was deployed to measure the changes of single particle species and sizes during October of 2014, in Beijing. A total of 2,871,431 particles with both positive and negative spectra were collected and characterized in combination with the adaptive resonance theory neural network algorithm (ART-2a). Eight types of particles were classified: dust particles (dust, 8.1%), elemental carbon (EC, 29.0%), organic carbon (OC, 18.0%), EC and OC combined particles (ECOC, 9.5%), Na-K containing particles (NaK, 7.9%), K-containing particles (K, 21.8%), organic nitrogen and potassium containing particles (KCN, 2.3%), and metal-containing particles (metal, 3.6%). Three haze pollution events (P1, P2, P3) and one clean period (clean) were analyzed, based on the mass and number concentration of PM2.5 and the back trajectory results from the hybrid single particle Lagrangian integrated trajectory model (Hysplit-4 model). Results showed that EC, OC and K were the major components of single particles during the three haze pollution periods, which showed clearly increased ratios compared with those in the clean period. Results from the mixing state of secondary species of different types of particles showed that sulfate and nitrate were more readily mixed with carbon-containing particles during haze pollution episodes than in clean periods.
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http://dx.doi.org/10.1016/j.jes.2015.10.027DOI Listing
February 2016

Heavy haze episodes in Beijing during January 2013: Inorganic ion chemistry and source analysis using highly time-resolved measurements from an urban site.

Sci Total Environ 2016 Feb 3;544:319-29. Epub 2015 Dec 3.

State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.

The heavy air pollution that occurred in Beijing in January of 2013 attracted intense attention around the world. During this period, we conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site of Beijing, and investigated ion chemistry and potential sources. Hourly concentrations of Cl(-), NO3(-), SO4(2-), Na(+), NH4(+), K(+), Mg(2+), and Ca(2+) were measured. Peak concentrations of SO4(2-) and NO3(-) were observed on the 10th-15th, 21st-24th, and the 26th-30th during this monitoring campaign. The percentages of SO4(2-) and NH4(+) in total ion concentration increased with the enhancement of PM2.5 concentrations, indicating that high concentrations of SO4(2-) and NH4(+) may play important roles in the formation of haze episodes. The ratio of [NO3(-)]/[SO4(2-)] was calculated, revealing that the sources of SO4(2-) would contribute more to the formation of PM2.5 than mobile sources. Diurnal variations of SO4(2-), NO3(-), NH4(+) (SNA) exhibited a similar pattern, with high concentrations at night and low levels during the day, revealing that meteorological conditions, such as mixing layer height, relative humidity, were likely to be responsible for high levels of SNA at night. The roles of meteorological conditions were further discussed in the formation of secondary inorganic ions. Relative humidity and temperature played key roles and exhibited positive correlations with secondary inorganic ions. An aerosol inorganics simulation model showed that SNA existed mainly in the aqueous phase during the sampling period. Furthermore, potential sources were identified by applying positive matrix factorization model. Secondary nitrate, secondary sulfate, coal combustion and biomass burning, as well as fugitive dust, were considered to be major contributors to total ions.
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http://dx.doi.org/10.1016/j.scitotenv.2015.10.053DOI Listing
February 2016

Individual and population intake fractions of diesel particulate matter (DPM) in bus stop microenvironments.

Environ Pollut 2015 Dec 14;207:161-7. Epub 2015 Sep 14.

Department of Civil and Environmental Engineering, University of Windsor, Windsor, Ontario N9B 3P4, Canada.

Diesel particulate matter (DPM) is associated with adverse human health effects. This study aims to investigate the relationship between DPM exposure and emissions by estimating the individual intake fraction (iFi) and population intake fraction (iFp) of DPM. Daily average concentrations of particulate matter at two bus stops during rush hours were measured, and then they were apportioned to DPM due to heavy-duty diesel bus emissions using Chemical Mass Balance Model. The DPM emissions of diesel buses for different driving conditions (idling, creeping and traveling) were estimated on the basis of field observations and published emission factors. The median iFi of DPM was 0.67 and 1.39 per million for commuters standing at the bus stop and pedestrians/cyclists passing through the bus stop during rush hours, respectively. The median iFp of DPM was 94 per million. Estimations of iFi and iFp of DPM are potentially significant for exposure assessment and risk management.
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http://dx.doi.org/10.1016/j.envpol.2015.09.005DOI Listing
December 2015

Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

Sci Total Environ 2015 May 19;515-516:101-8. Epub 2015 Feb 19.

Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.

107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on location and sampling method.
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http://dx.doi.org/10.1016/j.scitotenv.2015.02.034DOI Listing
May 2015

Exposure measurement, risk assessment and source identification for exposure of traffic assistants to particle-bound PAHs in Tianjin, China.

