[Emission Characteristics of Gas-and Particle-Phase Polycyclic Aromatic Hydrocarbons from Cooking].

Polycyclic aromatic hydrocarbons (PAHs) play a key role in the formation of secondary organic areole and ozone. This study sampled three commercial Chinese restaurants and a food plant in Shenzhen to analyze the emission characteristics of PAHs, especially the alkyl PAHs in both gas and particle phases. The results showed that the ρ(total PAHs)in the particle and gas phase were (1381.6±140.5) ng·m-3, (1030.2±116.4) ng·m-3, (908.3±111.9) ng·m-3, and (838.0±93.5) ng·m-3 in the food plant, Sichuan, Cantonese, and Zhejiang restaurants, respectively. More than 60% of the PAHs were distributed in the gas phase, especially the lower molecular weight PAHs (lower than Chrysene). The gas phase proportion of naphthalene was the highest, with over 75% of it distributed in the gas phase. However, the PAHs with a higher molecular weight than that of benzo(b)fluorescence were mainly distributed in the particle phase. The total concentration of alkyl PAHs emitted from cooking was much lower than that of the corresponding parent PAHs, and the distribution characteristics of alkyl PAHs were quite different from those of other emission sources. The linear fitting of lgKp and lgPL showed that the slopes of the three commercial restaurants ranged from -0.25 to -0.28, whereas for the food plant, the value was -0.18, which indicates that the gas-particle partitioning of PAHs were not in equilibrium.

[Review of Screening and Applications of Organic Tracers in Fine Particulate Matter].

Specific organic compounds within atmospheric particulate matter are indicators of specific pollution sources and, as such, can be used to differentiate inputs from various air pollution emissions sources in urban areas. Therefore, many studies have been conducted to detect organic particulate matter and screen the associated organic tracers that provide provenance information. This review provides a brief summary of the emission characteristics of biomass burning, cooking, fossil fuel combustion, and traffic. The particular marker compounds that carry provenance information for these four emission sources are discussed and diagnostic ratios are calculated to discuss the use of organic tracers in source apportionment. The shortcomings and new directions of using source tracer screening are also discussed.

Chemical characterization of particulate organic matter from commercial restaurants: Alkyl PAHs as new tracers for cooking.

Cooking is one of the primary sources of particulate organic matter (POM) in urban environments. Numerous experiments have been performed to investigate the composition of POM generated during cooking. However, there still remain substantial uncertainties in our knowledge regarding the emission characteristics of alkyl polycyclic aromatic hydrocarbons (PAHs) from cooking. In addition, previous studies have selected several tracers for Chinese cooking; however, these results were acquired based on observations in the Pearl River Delta region of China, and only four of the eight Chinese cooking styles were tested. Therefore, the organic compositions of the PM2.5 emitted from four Chinese cooking restaurants in different cities are examined to investigate the emission characteristics of alkyl PAH and to verify whether the selected tracers vary with geographical location and cooking styles. In this study, C1- and C2-phenanthrenes/anthracenes, and C1-pyrenes were detected in the PM2.5 from the four tested restaurants, but the concentrations of these PAH alkyl homologues were all at low levels, and also much lower than the corresponding parent PAHs. However, the distribution pattern of the alkyl PAHs in the cooking fumes was significantly different from that in the PM from other emission sources. Additionally, some candidate tracers for cooking such as levoglucosan were less influenced by cooking styles or geographical location. Thus, these alkyl PAHs in conjunction with other specific tracers for cooking were utilized to estimate the contribution of cooking to ambient organic carbon. The results showed that the estimates from the chemical mass balance model that includes alkyl PAHs will be higher than the model that does not, and in the case of high alkyl PAHs ambient concentrations, the model that includes alkyl PAHs will provide more reasonable results.

[Emission Characteristics of Particulate Organic Matter from Cooking].

Cooking is an important source of atmospheric particulate organic matter (POM). In this study, four Chinese restaurants in Shenzhen (west style, dim-sim restaurant, worker's canteen, and Korean cuisine) were sampled to examine the chemical composition of POM and research molecular tracers. The result showed that more than 60% of the PM2.5 mass was due to organic compounds. For the quantified organic compounds, the results indicated that fatty acids, dicarboxylic acids, and n-alkanes were the major organic compounds emitted from all cooking styles, PAHs, sterols, and monosaccharide anhydrides were found at relatively low levels. The composition of POM was strongly influenced by cooking style. The cooking styles of the west and Korean restaurant emitted the most abundant fatty acids, n-alkanes, and PAHs, but the least sterols and monosaccharide anhydrides, whereas the dim-sim restaurant and worker's canteen displayed the opposite results. The values of Fla/(Fla+Pyr) and LG/(Gal+Man) provided candidate tracers for cooking because they were less influenced by the cooking styles and were significantly different from other pollutant sources. Furthermore, cooking contributed significant amounts of fatty acids and dicarboxylic acids to atmospheric PM in Shenzhen.

