The associations of air pollution exposure during pregnancy with fetal growth and anthropometric measurements at birth: a systematic review and meta-analysis

Environmental Science and Pollution Research - Fetal growth has been demonstrated to be an important predictor of perinatal and postnatal health. Although the effects of maternal exposure to air...     

我国农药工业三废治理方法

详细介绍了我国农药生产中排放的废水、废气、废渣的常用治理技术,通过改进生产工艺和回收利用减少三废的实例,以及主要品系农药生产废水治理方法选择的思路。     

Environmentally Friendly Oil-Modified Polyesters as Polymeric Plasticizers for Poly(vinyl chloride)

Oil-modified polyesters were synthesized to serve as polymeric plasticizers for PVC. A total of four polymeric plasticizers with different average molecular weights were prepared. Characterizations were done using Fourier-transformed infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. Some of the tests conducted on PVC films include thermal stability test using thermogravimetric analyser, determination of glass transition temperature (T_g), plasticizer migration and leaching resistance test, morphology study of plasticized PVC films using field emission scanning microscope, toxicity test, and tensile test. Owing to the plasticizing effect of the palm oil-based compound, T_g of the plasticized PVC has decreased to an average of 65 °C at 20 wt% loading. The polymeric plasticizer is also able to contribute positively to the thermal stability and mechanical properties of the PVC films. Some of the advantages of incorporating polymeric plasticizer with high molecular weight includes lower rate of leaching from plastic, and improved tensile strength and elongation at break. Besides, thermal stability of the plastic studied using Kissinger’s and Flynn–Wall–Ozawa’s approaches shows that PVC blended with high molecular weight oil-modified polyester is more thermally stable, evidenced by the increase in the activation energy of decomposition, E_d. Toxicity test using brine shrimp egg shows encouraging results, where the oil-based plasticizer is considerably less toxic compared to some of the commercial plasticizers.     

苏丹红I对小鼠卵巢的损伤作用及对Caspase-3和Ki-67表达的影响

苏丹红是一种人工合成偶氮染料,可引起肝脏及泌尿系统等多个脏器的肿瘤,但苏丹红对生殖系统的毒性研究较少。本研究以昆明小鼠为受试对象,探讨苏丹红I对小鼠卵巢组织Caspase-3和Ki-67表达的影响。将24只昆明小鼠随机分为:对照组、低剂量(60 mg·kg~(-1))、中剂量(120 mg·kg~(-1))、高剂量(240 mg·kg~(-1))4组,6只/组。胃灌4周,4周末处死。HE染色观察各组卵巢组织病理变化,免疫组化法检测卵巢组织Caspase-3和Ki-67表达,Real time PCR检测卵巢组织Caspase-3和Ki-67 m RNA表达,Western blotting检测卵巢组织中Ki-67及Caspase-3蛋白表达。与对照组比较,实验组卵巢中Caspase-3阳性细胞率显著升高(P0.05),而Ki-67阳性细胞率显著降低(P0.05),Real time PCR及Western blotting结果与免疫组化法结果一致。本实验发现苏丹红染毒后颗粒细胞的Caspase-3表达增加,且Caspase-3表达呈剂量依赖性,但Ki-67表达受到抑制。     

基于统计方法的辽东湾沉积物中多环芳烃来源特征分析

为研究辽东湾表层沉积物中多环芳烃(PAHs)的来源特征,2014年5月采集了20个辽东湾海域表层沉积物样品,并利用气相色谱质谱联用仪对优先控制的16种PAHs进行测定,采用聚类分析、主成分分析-多元线性回归分析、异构体比值3种统计方法对辽东湾表层沉积物中PAHs来源特征进行了研究。结果表明,辽东湾表层沉积物中PAHs含量范围88.5~199.3 ng·g-1,平均值为(126.3±35.3)ng·g-1,其中,萘、菲和荧蒽是PAHs优势组分。通过统计分析结果表明,辽东湾北部表层沉积物中PAHs含量低于西南部,沉积物中PAHs的来源包括石油燃烧来源、煤炭、木材等生物质燃烧来源和石油来源,其中燃烧来源是主要来源,煤炭、木材等生物质燃烧来源占49.9%,石油燃烧来源和石油来源占50.1%。     

Insights into the mercury(II) adsorption and binding mechanism onto several typical soils in China