J Environ Sci (China) 2014 Feb;26(2):448-57

To investigate the levels of exposure to particulate-bound polycyclic aromatic hydrocarbon (PAH) and to estimate the risk these levels pose to traffic assistants (TAs) in Tianjin (a megacity in North China), a measurement campaign (33 all-day exposure samples, 25 occupational-exposure samples and 10 indoor samples) was conducted to characterize the TAs' exposure to PAHs, assess the cancer risk and identify the potential sources of exposure. The average total exposure concentration of 14 PAHs was approximately 2871 +/- 928 ng/m3 (on-duty), and 1622 +/- 457 ng/m3 (all-day). The indoor PAHs level was 1257 +/- 107 ng/m3. After 8000 Monte Carlo simulations, the cancer risk resulting from exposure to PAHs was found to be approximately 1.05 x 10(-4). A multivariate analysis was applied to identify the potential sources, and the results showed that, in addition to vehicle exhaust, coal combustion and cooking fumes were also another two important contributors to personal PAH exposure. The diagnostic ratios of PAH compounds agree with the source apportionment results derived from principal component analysis.
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http://dx.doi.org/10.1016/s1001-0742(13)60427-1DOI Listing
February 2014

A comprehensive assessment of human exposure to phthalates from environmental media and food in Tianjin, China.

J Hazard Mater 2014 Aug 2;279:133-40. Epub 2014 Jul 2.

College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin 300071, China.

A total of 448 samples including foodstuffs (rice, steamed bun, vegetables, meat, poultry, fish, milk and fruits), ambient PM10, drinking water, soil, indoor PM10 and indoor dust samples from Tianjin were obtained to determine the distribution of six priority phthalates (PAEs) and assess the human exposure to them. The results indicated that DBP and DEHP were the most frequently detected PAEs in these samples. The concentrations of PAEs in environmental media were higher than those in food. We estimated the daily intake (DI) of PAEs via ingestion, inhalation and dermal absorption from five sources (food, water, air, dust and soil). Dietary intake was the main exposure source to DEP, BBP, DEHP and DOP, whereas water ingestion/absorption was the major source of exposure to DBP, DEHP and DOP. Although food and water were the overwhelmingly predominant sources of PAEs intake by Tianjin population, contaminated air was another important source of DMP, DEP and DBP contributing to up to 45% of the exposure. The results of this study will help in understanding the major pathways of human exposure to PAEs. These findings also suggest that human exposure to phthalate esters via the environment should not be overlooked.
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http://dx.doi.org/10.1016/j.jhazmat.2014.06.055DOI Listing
August 2014

Residential indoor and personal PM10 exposures of ambient origin based on chemical components.

J Expo Sci Environ Epidemiol 2014 Jul 7;24(4):428-36. Epub 2014 May 7.

College of Environmental Science and Engineering, Nankai University, Tianjin, China.

Many studies have focused on the relationships of particulate matter between indoor, outdoor and personal exposure; however, considerable uncertainties remain regarding the portion of indoor particles and personal exposure of ambient origin. As part of the Particle Exposure Assessment for Community Elderly (PEACE) study in Tianjin, China, we have further interpreted the relationships between personal, residential indoor, outdoor and community PM10 (particulate matter with aerodynamic diameters of less than 10 μm). Comparisons of the chemical compositions of PM10 samples were performed using the coefficient of divergence (COD). A robust regression method, least-trimmed squared (LTS) regression, was used to estimate the infiltration factors of PM10 from residential outdoor to indoor environments based on the particulate component concentrations. Personal exposures of ambient origin were also estimated. A relatively good correlation was found between the personal and indoor PM10 samples with respect to chemical composition. The infiltration factors (Finf) of the residential indoor-outdoor PM10 were 0.74±0.31 (mean±SD) in summer and 0.44±0.22 in winter, with medians of 0.98 and 0.48, respectively. The residential outdoor contributions to the indoor environments were 87±55 μg/m(3) in summer and 80±54 μg/m(3) in winter, with medians of 75 μg/m(3) and 61 μg/m(3), respectively. The personal exposures of ambient origin were 92±44 μg/m(3) in summer and 89±47 μg/m(3) in winter, with medians of 81 μg/m(3) and 80 μg/m(3), respectively. This study indicated that the infiltrations in an urbanized area in North China exhibited a seasonal difference: the residential outdoor contributions to residential indoor environments were larger in summer due to the higher use of natural ventilation. The personal exposures of ambient origin were comparable during the different seasons, whereas those of non-ambient origin were higher in summer than in winter.
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http://dx.doi.org/10.1038/jes.2014.28DOI Listing
July 2014

Global gene expression profiling of human bronchial epithelial cells exposed to airborne fine particulate matter collected from Wuhan, China.

Toxicol Lett 2014 Jul 21;228(1):25-33. Epub 2014 Apr 21.

Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China. Electronic address:

Background: Many studies have linked ambient fine particulate matter (PM2.5) air pollution to different cardiopulmonary diseases in the general population. However the complex mechanisms underlying PM2.5-induced adverse health effects are not yet to be fully elucidated.

Method: In this study, we aimed to identify genes and pathways that may contribute to PM2.5-induced lung toxicity in humans through genome-wide approaches. Human bronchial epithelial (HBE) cells, exposed to various concentrations of PM2.5 collected from Wuhan, China, showed decreased cell viability in a dose-dependent manner. HBE cells were exposed to 200 μg/ml and 500 μg/ml PM2.5 and microarrays were used to obtain a global view of the transcriptomic responses.

Results: A total of 970 and 492 genes were identified that significantly changed after 200 μg/ml and 500 μg/ml PM2.5 exposures, respectively. PM2.5 induced a large number of genes involved in inflammatory and immune response, response to oxidative stress, and response to DNA damage stimulus, which might contribute to PM2.5 related cardiopulmonary diseases. Pathway analysis revealed that different dose of PM2.5 triggered partially common disturbed pathways. Flow cytometry assay evidenced that there were statistically significant differences in the G1 phase of cell cycle after low or high-dose PM2.5 exposure when compared to the unexposed controls. Only high-dose PM2.5 significantly increased the proportion of cells in the S phase of cell cycle.