Establishment of stream nutrient criteria by comparing reference conditions with ecological thresholds in a typical eutrophic lake basin.

The establishment of numeric nutrient criteria is essential to aid the control of nutrient pollution and for protecting and restoring healthy ecological conditions. However, it's necessary to determine whether regional nutrient criteria can be defined in stream ecosystems with a poor ecological status. A database of periphytic diatom samples was collected in July and August 2011 and 2012. In total 172 samples were included in the database with matching environmental variables. Here, percentile estimates, nonparametric change-point analysis (nCPA) and Threshold Indicator Taxa ANalysis (TITAN) were conducted to detect the reference conditions and ecological thresholds along a total nitrogen (TN) and total phosphorus (TP) gradient and ammonia nitrogen (NH3-N) for the development of nutrient criteria in the streams of the Lake Dianchi basin. The results highlighted the possibility of establishing regional criteria for nutrient concentrations, which we recommended to be no more than 1.39 mg L-1 for TN, 0.04 mg L-1 for TP and 0.17 mg L-1 for NH3-N to prevent nuisance growths of tolerant taxa, and 0.38 mg L-1 for TN, 0.02 mg L-1 for TP and 0.02 mg L-1 for NH3-N to maintain high quality waters in streams. Additionally, the influence of excessive background nutrient enrichment on the threshold response, and the ecological interaction with other stressors (HQI, etc.) in the nutrient dynamic process need to be considered to establish the eventual nutrient criteria, regardless of which technique is applied.

Projections of NH3 emissions from manure generated by livestock production in China to 2030 under six mitigation scenarios.

China's rapid urbanization, large population, and increasing consumption of calorie-and meat-intensive diets, have resulted in China becoming the world's largest source of ammonia (NH3) emissions from livestock production. This is the first study to use provincial, condition-specific emission factors based on most recently available studies on Chinese manure management and environmental conditions. The estimated NH3 emission temporal trends and spatial patterns are interpreted in relation to government policies affecting livestock production. Scenario analysis is used to project emissions and estimate mitigation potential of NH3 emissions, to year 2030. We produce a 1km×1km gridded NH3 emission inventory for 2008 based on county-level activity data, which can help identify locations of highest NH3 emissions. The total NH3 emissions from manure generated by livestock production in 2008 were 7.3TgNH3·yr-1 (interquartile range from 6.1 to 8.6TgNH3·yr-1), and the major sources were poultry (29.9%), pigs (28.4%), other cattle (27.9%), and dairy cattle (7.0%), while sheep and goats (3.6%), donkeys (1.3%), horses (1.2%), and mules (0.7%) had smaller contributions. From 1978 to 2008, annual NH3 emissions fluctuated with two peaks (1996 and 2006), and total emissions increased from 2.2 to 7.3Tg·yr-1 increasing on average 4.4%·yr-1. Under a business-as-usual (BAU) scenario, NH3 emissions in 2030 are expected to be 13.9TgNH3·yr-1 (11.5-16.3TgNH3·yr-1). Under mitigation scenarios, the projected emissions could be reduced by 18.9-37.3% compared to 2030 BAU emissions. This study improves our understanding of NH3 emissions from livestock production, which is needed to guide stakeholders and policymakers to make well informed mitigation decisions for NH3 emissions from livestock production at the country and regional levels.

Bacterioplankton community responses to key environmental variables in plateau freshwater lake ecosystems: A structural equation modeling and change point analysis.

Elevated environmental pressures negatively affect the bacterial community structure. However, little knowledge about the nonlinear responses of spatially related environmental variable across multiple plateau lake ecosystems on bacterioplankton communities has been gathered. Here, we used 454 pyrosequencing of 16S rRNA genes to study the associations of bacterial communities in terms of environmental characteristics as well as the potentially ecological threshold-inducing shifts of the bacterial community structure along the key environmental variables based on hypothesized structural equation models and the SEGMENTED method in 21 plateau lakes. Our results showed that water transparency was the major driving force and that total nitrogen was more significant than total phosphorus in determining the taxon composition of the bacterioplankton community. Significant community threshold estimates for bacterioplankton were observed at 7.36 for pH and 25.6% for the percentage of the agricultural area, while the remarkable change point of the cyanobacteria community structure responding to pH was at 7.74. Furthermore, the findings indicated that increasing nutrient loads can induce a distinct shift in dominance from Proteobacteria to Cyanobacteria, as well as a sharp decrease and adjacent increase when crossing the change point for Actinobacteria and Bacteroidetes along the gradient of the agricultural area.

