Meta-analysis of the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts in China

To investigate the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts of the workers, domestic and foreign published research data on the change of human peripheral blood leukocyte counts under low-level occupational benzene exposure from January 1990 to December 2020 were collected and analyzed. According to the literature inclusion and exclusion criteria, 18 independent studies from 12 publications were selected for meta-analysis to explore the effect ...     

Effect of coumaphos on cholinesterase activity,hematology, and biochemical blood parameters of bovines in tropical regions of Mexico

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg^{? 1} body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = ? 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = ? 0.883, p = 0.020) and lymphocyte (r = ? 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = ?0.998, p = 0.043), absolute red blood cell (r = ? 0.998, p = 0.040), lymphocyte (r = ? 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).     

Maternal exposure to high levels of dioxins in relation to birth weight in women affected by Yusho disease

Background

Studies on the association of maternal exposure to polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease.

Objective

The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight.

Methods

Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non-ortho PCBs.

Results

Total PCDD TEQ (adjusted beta = − 161.9 g; 95% CI, −265.3 to − 58.6), total PCDF TEQ (adjusted beta = − 105.9 g; 95% CI, −179.5 to − 32.2), and total non-ortho PCBs (adjusted beta = − 178.4 g; 95% CI, −318.3 to − 38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non-ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF.

Conclusion

In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.     

Comparison of the concentrations of polychlorinated biphenyls and dioxins in mothers affected by the Yusho incident and their children

Accumulated maternal dioxins are passed onto the fetus and neonate via the placenta and maternal milk. In Japan in 1968, an accidental human exposure to rice oil contaminated with polychlorinated biphenyls (PCBs) and other dioxin-related compounds, such as polychlorinated dibenzofurans (PCDFs), led to development of Yusho oil disease. We investigated differences in blood dioxin concentrations in mother-children pairs affected by the Yusho incident. From 2002 to 2008, blood samples were collected from 26 pairs of Yusho mothers and their children (19 mothers, 26 children). Specific congeners of seven polychlorinated dibenzo-p-dioxins (PCDDs), ten PCDFs, and four non-ortho PCBs were analyzed. The children had significantly lower TEQ concentrations of PCDDs, PCDFs, and coplanar PCBs compared to their mothers. The mother-child difference in blood concentrations varied with the congeners; the largest for 2,3,4,7,8-pentaCDF and the smallest for 1,2,3,4,6,7,8-heptaCDD. The level for 2,3,4,7,8-pentaCDF, which characterizes Yusho oil disease, was approximately 17-30 times higher in the mothers than in the general population, whereas there were no significant differences between children in the formula-fed group and the general population. In contrast, the mean level for 2,3,4,7,8-pentaCDF in the breast-fed group was approximately 1.5 times, (range 0.5-6.5 times) higher than that in the general population. Over 30 years after the Yusho incident, the mean blood dioxin levels in the offspring were only a fraction of the levels in their mothers. This is more consistent with exposure via breast milk than via transplacental transfer in the Yusho incident.     

含油污泥中不同族组分的脱附特性研究

针对含油污泥的热水脱附处理方法,在优化脱附工艺条件下,研究不同单组分脱附剂对含油污泥中各族组分的脱附特性,并据此复配脱附剂,研究各复配脱附剂对含油污泥中不同族组分的脱附特性.结果表明,聚氧乙烯型非离子表面活性剂对含油污泥的脱附效率优于多元醇型非离子表面活性剂; 各脱附剂对饱和烃、芳烃的脱附效率高于对胶质沥青质的脱附效率; 带脂肪链的脱附剂对饱和烃的脱附效率较高,带苯环的脱附剂对芳烃的脱附效率较高; 脱附剂亲油基与族组分的亲和性越强,脱附剂对该族组分的脱附效率越高.研究表明,根据各单组分脱附剂对不同族组分的脱附特性复配高效脱附剂的方法可行,复配脱附剂NP-8 5 & AEO-8 5对含油污泥的脱附效率可达89.40%.     