Conclusion: We identified many genes and pathways that altered significantly in HBE cells after PM2.5 exposures. These findings are important in providing further understanding of the mechanisms underlying PM2.5-induced adverse health effects.
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http://dx.doi.org/10.1016/j.toxlet.2014.04.010DOI Listing
July 2014

[Effects of carbon components of fine particulate matter (PM2.5) on atherogenic index of plasma].

Zhonghua Yu Fang Yi Xue Za Zhi 2014 Jan;48(1):33-7

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Objective: To evaluate associations between carbon constituents of fine particulate matter (PM2.5) and atherogenic index of plasma (AIP).

Methods: We collected subjects from two communities by a system sampling, and 112 people aged over 60 years old without cardiovascular disease were recruited. The levels of cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) of objects, and personal exposure to PM2.5 were measured on December, 2011. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) of PM2.5 were detected and AIP was calculated according to its definition.

Results: The value of AIP among the 112 subjects was 0.05 ± 0.26. Personal exposure concentration of PM2.5 and its carbon components (TC,OC and EC) were (164.75 ± 110.67), (53.86 ± 29.65), (44.93 ± 26.37) and (9.49 ± 5.75) µg/m(3), respectively. The Pearson analysis showed the linear relationship between TC,OC,EC and AIP, all significant positive correlations. The correlation coefficients were TC (r = 0.307, P < 0.05),OC (r = 0.287, P < 0.05) and EC (r = 0.252, P < 0.05), respectively. The multiple logistic regression analysis showed that when the AIP risk categories were selected as dependent variable and low risk group as reference group, the regression coefficient of TC,OC and EC was separately 1.03 (95%CI:1.01-1.05), 1.03 (95%CI:1.01-1.05), 1.12 (95%CI:1.02-1.22) in the high risk group; while there was no statistical significance of the regression coefficient and OR in the middle risk group.

Conclusion: There was stable associations between the carbon constituents (TC,OC and EC) of fine Particulate Matter (PM2.5) and AIP. The findings suggested that carbon components of PM2.5 should be considered as risk factors of atherogenic.
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January 2014

Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China.

J Environ Sci (China) 2014 Jan;26(1):160-6

Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons (PAHs) are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4-ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efficient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.
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http://dx.doi.org/10.1016/s1001-0742(13)60393-9DOI Listing
January 2014

Chemical composition, mass closure and sources of atmospheric PM10 from industrial sites in Shenzhen, China.

J Environ Sci (China) 2013 Aug;25(8):1626-35

Chinese Research Academy of Environmental Sciences, Beijing 100012, China.

Concentrations of atmospheric PM10 and chemical components (including twenty-one elements, nine ions, organic carbon (OC) and elemental carbon (EC)) were measured at five sites in a heavily industrial region of Shenzhen, China in 2005. Results showed that PM10 concentrations exhibited the highest values at 264 microg/m3 at the site near a harbor with the influence of harbor activities. Sulfur exhibited the highest concentrations (from 2419 to 3995 ng/m3) of all the studied elements, which may be related to the influence of coal used as fuel in this area for industrial plants. This was verified by the high mass percentages of SO4(2-), which accounted for 34.3%-39.7% of the total ions. NO3-/SO4(2-) ratios varied from 0.64-0.71, which implies coal combustion was predominant compared with vehicle emission. The anion/cation ratios range was close to 0.95, indicating anion deficiency in this region. The harbor site showed the highest OC and EC concentrations, with the influence of emission from vessels. Secondary organic carbon accounted for about 22.6%-38.7% of OC, with the highest percentage occurring at the site adjacent to a coal-fired power plant and wood plant. The mass closure model performed well in this heavily industrial region, with significant correlation obtained between chemically determined and gravimetrically measured PM10 mass. The main constituents of PM10 were found to be organic materials (30.9%-69.5%), followed by secondary inorganic aerosol (7.9%-25.0%), crustal materials (6.7%-13.8%), elemental carbon (3.5%-10.8%), sea salt (2.4%-6.2%) and trace elements (2.0%-4.9%) in this heavily industrialized region. Principal component analysis indicated that the main sources for particulate matter in this industrial region were crustal materials and coal/wood combustion, oil combustion, secondary aerosols, industrial processes and vehicle emission.
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http://dx.doi.org/10.1016/s1001-0742(12)60238-1DOI Listing
August 2013

Combined use of WEPS and Models-3/CMAQ for simulating wind erosion source emission and its environmental impact.

Sci Total Environ 2014 Jan 25;466-467:762-9. Epub 2013 Aug 25.

Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Urban and Environmental Science, Tianjin Normal University, Tianjin 300387, China.