Design and characterization of human exposure to generated sulfate and soot particles in a pilot chamber study.

UNLABELLED: A number of literatures have documented adverse health effects of exposure to fine particulate matter (PM2.5), and secondary sulfate aerosol and black carbon may contribute to health impacts of PM2.5 exposure. We designed an exposure system to generate sulfate and traffic soot particles, and assessed the feasibility of using it for human exposure assessment in a pilot human exposure study. In the designed exposure system, average mass concentrations of generated sulfate and soot particles were 74.19 µg/m3 and 11.54 µg/m3 in the chamber and did not vary significantly during two-hour human exposure sessions. The size ranges of generated sulfate were largely between 20 to 200 nm, whereas those of generated soot particles were in the size ranges of 50 to 200 nm. Following two-hour exposure to generated sulfate and soot particles, we observed significant increases in fractional exhaled NO (FeNO) in young and health subjects. Building on established human exposure system and health response follow-up methods, future full-scale studies focusing on the effects of mixed particulates and individual PM2.5 components would provide data in understanding the underpinning cardio-respiratory outcomes in relation to air pollution mixture exposure. IMPLICATIONS: Controlled exposure is a useful design to measure the biological responses repeatedly following particulate exposures of target components and set exposure at target levels of health concerns. Our study provides rational and establishes method for future full-scale studies to focus on examining the effects of mixed particulates and individual PM2.5 components.

Increasing eutrophication in the coastal seas of China from 1970 to 2050.

We analyzed the potential for eutrophication in major seas around China: the Bohai Gulf, Yellow Sea and South China Sea. We model the riverine inputs of nitrogen (N), phosphorus (P) and silica (Si) to coastal seas from 1970 to 2050. Between 1970 and 2000 dissolved N and P inputs to the three seas increased by a factor of 2-5. In contrast, inputs of particulate N and P and dissolved Si, decreased due to damming of rivers. Between 2000 and 2050, the total N and P inputs increase further by 30-200%. Sewage is the dominant source of dissolved N and P in the Bohai Gulf, while agriculture is the primary source in the other seas. In the future, the ratios of Si to N and P decrease, which increases the risk of harmful algal blooms. Sewage treatment may reduce this risk in the Bohai Gulf, and agricultural management in the other seas.

Synthesis and investigation of the imprinting efficiency of ion imprinted nanoparticles for recognizing copper.

The Cu(2+) imprinted nanoparticles were synthesized using a simple approach including imprinting and crosslinking in aqueous solutions. The morphologies of imprinted polymers were alterable by changing the component ratio and are illustrated using a field emission scanning electron microscope. The obtained nanoparticles were applied as novel polymeric adsorbents with outstanding adsorption capacity and good selectivity to recognize and remove copper ions. The component ratio of PEI, crosslinking agents and template ions was systematically studied with their influence on the morphology and imprinting efficiency of sorbents. The crosslinking degree and the amount of imprinted sites were investigated with different component ratios and were confirmed to be the key factors of the imprinting efficiency. The appropriate dosage ratio of PEI, ECHA and template Cu(2+) was 1 g : 1 g : 2.5 mmol and the imprinting efficiency can be significantly improved. The maximum selectivity coefficients of the nanoparticles for Cu(2+)/Cr(3+) and Cu(2+)/Zn(2+) were 5.21 and 21.00. The results obtained could be extended to other polymers with improvement in imprinting efficiency and further applications.

Culturable diversity and biochemical features of thraustochytrids from coastal waters of Southern China.

Thraustochytrids are ubiquitous marine osmo-heterotrophic fungi-like microorganisms with only about 40 identified species till now. In this study, a total of 60 thraustochytrid strains were isolated from marine coastal habitats. Analysis of 18S rRNA gene sequences revealed that they belonged to three genera, i.e., Schizochytrium, Aurantiochytrium, and Thraustochytrium. All of the isolates were found to show considerable cellulolytic and lipolytic activities. Strains of Aurantiochytrium sp. and Thraustochytrium sp. were found to produce the highest levels of extracellular polysaccharides (EPS), which reached 345 µg ml(-1) in the growth media. Fourier transform infrared (FTIR) spectra of the EPS samples derived from two thraustochytrids (PKU#Sed1 and #SW1) displayed peaks for carbohydrates, proteins, lipids, uronic acids, and nucleic acids. Fatty acid profiles of four thraustochytrids comprised of palmitic acid (C16:0) and docosahexaenoic acid (DHA) as their major constituents. Schizochytrium sp. demonstrated the highest DHA production at 44 % of total fatty acids (TFA) with biomass and DHA yield of 7.1 and 1.6 g l(-1), respectively, on the fourth day of growth. All the four isolates exhibited considerable production of palmitic acid (16:0) in their fatty acid profiles ranging from 35 to 50 % TFA. This is the first report on extracellular enzymes, EPS, and DHA production from thraustochytrids isolated from the coastal habitats of China.

