Derivation of predicted no effect concentrations (PNEC) for 2,4,6-trichlorophenol based on Chinese resident species

2,4,6-Trichlorophenol (2,4,6-TCP) is a common chemical intermediate and a by-product of water chlorination and combustion processes, and is a priority pollutant of the aquatic environment in many countries. Although information on the toxicity of 2,4,6-TCP is available, there is a lack of information on the predicted no-effect concentration (PNEC) of 2,4,6-TCP, mainly due to the shortage of chronic and site-specific toxicity data. In the present study, acute and sub-chronic toxicity of 2,4,6-TCP on six different resident Chinese aquatic species were determined. PNEC values were calculated and compared by use of two approaches: assessment factor (AF) and species sensitivity distribution (SSD). Values for acute toxicity ranged from 1.1 mg L⁻¹ (Plagiognathops microlepis) to 42 mg L⁻¹ (Corbicula fluminea) and the sub-chronic no observed effect concentrations (NOECs) ranged from 0.05 mg L⁻¹ (Mylopharyngodon piceus) to 2.0 mg L⁻¹ (C. fluminea). PNECs obtained by the assessment factor approach with acute (AF = 1000, 0.001 mg L⁻¹) or chronic (AF = 10, 0.005 mg L⁻¹) toxicity data were one order of magnitude less than those from SSD methods (0.057 mg L⁻¹). PNEC values calculated using SSD methods with a 50% certainty for 2,4,6-TCP was less than those obtained by use of the USEPA recommend final chronic value (FCV) method (0.097 mg L⁻¹) and the one obtained by use of the USEPA recommend acute-to-chronic (ACR) methods (0.073 mg L⁻¹). PNECs derived using AF methods were more protective and conservative than that derived using SSD methods.     

包头市区居民慢性疾病患病危险因子研究

筛查包头市区居民慢性疾病患病危险因子.     

Biological exposure models for oil spill impact analysis

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Analysis of the effects of zinc pollution on the macro-invertebrate populations of the Afon Crafnant,North Wales

The study of the input draining from mine-waste into the Afon Crafnant, N. Wales, revealed that the most significant pollutant was zinc. The concentrations of zinc were monitored during 1978 and 1979, and spot samples were concentrated and analysed for lead, copper, cadmium, iron, cobalt, manganese and nickel. Analysis was by flame atomic absorption specto-scopy. The total zinc concentration of the input was about 4 mg Zn/l which was diluted by the Afon Crafnant to give mean annual concentrations of 213 g Zn/l and 146 g Zn/l for 1978 and 1979 respectively at a site 60 metres downstream of the input. The numbers of individuals and number of taxa in the macro-invertebrate community were reduced at these concentrations. The taxa affected werePhagocata vitta,Erpobdella octoculata, Oligochaeta,Ithytrichia lamellaris, Simuliidae,Ancylus fluviatilis andRithrogena semicolorata. Several commonly used diversity indices failed to show differences between the macro- invertebrate communities at the affected and control sites whereas a modified version of Chandler's Biotic Score (detailed in this paper) revealed both the acute effects at higher concentrations and the chronic effects at lower concentrations.     

中西医结合治疗慢性胃窦炎50例临床观察

将50例慢性胃窦炎患者随机分为两组，治疗50例在对照组的基础上同时服用中药以疏肝理气和胃降逆为主。对照组的50例口服，果胶铋，羟氨苄胶囊，替硝唑治疗，两组以15d为1疗程，共治疗2个疗程．治疗组治愈32例，总有效率94．8％；对照组治愈25例，总有效率为77．8％，治率组的总有效率明显优于对照组（P〈0．05）．结果表明：中西医结合治疗慢性胃窦炎具有较好的临床疗效．     

Carbofuran toxicity on total lipids and free fatty acids in air breathing fish during exposure and cessation of exposure--in vivo

Clarias batrachus, fish were exposed to sublethalconcentration of commercial carbofuran for 144 hr. After 144 hrof exposure period, fish were transferred to fresh water and kept inthe same for 144 hr in order to study the effect of carbofuranafter cessation of intoxication. Total lipids and free fattyacids were determined in liver, muscle kidney and ovary at aninterval of 24, 72 and 144 hr during exposure and after therelease into toxicant free water. Total lipids increased in allthe tissues throughout the exposure period, followed by decreaseduring depuration period. The results showed an alteration infree fatty acid content in different tissues of the fish. Theelevated levels returned to almost control values after transferof fish into carbofuran free water.     

