Characteristics of complex air pollution in typical cities of North China

The Beijing-Tianjin-Hebei urban agglomeration is currently facing severe complex air pollution. In this paper, simultaneous observations conducted in 2014 show that the annual mean concentration of fine particulate matter （PM2.5） was 84 ± 70, 86 ±60, and 118 ± 95 μg m-3 in Beijing, Tianjin, and Shijiazhuang, respectively. The mean 03 8h max in the summer was 171 ± 43, 147 ± 45, and 146 ± 44 μg m-3, respectively. This research indicates that PM2.5 and O3 are positively correlated when the temperature exceeds 20 ℃5 and the urban agglomeration shows characteristics of complex air pollution consisting of superimposed 03 and PM2.s. In summer, when the humidity was less than 55%, secondary particles and 03 also increased in a coordinated manner （y = 1.35x ＋ 29.85; R2 = 0.61）, which demonstrates severe complex pollution. However, the mean PM2.5（y） and mean 03 8 h max （x） in summer showed a negative correlation （y = - 1.3x ＋ 245; R2 = 0.61 ） in the three regions, indicating high concentrations of PM2.5 pollution partially inhibit O3 generation.

Autotrophic Biofilters for Oxidation of Nitric Oxide

Carbon foam—a kind of new engineering material as packing material was adopted in three biofilters with different pore dimensions and adapted autotrophic nitrite nitrobacteria to investigate the purification of nitric oxide (NO) in a gas stream. The biofilm was developed on the surface of carbon foams using nitrite as its only nitric source. The moisture in the filter was maintained by ultrasonic aerosol equipment which can minimize the thickness of the liquid film. The liquid phase nitrification test was conducted to determine the variability and the potential of performance among the three carbon foam biofilters. The investigation showed that during the NO2^-—N inlet concentration of 200 g·L^-1·min^-1 to 800 g·L^-1·min^-1, the 24PPC (pores per centimeter) carbon foam biofilter had the greatest potential, achieving the NO2^-—N removal efficiency of 94% to 98%. The 8PPC and 18PPC carbon foam biofilters achieved the NO2^-—N removal efficiency of 15% to 21% and of 30% to 40%, respectively. The potential for this system to remove NO from a gas stream was shown on the basis of a steady removal efficiency of 41% to 50% which was attained for the 24PPC carbon foam biofilter at specified NO inlet concentration of 66.97 mg·m^-3 to 267.86mg·m^-3 and an empty-bed residence time of 3.5 min.

A Transition from Wood Fuel to LPG and Its Impact on Energy Conservation and Health in the Central Himalayas, India

The aim of the study was to evaluate the impacts of the transition from wood fuel to Liquefied Petroleum Gas （LPG） from energy use and health perspectives along an altitudinal gradient （viz., lower altitude; middle altitude; and higher altitude） of the Central Himalayas. Empirical field study and questionnaire based survey was conducted for obtaining the data. A total of 2o households from each altitude were selected for obtaining reliable information on the actual quantity of fuelwood consumed. Of the 2o households, five households each based on the family size i.e., small families （〈4 members）, medium （5-8 members） and large （〉9 members） from all the altitudinal regions were selected. This was followed by an administration of a questionnaire on the quantity of fuelwood consumed. After the completion of the questionnaire survey, the data was validated using a weighted survey for the randomly selected households for obtaining precise information on the actual quantity of fuelwood consumed. Energy analysis is done with respect to the time spent on fuelwood collection and energy value of burning of per kg of fuelwood. Study indicates that declining biomass requirement from forests contributes significantly towards energy conservation, also has positive impact on human health. Per capita annual energy expenditure on collection of fuelwood is 752 MJ which is higher than any other activity in villages of Central Himalaya. The LPG substitution has contributed to energy saving which is equivalent to 2976-3,742 MJ per capita per year in middle and lower altitudes respectively. In the higher altitude the energy saving is calculated to be about 257 MJ per capita per year. Replacing fuelwood with LPG has made positive impact on society in terms of improving the health while reducing diseases that are caused due to indoor air pollution.

The Study of Health Effects of Vinyl Chloride AirPollution on Population

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR),-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control,but noγ-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs

Alteration of the health effects of bioaerosols by chemical modification in the atmosphere:A review

Bioaerosols are a subset of important airborne particulates that present a substantial human health hazard due to their allergenicity and infectivity.Chemical reactions in atmospheric processes can significantly influence the health hazard presented by bioaerosols;however,few studies have summarized such alterations to bioaerosols and the mechanisms involved.In this paper,we systematically review the chemical modifications of bioaerosols and the impact on their health effects,mainly focusing on the exacerbation of allergic diseases such as asthma,rhinitis,and bronchitis.Oxidation,nitration,and oligomerization induced by hydroxyl radicals,ozone,and nitrogen dioxide are the major chemical modifications affecting bioaerosols,all of which can aggravate allergenicity mainly through immunoglobulin E pathways.Such processes can even interact with climate change including the greenhouse effect,suggesting the importance of bioaerosols in the future implementation of carbon neutralization strategies.In summary,the chemical modification of bioaerosols and the subsequent impact on health hazards indicate that the combined management of both chemical and biological components is required to mitigate the health hazards of particulate air pollution.