The wind erosion source is the greatest contributor of PM₁₀ in Tianjin, China. It is difficult to establish a PM₁₀ emission inventory for the wind erosion source because of the complicated conditions affecting PM₁₀ emissions from wind erosion. In this study, a novel method is developed to establish a PM₁₀ emission inventory for the wind erosion source by using the Wind Erosion Prediction System (WEPS) model with 1 × 1 km spatial resolution. In 2011, the average annual emission of PM₁₀ in Tianjin was 0.373 tons km(-2) (1.113 tons km(-2) in the heating period, 0.237 tons km(-2) in the sand period, and 0.013 tons km(-2) in the non-heating period), and the total PM₁₀ emission was 904,871.6 tons (221,080.7 tons in the heating period, 52,977.8 tons in the sand period, and 1953.2 tons in the non-heating period). After establishing the PM₁₀ emission inventory for the wind erosion source in this manner, the data were input into Model-3/SMOKE. The contribution of the PM₁₀ concentration from the wind erosion source was estimated using the Community Multi-scale Air Quality (Model-3/CMAQ) model and was compared with the monitoring value and the source apportionment results using the chemical mass balance (CMB) method. For this comparison, over the entire year, the R(2) was 0.711. More specifically, R(2) was 0.664, 0.733, and 0.679 in the heating, non-heating, and sand periods, respectively. Thus, we have obtained a reliable method for estimating the source of PM₁₀ from wind erosion.
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http://dx.doi.org/10.1016/j.scitotenv.2013.07.090DOI Listing
January 2014

Investigation of speciated VOC in gasoline vehicular exhaust under ECE and EUDC test cycles.

Sci Total Environ 2013 Feb 12;445-446:110-6. Epub 2013 Jan 12.

The College of Environmental Science and Engineering, State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Nankai University, Tianjin 300071, PR China.

The emission factors and compositions of volatile organic compounds (VOC) in exhaust gas from in-use gasoline passenger cars were characterized using a chassis dynamometer. Three passenger cars were tested at the ECE and the EUDC drive cycles to represent both urban and suburban driving scenarios. Exhaust gas was collected in Summa canisters and analyzed by gas chromatography-mass spectrometry (GC-MS). Common gaseous emissions (CH(4), NOx, CO, and CO(2)) were measured by an on-board monitoring system. The VOC emission factors of different cars ranged from 0.10 to 0.25 g km(-1) at the ECE cycle, and 0.01-0.02 g km(-1) at the EUDC cycle. A total of 57 individual VOC were detected in the exhaust gas, and the weight percentages were very consistent among the three cars. Ethylene (11.80 wt.%), toluene (11.27 wt.%), and benzene (8.83 wt.%) were the most abundant VOC in exhaust gas. Aromatics (38.32%) dominated the low speed conditions (ECE), while alkanes (37.34%) were the major compounds at the high speed condition (EUDC). The total amount of alkenes did not change much between those two cycles, while ethylene is abundant in the ECE and EUDC cycles. Ozone formation potential (OFP) was calculated to estimate the ozone yield from VOC emissions by gasoline cars and the results showed that OFP of VOC emission at the ECE cycle was about ten times higher than that at the EUDC cycle.
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http://dx.doi.org/10.1016/j.scitotenv.2012.12.044DOI Listing
February 2013

Measurement of air exchange rates in different indoor environments using continuous CO2 sensors.

J Environ Sci (China) 2012 ;24(4):657-64

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Sciences and Engineering, Nankai University, Tianjin 300071, China.

A new air exchange rate (AER) monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs (0.1-10.0 hr(-1)). AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers. Indoor temperature, relative humidity (RH), and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved: duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr(-1) in dormitories, air-conditioned classrooms, classrooms with an air circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr(-1) in fall, and 0.12 to 1.39 hr(-1) in winter with a median AER of 1.15.
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http://dx.doi.org/10.1016/s1001-0742(11)60812-7DOI Listing
September 2012

Diversities of phthalate esters in suburban agricultural soils and wasteland soil appeared with urbanization in China.

Environ Pollut 2012 Nov 20;170:161-8. Epub 2012 Jul 20.

College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.

The distribution of six priority phthalic acid esters (PAEs) in suburban farmland, vegetable, orchard and wasteland soils of Tianjin were obtained with gas chromatography-mass spectrometer analysis in 2009. Results showed that total PAEs varied from 0.05 to 10.4 μg g(-1), with the median value as 0.32 μg g(-1). Di-(2-ethylhexyl) phthalate and di-n-butyl phthalate are most abundant species. PAEs concentrations for the four types of soils exhibited decreasing order as vegetable soil > wasteland soil > farmland soil > orchard soil. PAEs exhibited elevated levels in more developed regions when compared with other studies. The agricultural plastic film could elevate the PAEs contents in soils. Principal component analysis indicated the emission from cosmetics and personal care products and plasticizers were important sources for PAEs in suburban soils in Tianjin. The higher PAEs contents in wasteland soils from suburban area should be paid more attention owing to large amounts of solid wastes appeared with the ongoing urbanization.
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http://dx.doi.org/10.1016/j.envpol.2012.06.017DOI Listing
November 2012

Theoretical study on the reaction mechanism of ozone addition to the double bonds of keto-limonene.

J Environ Sci (China) 2012 ;24(1):147-51

College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.