To better understand the Hg(II) adsorption by some typical soils and explore the insights about the binding between Hg(II) and soils, a batch of adsorption and characteristic experiments was conducted. Results showed that Hg(II) adsorption was well fitted by the Langmuir and Freundlich. The maximum adsorption amount of cinnamon soil (2094.73 mg kg^?1) was nearly tenfold as much as that of saline soil (229.49 mg kg^?1). The specific adsorption of Hg(II) on four soil surface was confirmed by X-ray photoelectron spectroscopy (XPS) owing to the change of elemental bonding energy after adsorption. However, the specific adsorption is mainly derived from some substances in the soil. Fourier transform infrared spectroscopy (FTIR) demonstrated that multiple oxygen-containing functional groups (O–H, C=O, and C–O) were involved in the Hg(II) adsorption, and the content of oxygen functional groups determined the adsorption capacity of the soil. Meanwhile, scanning electron microscopy combined with X-ray energy dispersive spectrometer (SEM–EDS) more intuitive revealed the binding of mercury to organic matter, metal oxides, and clay minerals in the soil and fundamentally confirmed the results of XPS and FTIR to further elucidate adsorptive phenomena. The complexation with oxygen-containing functional groups and the precipitation with minerals were likely the primary mechanisms for Hg(II) adsorption on several typical soils. This study is critical in understanding the transportation of Hg(II) in different soils and discovering potential preventative measures.     

Levels,distribution profile,and risk assessment of polychlorinated biphenyls (PCBs) in water and sediment from two tributaries of the River Chenab,Pakistan

The first study aimed to investigate the polychlorinated biphenyl (PCB) concentration level, spatial distribution pattern, and ecological risk assessment of water and sediment samples from two tributaries (Nullah Aik and Palkhu) of the River Chenab, Punjab Province, Pakistan. A total of 32 PCB congeners were analyzed, and PCB concentration in sediment and water samples ranged between 0.80 and 60 ng/g and 0.20 and 28 ng/L, respectively, where tetra-CBs and tri-CBs dominated over other studied PCB homologs. Dioxin toxicity equivalency (TEQ) was calculated and PCB-126 and PCB-169 showed the higher TEQ values compared with the WHO guidelines, and sediment samples were more toxic than the water samples. The results of the present study should be considered seriously by government authorities to take a proper action against unchecked discharge of contaminants in ecological integrities; otherwise, there may be drastic results in the near future.     

柴油机微粒中可溶性有机成分的真空干燥条件

柴油机碳烟颗粒(PM)中可溶性有机组分(SOF)含量是其重要的特性参数,而真空干燥法可方便、高效、可靠地分析颗粒SOF含量,对其干燥条件的探索具有重要的研究意义和应用价值。首先采用模拟的柴油机颗粒,分析不同的干燥条件对模拟SOF(柴油、润滑油)挥发率的影响规律,得出模拟的SOF分析的最佳干燥条件;在此基础上,探索了真实柴油机颗粒SOF分析的最佳干燥条件为:干燥温度220℃、干燥时间3 h、真空度98 kPa,得知SOF组分干燥的难易程度介于柴油和润滑油之间;同时,根据此干燥条件,分析了排气管末端采集的真实碳烟颗粒的SOF含量特性。     

电渗透脱水对污泥热干燥特性的影响

以污水厂机械脱水后的污泥作为研究对象,提出了采用电渗透-热干燥结合进行深度脱水的方法。通过对原泥以及电渗透脱水至不同含水率(67%、71%和76%)的污泥在热干燥过程中含水率和干燥速率的测定,分析电渗透脱水对污泥热干燥特性的改善规律。结果表明,经电渗透脱水至含水率为67%和71%的污泥在热干燥过程中的传热传质速率及干燥速率有明显提高,且干燥温度越高,电渗透后污泥的干燥速率与原泥的干燥速率差距越大。相同电压梯度及相同温度下电渗透至67%后进行热干燥耗能最少。实际应用中应结合能耗分析选择合适的电渗透程度及干燥温度,以达到最优效果。     

Locating Spatial Variation in the Association Between Wildland Fire Risk and Social Vulnerability Across Six Southern States

Wildland fire in the South commands considerable attention, given the expanding wildland urban interface (WUI) across the region. Much of this growth is propelled by higher income retirees and others desiring natural amenity residential settings. However, population growth in the WUI increases the likelihood of wildfire fire ignition caused by people, as humans account for 93% of all wildfires fires in the South. Coexisting with newly arrived, affluent WUI populations are working class, poor or otherwise socially vulnerable populations. The latter groups typically experience greater losses from environmental disasters such as wildfire because lower income residents are less likely to have established mitigation programs in place to help absorb loss. We use geographically weighted regression to examine spatial variation in the association between social vulnerability (SOVUL) and wildfire risk. In doing so, we identify “hot spots” or geographical clusters where SOVUL varies positively with wildfire risk across six Southern states—Alabama, Arkansas, Florida, Georgia, Mississippi, and South Carolina. These clusters may or may not be located in the WUI. These hot spots are most prevalent in South Carolina and Florida. Identification of these population clusters can aid wildfire managers in deciding which communities to prioritize for mitigation programming.