慢性氨氮胁迫对黄颡鱼摄食、生长及血液指标的影响

挑选规格相近的健康黄颡鱼幼鱼分别饲养在氨氮浓度为3.36 mg L-1(A1)、6.72 mg L-1(A2)、13.44 mg L-1(A3)、26.88 mg L-1(A4)的水体中,对照组(A0)用不加外源氨氮的自然晾晒的自来水饲养.每组放养试验鱼30尾,暴露56d.结果表明,非离子氨对黄颡鱼幼鱼的摄食、生长及血液指标存在显著影响(P<0.05),而对鱼体成分的影响不显著(P>0.05).随着非离子氨浓度升高,高浓度组摄食率明显下降,饲料利用率降低,生长缓慢,特定生长率(Specialgrowth rate,SGR)和存活率都较对照组低.血氨浓度随非离子氨浓度升高而显著升高(P<0.01),各处理组血氨浓度远低于其所处环境总氨氮(Total ammonia,TAN)浓度,而血浆尿素氮(Urea nitrogen,Ur-N)水平逐渐降低但差异不显著.A3和A4碱性磷酸酶(k p p,AKP)活性和皮质醇(Cortisol)水平升高较快,A1和A2尽管呈上升趋势,但与对照组差异不显著(P>0.05).血糖(Glucose,GLU)浓度总体上表现为降低的趋势,2个高浓度组(A3和A4)下降速度较快.谷丙转氨酶(Alamine aminotransferase,ALT)和谷草转氨酶(Aspartate aminotransferase,AST)活性总体呈升高趋势,非离子氨浓度越大其升高趋势越明显.因此,黄颡鱼幼鱼不宜长期生活在高浓度的氨氮胁迫环境中,适宜的养殖水体中氨氮应该保持在低于6.72 mg L-1水平.     

臭氧和PM2.5对慢阻肺死亡影响及气温修饰效应

采用广义相加模型评估臭氧和细颗粒物（PM_2.5）暴露对2008~2017年上海浦东居民慢性阻塞性肺疾病（COPD）死亡的超额危险度（ER）和寿命损失年（YLL）的影响.结果表明：臭氧污染集中在4~6月,PM_2.5污染集中在12月、1~2月,10a间臭氧浓度逐年增加,PM_2.5有小幅下降;在最大滞后效应下,臭氧每增加10μg/m³,ER和YLL分别为1.34%（95% CI：0.57%~2.12%）和54.98（95% CI：16.36~106.41）人·a;PM_2.5每增加10μg/m³,两者分别为2.66%（95% CI：1.54%~3.79%）和130.92（95% CI：42.47~274.28）人·a;臭氧对男性和<85岁人群影响显著,PM_2.5对女性和³85岁人群影响显著;暖季时臭氧暴露相关的COPD死亡风险更高,冷季时PM_2.5暴露相关的COPD死亡风险更高.臭氧和PM_2.5致COPD死亡的影响可能因气温水平而异.     

可吸入颗粒物在不同阻塞性呼吸道内运动与沉积特性

为弄清颗粒污染物在慢性阻塞性肺病工人呼吸道内运动和沉积规律,采用数值方法讨论了2类阻塞性呼吸道内气固流动特性,分析了阻塞率（α）、阻塞位置、劳动强度等因数对流场分布、颗粒沉积形式和沉积率的影响.结果表明,α越大,病人局部缺氧越严重,当α=0.8时,相对缺氧率可达90%以上;劳动强度越强或受阻塞位置越深,病人发生哮喘的可能性愈高.呼吸道变形不会改变颗粒的沉积机制,但对其沉积形式有显著影响.α增大,劳动强度增强,粒径变大,均会导致颗粒沉积分布不对称性提高,且下呼吸道粒子沉积分布对称性更好.此外,呼吸道变形使总沉降率（η_t）减小,且α越大,η_t越小.发现对于低劳动强度,下呼吸道或者d_p>5μm的大颗粒,α对η_t影响要更为显著.     

Acute/chronic ratios to estimate chronic toxicity from acute data

Acute toxicity of 25 narcotic compounds to D. magna was determined in this paper. Acute/ Chronic Ratios (ACRs), which are often used to estimate chronic toxicity from acute toxicity data, are discussed based on Quantitative Structure‐Activity Relationships (QSARs) of the compounds between both acute and chronic toxicity data and n‐octanol/water partition coefficients, and an improved equation is derived to estimate chronic toxicity data from acute toxicity data. Application of the improved equation and ACRs is illustrated for D. magna and fathead minnow to estimate chronic toxicity from acute toxicity.