The reaction mechanism of ozone (O3) addition to the double bonds of gas phase keto-limonene was investigated using ab initio methods. Two different possibilities for O3 addition to the double bond were considered and two corresponding van der Waals complexes (Complex 1 and Complex 2) were found for 1-endo and 2-endo. The rate constants were calculated using the transition state theory at the CCSD(T)/6-31G(d) + CF//B3LYP/6-31G(d,p) level. The high-pressure limit of the total rate constant at 298 K was 3.51 x 10(-16) cm3/(molecule x sec), which was in a good agreement with the experimental data.
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http://dx.doi.org/10.1016/s1001-0742(11)60738-9DOI Listing
August 2012

Association of particulate air pollution with daily mortality: the China Air Pollution and Health Effects Study.

Am J Epidemiol 2012 Jun 17;175(11):1173-81. Epub 2012 Apr 17.

School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China.

China is one of the few countries with some of the highest particulate matter levels in the world. However, only a small number of particulate matter health studies have been conducted in China. The study objective was to examine the association of particulate matter with an aerodynamic diameter of less than 10 μm (PM(10)) with daily mortality in 16 Chinese cities between 1996 and 2008. Two-stage Bayesian hierarchical models were applied to obtain city-specific and national average estimates. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The averaged daily concentrations of PM(10) in the 16 Chinese cities ranged from 52 μg/m(3) to 156 μg/m(3). The 16-city combined analysis showed significant associations of PM(10) with mortality: A 10-μg/m(3) increase in 2-day moving-average PM(10) was associated with a 0.35% (95% posterior interval (PI): 0.18, 0.52) increase of total mortality, 0.44% (95% PI: 0.23, 0.64) increase of cardiovascular mortality, and 0.56% (95% PI: 0.31, 0.81) increase of respiratory mortality. Females, older people, and residents with low educational attainment appeared to be more vulnerable to PM(10) exposure. Conclusively, this largest epidemiologic study of particulate air pollution in China suggests that short-term exposure to PM(10) is associated with increased mortality risk.
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http://dx.doi.org/10.1093/aje/kwr425DOI Listing
June 2012

Chemical compositions and sources of atmospheric PM10 in heating, non-heating and sand periods at a coal-based city in northeastern China.

J Environ Monit 2012 Mar 17;14(3):852-65. Epub 2012 Jan 17.

College of Environmental Science and Engineering, Nankai University, 94 Weijin Road, Tianjin, 300071, China.

Mass concentrations and chemical components (18 elements, 9 ions, organic carbon [OC] and elemental carbon [EC]) in atmospheric PM(10) were measured at five sites in Fushun during heating, non-heating and sand periods in 2006-2007. PM(10) mass concentrations varied from 62.0 to 226.3 μg m(-3), with 21% of the total samples' mass concentrations exceeding the Chinese national secondary standard value of 150 μg m(-3), mainly concentrated in heating and sand periods. Crustal elements, trace elements, water-soluble ions, OC and EC represented 20-47%, 2-9%, 13-34%, 15-34% and 13-25% of the particulate matter mass concentrations, respectively. OC and crustal elements exhibited the highest mass percentages, at 27-34% and 30-47% during heating and sand period. Local agricultural residuals burning may contribute to EC and ion concentrations, as shown by ion temporal variation and OC and EC correlation analysis. Heavy metals (Cr, Ni, Zn, Cu and Mn) from coal combustion and industrial processes should be paid attention to in heating and sand periods. The anion/cation ratios exhibited their highest values for the background site with the influence of stationary sources on its upper wind direction during the sand period. Secondary organic carbon were 1.6-21.7, 1.5-23.0, 0.4-17.0, 0.2-33.0 and 0.2-21.1 μg m(-3), accounting for 20-77%, 44-88%, 4-77%, 8-69% and 4-73% of OC for the five sampling sites ZQ, DZ, XH, WH and SK, respectively. From the temporal and spatial variation analysis of major species, coal combustion, agricultural residual burning and industrial emission including dust re-suspended from raw material storage piles were important sources for atmospheric PM(10) in Fushun at heating, non-heating and sand periods, respectively. It was confirmed by principal component analysis that coal combustion, vehicle emission, industrial activities, soil dust, cement and construction dust and biomass burning were the main sources for PM(10) in this coal-based city.
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http://dx.doi.org/10.1039/c2em10648eDOI Listing
March 2012

Risk assessment of heavy metals in road and soil dusts within PM2.5, PM10 and PM100 fractions in Dongying city, Shandong Province, China.

J Environ Monit 2012 Mar 12;14(3):791-803. Epub 2012 Jan 12.

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Weijin Road 94 #, Tianjin, China 300071.

15 road and 14 soil dust samples were collected from an oilfield city, Dongying, from 11/2009-4/2010 and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) for V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb within PM(2.5), PM(10) and PM(100) fractions synchronously. Metal concentrations, sources and human health risk were studied. Results showed that both soil and road dust exhibited higher values for Mn and Zn and lower values for Co and Cd for the three fractions. Mass concentration ratios of PM(2.5)/PM(10) and PM(10)/PM(100) for metals in road and soil dust indicate that most of the heavy metals tend to concentrate in fine particles. Geoaccumulation index and enrichment factors analysis showed that Cu, Zn and Cd exhibited moderate or heavy contamination and significant enrichment, indicating the influence of anthropogenic sources. Vanadium, Cr, Mn and Co were mostly not enriched and were mainly influenced by crustal sources. For Ni, As and Pb, they ranged from not enriched to moderately enriched and were influenced by both crustal materials and anthropogenic sources. The conclusions were confirmed by multivariate analysis methods. Principle component analysis revealed that the major sources were vehicle emission, industrial activities, coal combustion, agricultural activities and crustal materials. The risk assessment results indicated that metal ingestion appeared to be the main exposure route followed by dermal contact. The most likely cause for cancer and other health risks are both the fine particles of soil and road dusts.
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http://dx.doi.org/10.1039/c1em10555hDOI Listing
March 2012

A land use regression model incorporating data on industrial point source pollution.