Compositional characteristics and toxicological responses of human lung epithelial cells to inhalable particles (PM_(10)) from ten typical biomass fuel combustions

As the primary component of haze,atmospheric inhalable particulate matters(PMio)are highly detri-mental to human health.Biomass combustion is one of China's most pivotal sources to aerosols pollution,inducing non-negligible emissions and uncertain risks.PMio samples directly from 10 representative biomass fuel combustion sources(2 groups covering the reality widely:straws of rice,wheat,corn,corncob,soybean,peanut,rape,sesame;and branches of pine,peach)were collected using the dilution channel sampler and analyzed for chemical compositions and in vitro cytotoxicity to human lung epithelial cell lines A549.The components of PMio are dominated by organic carbon(OC),followed by Water-soluble K+and Cl,and rich in metals Fe,Zn,Cr,and Ni.Generally,PMio emitted from biomass fuel combustions can weaken the antioxidant capacity of cells,and straws emissions,especially rape and peanut straws,show stronger ability to further induce oxidative stress and inflammatory damage than fuelwoods,owing to the key toxic roles of Cr,Ni,and Co.Therefore,reducing the specific source emis--sions of PMio from crop straw combustions rich in heavy metals could be an effective oriented strategy to improve environmental air quality and control aerosols pollution precisely for protecting public health.

Microbial aerosol characteristics in highly polluted and nearpristine environments featuring different climatic conditions

There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable （fluorescent） bioaerosol concentration levels at city centers （highly polluted） and their corresponding suburbs （near pristine） （total 40 locations） in 11 provinces featuring different climate zones in China between July 16 and 28, 2013. The concentration levels of viable bioaerosol particles （BioPM） of 〉0.5 μm were measured, and corresponding percentages of BioPM% （biological fraction of total PM） and BioPM2.5% （biological fraction of PM2.5） in particulate matter （PM） and BioPM, respectively, were determined. For some key cities, indoor viable bioaerosol levels were also obtained. In addition, bacterial structures of the air samples collected across these monitoring locations were studied using pyrosequencing. BioPM concentration levels ranged from 2.1 ×10^4 to 2.4 × 10^5/m3 for city centers [BioPM% = 6.4 % （4-6.3 %）] and 0.5 × 10^4 to 4.7 × 10^5/m3 for suburbs [BioPM% = 10 % （4-8.7 %）]. Distinctive bioaerosol size distribution patterns were observed for different climate zones, e.g., some had fluorescence peaks at 3 μm, while the majority had peaks at 1 μm. Ambient bacterial aerosol community structures were also found different for different geophysical locations. Results suggest that there was a poor overall relationship between PM and BioPM across 40 monitoring locations （R2= 0.081, two-tailed P value = 0.07435）. Generally, city centers had higher PM concentrations than suburbs, but not BioPM and BioPM%. Indoor bioaerosol levels were found at least tenfold higher than those corresponding outdoors. Bacillus was observed to dominate the bacterial aerosol community in the air sample.

Development of an integrated policy making tool for assessing air quality and human health benefits of air pollution control

Efficient air quality management is critical to protect public health from the adverse impacts of air pollution. To evaluate the effectiveness of air pollution control strategies, the US Environmental Protection Agency （US EPA） has developed the Software for Model Attainment Test-Community Edition （SMAT-CE） to assess the air quality attainment of emission reductions, and the Environmental Benefits Mapping and Analysis Program- Community Edition （BenMAP-CE） to evaluate the health and economic benefits of air quality improvement respectively. Since scientific decision-making requires timely and coherent information, developing the linkage between SMAT-CE and BenMAP-CE into an integrated assessment platform is desirable. To address this need, a new module linking SMAT-CE to BenMAP-CE has been developed and tested. The new module streamlines the assessment of air quality and human health benefits for a proposed air pollution control strategy. It also implements an optimized data gridding algorithm which significantly enhances the computational efficiency without compro- mising accuracy. The performance of the integrated software package is demonstrated through a case study that evaluates the air quality and associated economic benefits of a national-level control strategy of PM2.5. The results of the case study show that the proposed emission reduction reduces the number of nonattainment sites from 379 to 25 based on the US National Ambient Air Quality Standards, leading to more than USS334billion ofeconomic benefits annually from improved public health. The integration of the science-based software tools in this study enhances the efficiency of developing effective and optimized emission control strategies for policy makers.