[Pollution characteristics and health assessment of particulate mercury in Hebei rural households].

Environment problems in rural areas have been increasing dramatically in recent years. Atmospheric particulate mercury has posed increasingly obvious threats to human health. However, there were few studies attaching importance on mercury pollution in rural residential environment. Taking particulate mercury as research objects, the studies in six villages of Hebei Province were carried out in July/August 2009 and October/September 2010. A number of PM10 and PM2.5 samples were taken in 34 typical households, using cold vapor atomic fluorescence to determine the content of particulate mercury. The results showed that the mercury concentration in PM10 in kitchen was about twice that in the courtyard. In the same space, the mercury contents in PM10 in a descending order were as follows: winter (3.004 ng x m(-3)), autumn (1.550 ng x m(-3)), summer (1.127 ng x m(-3)); in the same season, the mercury levels in PM2.5 in a descending order were as follows: kitchen (0.795 ng x m(-3) +/- 0.337 ng x m(-3)), living room (0.398 ngx m(-3) +/- 0.159 ng x m(-3)), yard (0.321 ng x m(-3) +/- 0.143 ng x m(-3)); the Mercury content in PM2.5 accounted for (52.4 +/- 13.5)% of that in PM10. Evaluation of the health risks of mercury in PM2.5 revealed that children were exposed to the highest level, whose average annual excess risk was below 10(-8). Therefore, the health risk of peasants living in rural residential environment was at a negligible level.

[Hourly measurement on aerosol NH3 and gas NO(x) emission in the rice field].

Aerosol NH3 and gas NO(x) are the major components in atmospheric particles and precipitation, which are key precursors to form aerosols. The intensive N fertilization in arable land is an important source of aerosol NH3 and gas NO(x), which have not been well characterized yet. During May to October in 2010, the characteristics of aerosol NH3 and gas NO(x) emission from rice field after urea application were investigated. The time resolutions of measurements were set to be one hour. The aerosol NH3 emission and metrological factors within 20 d of continuous sampling after fertilization in four experiments were monitored. The experiment on gas NO(x) emission and metrological factors influencing the emission were carried out from the beginning of the forth test, which lasted for 47 days. Results indicated that the aerosol NH3 emission factors of four tests were 2.6%, 5.5%, 4.0% and 1.6%, respectively. The corresponding aerosol NH3 emission flux of four tests were 3.97, 2.08, 1.52 and 1.22 kg x hm(-2), respectively. Temperature (air temperature and soil temperature) was found to be the main factor influencing aerosol NH3 emission in rice fields after fertilization, while the impacts of air humidity and soil moisture were not clear. After analyzing the monitoring data, it can be concluded that the ratio of the emission amount of NO2 -N and NO-N in rice fields after fertilization was 9/4; the emission factor and the emission flux of gas NO(x) were 0.14% and 0.30 kg x hm(-2), respectively. The relationship between metrological factors and gas NO(x) emission flux was also examined.

[In-situ measurement on volatilization loss of ammonia in the vegetable field and its influencing factors].

In order to obtain ammonia volatilization flux and volatilization loss rate in the vegetable field and investigate their relationship with environmental factors, an on-line monitoring system was used to measure the ammonia volatilization in the vegetable (Brassica rapa L. and lettuce) field after urea application during January to September, 2009. The system included a wind tunnel system, a gas collector and an online analyzer system with ion chromatography. The time resolution of measurement was 15 min. The recovery of the system was (92.6 +/- 3.4)%; the accumulated ammonia volatilization within 15 d continuous sampling after fertilization was regarded as the total loss. The accumulated ammonia volatilization of 12 d continuous sampling after fertilization accounted for (85.4 +/- 5.2)% of the total volatilization. The ammonia volatilization loss of broadcasting basal dressing and top dressing for Brassica rapa L. were 23.6% and 21.3%, respectively. The ammonia volatilization loss of holing basal dressing and top dressing for lettuce were 17.6% and 24.0%, respectively. The ammonia volatilization in the vegetable field mostly occurred in the first 2-3 weeks after fertilization. The ammonia volatilization flux had significant positive correlation with the nitrogen application rate, while the ammonia volatilization loss rate had negative correlation with the nitrogen application rate. The ammonia volatilization flux was positively correlated with the soil temperature (r = 0.041, p < 0.05) and the air temperature (r = 0.049, p < 0.01), while not significantly associated with the air humidity and the soil moisture. Temperature was found to be a main factor influencing the ammonia volatilization in the vegetable field.