J Environ Sci (China) 2012 ;24(7):1251-8

College of Urban and Environmental Science, Tianjin normal University, Tianjin 300387, China.

Advancing the understanding of the spatial aspects of air pollution in the city regional environment is an area where improved methods can be of great benefit to exposure assessment and policy support. We created land use regression (LUR) models for SO2, NO2 and PM10 for Tianjin, China. Traffic volumes, road networks, land use data, population density, meteorological conditions, physical conditions and satellite-derived greenness, brightness and wetness were used for predicting SO2, NO2 and PM10 concentrations. We incorporated data on industrial point sources to improve LUR model performance. In order to consider the impact of different sources, we calculated the PSIndex, LSIndex and area of different land use types (agricultural land, industrial land, commercial land, residential land, green space and water area) within different buffer radii (1 to 20 km). This method makes up for the lack of consideration of source impact based on the LUR model. Remote sensing-derived variables were significantly correlated with gaseous pollutant concentrations such as SO2 and NO2. R2 values of the multiple linear regression equations for SO2, NO2 and PM10 were 0.78, 0.89 and 0.84, respectively, and the RMSE values were 0.32, 0.18 and 0.21, respectively. Model predictions at validation monitoring sites went well with predictions generally within 15% of measured values. Compared to the relationship between dependent variables and simple variables (such as traffic variables or meteorological condition variables), the relationship between dependent variables and integrated variables was more consistent with a linear relationship. Such integration has a discernable influence on both the overall model prediction and health effects assessment on the spatial distribution of air pollution in the city region.
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http://dx.doi.org/10.1016/s1001-0742(11)60902-9DOI Listing
June 2013

Concentrations, spatial distributions and congener profiles of polychlorinated biphenyls in soils from a coastal city--Tianjin, China.

Chemosphere 2011 Oct 30;85(3):494-501. Epub 2011 Aug 30.

College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China.

A total of 82 surface soil samples collected from central urban sites, surrounding rural sites, coastal sites and background sites in Tianjin were analyzed for 84 PCB congeners. The mean values of total PCBs concentrations for surrounding rural sites, central urban sites, coastal sites, background sites and the whole Tianjin region were 4.45, 3.20, 12.65, 1.96 and 4.02 ng g(-1), respectively. No "urban fractionation effect" was found in Tianjin, which reflected the influence of local emission sources for PCBs such as industries and township enterprises in surrounding rural sites. In contrast, a "primary fractionation effect" was found in Tianjin region. The PCBs concentrations for whole Tianjin region showed a strong east-west gradient and the percentages of lighter molecular weight PCBs homologs (sum of di- to tetra-PCBs) to the total PCBs concentrations increased from east to west. The seven indicator PCBs concentrations were well correlated with the total PCBs concentrations with the correlation coefficients as 0.76 for Tianjin region and 0.74 for central urban sites, respectively. Predominant PCB homolog groups were penta- and tri-PCBs for Tianjin region. 10 dioxin-like PCBs concentrations were well correlated with total PCBs concentrations for all the sampling sites (R=0.79, P<0.0001). The TEQ concentrations for 10 dioxin-like PCBs were 5.3424 ng kg(-1) for Tianjin region and showed a strong east to west gradient. The spatial distribution of PCBs levels, homolog composition patterns and TEQ concentrations were all obviously influenced by local emission sources for PCBs in the east part of Tianjin region.
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http://dx.doi.org/10.1016/j.chemosphere.2011.08.010DOI Listing
October 2011

Source analysis of particulate matter associated polycyclic aromatic hydrocarbons (PAHs) in an industrial city in northeastern China.

J Environ Monit 2011 Sep 9;13(9):2597-604. Epub 2011 Aug 9.

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.

Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at eight sampling sites during cold periods where heating is used (heating period) (February to March, 2005) and warm periods where heating is not required (non-heating periods) (August to September 2006) in the urban area of Anshan, an iron and steel city in northeastern China. Eleven PAH species were measured using GC-MS. The total average concentrations of PAHs ranged from 46.14 to 385.60 ng m(-3) in the heating period and from 5.28 to 146.40 ng m(-3) in the non-heating period. The lowest concentration of ∑PAHs was observed at Qianshan, a monitoring site far from the city and industrial area, and the highest concentration occurred in the site located at the factory area of Anshan Iron and Steel Incorporation. Moreover, ambient PAH profiles were studied and high molecular weight PAH (including 4-6 rings) species occurred in the high fractions. Toxic equivalent factors analysis gave the potential carcinogenic risks in Anshan. For the heating sampling period, BaP equivalent concentration is in the range of 41.98 to 220.83 ng m(-3), and 9.23 to 126.00 ng m(-3) for the non-heating sampling period. By diagnostic ratio analysis, traffic emission and combustion (coal or biomass) were potential sources for PAHs in Anshan. Finally, PCA results indicated the major sources were vehicle emission, steel industry emission, and coal combustion for both heating and non-heating seasons, which agreed with the results from the diagnostic ratio analysis.
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http://dx.doi.org/10.1039/c1em10251fDOI Listing
September 2011

Distributions and sources of n-alkanes in PM2.5 at urban, industrial and coastal sites in Tianjin, China.