近距离煤层群倾向穿层钻孔合理布孔参数研究

为了解决新源煤矿在近距离煤层群赋存条件下采用倾向穿层钻孔抽采邻近煤(岩)层卸压瓦斯,抽采瓦斯浓度低,抽采率不达标,回采工作面上隅角瓦斯超限严重等问题。通过采用UDEC软件模拟采动覆岩移动破坏规律,获得开采2号煤层时上覆岩层裂隙带范围9~16m,确定倾向穿层钻孔合理布孔参数,钻孔倾角:21°~26°,孔深:44~47m。经在2219工作面试验考察,与原始参数钻孔抽采效果相比,钻孔平均瓦斯抽采浓度增加6倍多,抽采纯量增加15倍多,有效抽采距离增加3倍多,倾向穿层钻孔抽采率从20%提高到56.8%,回采期间上隅角瓦斯浓度能够控制在0.5%以下,保障了矿井安全生产。     

Untapped potential of collective intelligence in conservation and environmental decision making

Environmental decisions are often deferred to groups of experts, committees, or panels to develop climate policy, plan protected areas, or negotiate trade-offs for biodiversity conservation. There is, however, surprisingly little empirical research on the performance of group decision making related to the environment. We examined examples from a range of different disciplines, demonstrating the emergence of collective intelligence (CI) in the elicitation of quantitative estimates, crowdsourcing applications, and small-group problem solving. We explored the extent to which similar tools are used in environmental decision making. This revealed important gaps (e.g., a lack of integration of fundamental research in decision-making practice, absence of systematic evaluation frameworks) that obstruct mainstreaming of CI. By making judicious use of interdisciplinary learning opportunities, CI can be harnessed effectively to improve decision making in conservation and environmental management. To elicit reliable quantitative estimates an understanding of cognitive psychology and to optimize crowdsourcing artificial intelligence tools may need to be incorporated. The business literature offers insights into the importance of soft skills and diversity in team effectiveness. Environmental problems set a challenging and rich testing ground for collective-intelligence tools and frameworks. We argue this creates an opportunity for significant advancement in decision-making research and practice.     

我国群发性尘肺病和职业中毒案例分析及对策探讨

为有效预防和控制我国群发性职业损害，并为相关政策制定提供参考，对国内近30年文献记载的77个典型职业健康损害案例进行了统计分析，统计结果表明:群发性尘肺病主要集中于金属矿山、煤矿行业中小微型用人单位；群发性职业中毒多发生在电池制造、化工、鞋和箱包制造等用人单位。在典型案例原因分析的基础上，对有效落实用人单位职业病防治主体责任、完善工伤保险制度、建立健全相关制度等方面提出建议。     

Suppression of different functional group modified powders on 9.5% CH4-air explosion and molecular simulation mechanism

Thiol and urea functionalized montmorillonite powders were successfully prepared by silane coupling agent treatments in this work. The pyrolysis characteristics, surface functional groups, and distribution of particle size of untreated montmorillonite powders (Mt), the hydroxyl functionalized montmorillonite (O–Mt), the urea functionalized montmorillonite (N–Mt), and the thiol functionalized montmorillonite (S–Mt), which was derived from the previous research, were respectively characterized by utilizing the thermogravimetric differential scanning calorimetry, Fourier transform infrared spectroscopy, as well as the laser particle analyzer. The suppression effect of the S–Mt, O–Mt, Mt, and N–Mt on a 9.5% CH₄ explosion was tested in the duct system (5 L). The obtained results indicated that N–Mt and O–Mt exhibited a better explosion suppression effect than Mt and S–Mt at the same mass concentration. Additionally, the methane/air explosion suppression mechanism of these powders could be explained by molecular simulation results that indicated the negatively electrophilic potential regions exist on the surface of O–Mt and N–Mt. Moreover, NH₄∙、 NCO∙ and ∙OH radicals, which can interrupt explosive chain reactions, were easily generated by N–Mt and O–Mt.     

石楠不同季节除菌功能的调查与测定

通过对石楠不同季节单株和组群对环境除菌功能的调查与测定表明,春季除菌功能优于冬季,组群的除菌功能优于单株,同一植株离植株距离近的除菌功能效果明显.与对照相比,单株及组群的除菌功能优于裸地.