Estimating the volatilization of ammonia from synthetic nitrogenous fertilizers used in China.

Although it has long been recognized that significant amounts of nitrogen, typically in the form of ammonia (NH(3)) applied as fertilizer, are lost to the atmosphere, accurate estimates are lacking for many locations. In this study, a detailed, bottom-up method for estimating NH(3) emissions from synthetic fertilizers in China was used. The total amount emitted in 2005 in China was estimated to be 3.55 Tg NH(3)-N, with an uncertainty of ± 50%. This estimate was considerably lower than previously published values. Emissions from urea and ammonium bicarbonate accounted for 64.3% and 26.5%, respectively, of the 2005 total. The NH(3) emission inventory incorporated 2448 county-level data points, categorized on a monthly basis, and was developed with more accurate activity levels and emission factors than had been used in previous assessments. There was considerable variability in the emissions within a province. The NH(3) emissions generally peaked in the spring and summer, accounting for 30.1% and 48.8%, respectively, of total emissions in 2005. The peaks correlated with crop planting and fertilization schedules. The NH(3) regional distribution pattern showed strong correspondence with planting techniques and local arable land areas. The regions with the highest atmospheric losses are located in eastern China, especially the North China Plain and the Taihu region.

[Validation of a prediction method for indoor air pollution].

The validation study of the prediction method for indoor air pollution was carried out by comparing the results of emission models based on data obtained in a large and a small emission chamber, with actual measured concentrations. A new decorated room was studied as a case. Emissions of complicated objects and simple surface layer materials were studied respectively in the large and small chamber and emission models were developed. Those models were based on the assumptions regarding mass conservation of substances and the hypothesis that pollutants were well mixed. The emissions of formaldehyde and TVOC (total volatile organic compounds) in the studied room were predicted by the method. The predicted concentration trend of pollutants was in accordance with the measured trend when some air exchange (0.03 ACH, air change per hour) was taken into account. The normalized standard errors of formaldehyde and TVOC pollution prediction were respectively 2.8% and 1.6%. Modeling analysis shows that the contribution to total formaldehyde pollution of the studied room was: furniture > paint > floor; the contribution to total TVOC pollution was: paint > floor > furniture. The results lead to the conclusion that this prediction method can well describe the pollution trend, can assess the contribution of different sources, can guide the choice of building materials and is an effective tool for indoor air pollution assessment and control.

Uptake and biodegradation of DDT by 4 ectomycorrhizal fungi.

This research deals with biodegradation of 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) by 4 selected ectomycorrhizal fungi (ECMF) species, Boletus edulis, Gomphidius viscidus, Laccaria bicolor, and Leccinum scabrum. The pure culture of the four ECMF species in a DDT environment (5 mg/l) showed that DDT almost completely disappeared from the media after 15 days, but only 40-50% was found being accumulated in mycelia. Further gas chromatography mass spectrometry (GC-MS) test of the hexane extractable metabolites identified that the remaining DDT degraded to 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD) (retention time 17.39 min) and 4,4'-dihlorobenzophenone (DBP) (retention time 14.89 min). Therefore, these results, for the first time, demonstrated that ECMF can degrade DDT through a similar pathway found in white rot fungi.

Approach to and effectiveness of environmental risk education of public: case of indoor environmental risk consciousness in beijing.

Increasing concern regarding environmental risk in China has led to a need for education on environmental health and safety. In this paper, we report on four main ways to enhance environmental risk consciousness of the public. By investigating residents' indoor environmental risk consciousness in Beijing, we appraised the effectiveness of current environmental risk education approaches. Our investigation showed that the indoor environmental risk consciousness of most residents is high. Most residents have some environmental risk knowledge, have a strong desire to demand better quality of their living environment, and would like to invest in it. However, people's actual behavior in terms of reducing health risk factors fall comparatively behind. It is important to use all approaches to carry out environmental risk education. Not only should new knowledge be imparted, but the public should also be trained how to take precautions against pollution. The extension of education from campus to society is also necessary.