J Environ Sci (China) 2010 ;22(10):1551-7

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.

Aliphatic hydrocarbons (n-alkanes) associated with fine particulate matter were determined in the ambient air of urban, industrial and coastal areas in Tianjin, China, where intensive coal burning for industrial and domestic purpose takes place. n-Alkane homologues from C12 to C35 were quantifiable in all samples with C20-C31 being the most abundant species. Average concentrations of the total n-alkanes were 148.7, 250.1 and 842.0 ng/m3 in July, April and January, respectively. Seasonal variations were mainly attributed to ambient temperature changes and coal combustion for residential heating. Among the three studied areas, the highest levels of n-alkanes were observed in the industrial complex in winter and spring, but in summer the coastal alkane concentration moved up to the highest. A mono-modal distribution for n-alkanes was observed in spring and summer with odd carbon number predominance and a maximum centered at C27-C31, suggesting the release of plant wax into the atmosphere. The bimodal distribution with maxima at C22 and C26 observed in winter indicated a substantial influence of fossil fuel sources. All the CPIs (CPI1, CPI2, CPI3) values, varying between 0.64 and 1.97, indicated the influence of anthropogenic emissions on fine organic aerosols. The estimated contributions of plant wax to total n-alkanes were on average of 12.9%, 19.1% and 26.1% for winter, spring and summer, respectively.
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http://dx.doi.org/10.1016/s1001-0742(09)60288-6DOI Listing
February 2011

Health risk assessment of personal inhalation exposure to volatile organic compounds in Tianjin, China.

Sci Total Environ 2011 Jan;409(3):452-9

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.

Volatile Organic Compounds (VOCs) exposure can induce a range of adverse human health effects. To date, however, personal VOCs exposure and residential indoor and outdoor VOCs levels have not been well characterized in the mainland of China, less is known about health risk of personal exposure to VOCs. In this study, personal exposures for 12 participants as well as residential indoor/outdoor, workplace and in vehicle VOCs concentrations were measured simultaneously in Tianjin, China. All VOCs samples were collected using passive samplers for 5 days and were analyzed using Thermal Desorption GC-MS method. U.S. Environmental Protect Agency's Inhalation Unit Risks were used to calculate the inhalation cancer health risk. To assess uncertainty of health risk estimate, Monte Carlo simulation and sensitivity analysis were implemented. Personal exposures were greater than residential indoor exposures as expected with the exception of carbon tetrachloride. Exposure assessment showed modeled and measured concentrations are statistically linearly correlated for all VOCs (P<0.01) except chloroform, confirming that estimated personal exposure using time-weighted model can provide reasonable estimate of personal inhalation exposure to VOCs. Indoor smoking and recent renovation were identified as two major factors influencing personal exposure based on the time-activity pattern and factor analysis. According to the cancer risk analysis of personal exposure, benzene, chloroform, carbon tetrachloride and 1,3-butadiene had median upper-bound lifetime cancer risks that exceeded the U.S. EPA benchmark of 1 per one million, and benzene presented the highest median risks at about 22 per one million population. The median cumulative cancer risk of personal exposure to 5 VOCs was approximately 44 per million, followed by indoor exposure (37 per million) and in vehicle exposure (36 per million). Sensitivity analysis suggested that improving the accuracy of exposure measurement in further research would advance the health risk assessment.
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http://dx.doi.org/10.1016/j.scitotenv.2010.10.022DOI Listing
January 2011

A seasonal study of polycyclic aromatic hydrocarbons in PM(2.5) and PM(2.5-10) in five typical cities of Liaoning Province, China.

J Hazard Mater 2010 Nov 31;183(1-3):70-80. Epub 2010 Jul 31.

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Weijin Road 94#, Tianjin 300071, China.

Fourteen polycyclic aromatic hydrocarbons (PAHs) in PM(2.5) and PM(2.5-10) samples collected in five cities (Shenyang, Anshan, Jinzhou, Fushun and Dalian), Liaoning Province, China in 2004 and 2005 were analyzed by using a HPLC equipped with fluorescence and UV detectors. Results showed total PAHs concentrations in PM(2.5) and PM(2.5-10) were in the range of 75.32-1900.89 ng m(-3) and 16.74-303.24 ng m(-3), respectively. 90% of the total PAHs were in PM(2.5). PAHs in PM(2.5) had a winter to summer ratio varying from 6.5 to 125.8 while PAHs in PM(2.5-10) had a ratio ranging from 1.7 to 37.6. Total PAHs concentrations were most abundant at residential/commercial sites and were fewest at an industrial site for both PM(2.5) and PM(2.5-10). Urban background sites showed unexpected higher PAHs concentrations. Total BaP equivalent concentration (BaPeq) for PM(2.5) ranged from 7.80 to 88.42 ng m(-3) in different function zones. Similarities of PAHs profiles between sampling sites and between fine and coarse fractions were compared by coefficient of divergence which indicated that remarkable differences in PAHs compositions existed. Principal component analysis (PCA) associated with diagnostic ratios revealed coal combustion and vehicle emission were the major sources for PM(2.5) and PM(2.5-10) associated PAHs.
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http://dx.doi.org/10.1016/j.jhazmat.2010.06.107DOI Listing
November 2010

Receptor modeling of PM2.5, PM10 and TSP in different seasons and long-range transport analysis at a coastal site of Tianjin, China.

Sci Total Environ 2010 Sep 23;408(20):4681-94. Epub 2010 Jul 23.

College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, PR China.

Atmospheric particulate matter (PM(2.5), PM(10) and TSP) were sampled synchronously during three monitoring campaigns from June 2007 to February 2008 at a coastal site in TEDA of Tianjin, China. Chemical compositions including 19 elements, 6 water-solubility ions, organic and elemental carbon were determined. principle components analysis (PCA) and chemical mass balance modeling (CMB) were applied to determine the PM sources and their contributions with the assistance of NSS SO(4)(2)(-), the mass ratios of NO(3)(-) to SO(4)(2)(-) and OC to EC. Air mass backward trajectory model was compared with source apportionment results to evaluate the origin of PM. Results showed that NSS SO(4)(2)(-) values for PM(2.5) were 2147.38, 1701.26 and 239.80 ng/m(3) in summer, autumn and winter, reflecting the influence of sources from local emissions. Most of it was below zero in summer for PM(10) indicating the influence of sea salt. The ratios of NO(3)(-) to SO(4)(2)(-) was 0.19 for PM(2.5), 0.18 for PM(10) and 0.19 for TSP in winter indicating high amounts of coal consumed for heating purpose. Higher OC/EC values (mostly larger than 2.5) demonstrated that secondary organic aerosol was abundant at this site. The major sources were construction activities, road dust, vehicle emissions, marine aerosol, metal manufacturing, secondary sulfate aerosols, soil dust, biomass burning, some pharmaceutics industries and fuel-oil combustion according to PCA. Coal combustion, marine aerosol, vehicular emission and soil dust explained 5-31%, 1-13%, 13-44% and 3-46% for PM(2.5), PM(10) and TSP, respectively. Backward trajectory analysis showed air parcels originating from sea accounted for 39% in summer, while in autumn and winter the air parcels were mainly related to continental origin.
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http://dx.doi.org/10.1016/j.scitotenv.2010.06.005DOI Listing
September 2010

Characterization of PM(10) fraction of road dust for polycyclic aromatic hydrocarbons (PAHs) from Anshan, China.

J Hazard Mater 2009 Oct 21;170(2-3):934-40. Epub 2009 May 21.

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin, China.

Nineteen road dust samples were collected during 2005 in different parts of the urban area of Anshan, Liaoning Province, China, and 11 polycyclic aromatic hydrocarbons (PAHs) species were quantitatively analyzed using GC-MS. The results indicated that the total average concentration of PAHs over the investigated sites ranged from 48.73 to 638.26 microg/g, with a mean value of 144.25 microg/g, higher than the concentrations measured in previous studies. PAHs concentrations were higher with high molecular weight homologues (4-6 rings PAHs), accounting for 83.24-96.98%, showing combustion of petroleum fuels was a potential source. Organic carbon in road dust was considered one of the important factors that influenced the concentrations of PAHs in this study, and it was found that concentrations of total PAHs were correlated with those of organic carbon in road dust. The results of diagnostic ratios analysis showed traffic emission (gasoline or diesel) was one of the most important sources of road dust PAHs. Principal component analysis (PCA) indicated that the major sources of road dust PAHs might be emission from traffic, steel industry, cooking and coal combustion.
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http://dx.doi.org/10.1016/j.jhazmat.2009.05.059DOI Listing
October 2009

Quantitative health risk assessment of inhalation exposure to polycyclic aromatic hydrocarbons on citizens in Tianjin, China.

Bull Environ Contam Toxicol 2009 Aug 17;83(2):151-4. Epub 2009 Mar 17.

State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, 300071, Tianjin, China.

Considering the large amounts of PAHs emitted into the ambient air in China, it is urgent to take preliminary health risk assessment of citizens through inhalation exposure to PAHs in China. The incremental lifetime cancer risk (ILCR) model was used to get the risk level of Tianjin citizens as an example, and Monte Carlo simulation was adopted to deal with the uncertainty. Exposure analysis found that the average values of B[a]P equivalent (B[a]Peq) daily exposure doses for children in the indoor, traffic and outdoor settings were estimated to be 2,446.8, 478.4, and 321.6 ng day(-1), respectively. And those for adults were 3,344.1, 794.9, and 519.0 ng day(-1), respectively. Much attention must be paid to indoor exposure, as it contributes more than 70% of the B[a]Peq daily exposure dose. ILCR falls within the range of 10(-5)-10(-3), which is higher than the acceptable risk level of 10(-6), and lower than the priority risk level (10(-3)). So this risk should be compared with those of other public health issues in the purpose of risk management. Sensitivity analysis found that the two variables, indoor air PAHs concentration distribution and the cancer slope factor (CSF) of BaP, contribute about 89% of the total risk uncertainty. Thus they are considered as the two main factors influencing the accuracy of the PAHs health risk assessment.
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http://dx.doi.org/10.1007/s00128-009-9686-8DOI Listing
August 2009