A Comparative Study of the Effects of Metal Contamination on Collembola in the Field and in the Laboratory

We examined the species diversity and abundance of Collembola at 32 sampling points along a gradient of metal contamination in a rough grassland site (Wolverhampton, England), formerly used for the disposal of metal-rich smelting waste. Differences in the concentrations of Cd, Cu, Pb and Zn between the least and most contaminated part of the 35 metre transect were more than one order of magnitude. A gradient of Zn concentrations from 597 to 9080 microg g(-1) dry soil was found. A comparison between field concentrations of the four metals and previous studies on their relative toxicities to Collembola, suggested that Zn is likely to be responsible for any ecotoxicological effects on springtails at this site. Euedaphic (soil dwelling) Collembola were extracted by placing soil cores into Tullgren funnels and epedaphic (surface dwelling) species were sampled using pitfall traps. There was no obvious relationship between the total abundance, or a range of commonly used diversity indices, and Zn levels in soils. However, individual species showed considerable differences in abundance. Metal "tolerant" (e.g., Ceratophysella denticulata) and metal "sensitive" (e.g., Cryptopygus thermophilus) species could be identified. Epedaphic species appeared to be influenced less by metal contamination than euedaphic species. This difference is probably due to the higher mobility and lower contact with the soil pore water of epedaphic springtails in comparison to euedaphic Collembola. In an experiment exposing the standard test springtail, Folsomia candida, to soils from all 32 sampling points, adult survival and reproduction showed small but significant negative relationships with total Zn concentrations. Nevertheless, juveniles were still produced from eggs laid by females in the most contaminated soils with 9080 microg g(-1) Zn. Folsomia candida is much more sensitive to equivalent concentrations of Zn in the standard OECD soil. Thus, care should be taken in extrapolating the results of laboratory toxicity tests on metals in OECD soil to field soils, in which, the biological availability of contaminants is likely to be lower. Our studies have shown the importance of ecotoxicological effects at the species level. Although there may be no differences in overall abundance, sensitive species that are numerous in contaminated sites, and which may play important roles in decomposition ("keystone species") can be greatly reduced in numbers by pollution.     

Influences of Quinclorac on Culturable Microorganisms and Soil Respiration in Flooded Paddy Soil

Objective To investigate the potential effects of herbicide quinclorac (3,7-dichloro-8-quinolinecarboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes and fungi were counted by a 10-fold serial dilution plate technique. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid ertrichment media. The number of methanogenic bacteria (MB) and nitrogen-fixing bacteria (NFB) was determined by the rolling tube method in triplicate. Soil respiration was monitored by a 102G-type gas chromatography with a stainless steel column filled with GDX-104 and a thermal conductivity detector. Results Quinclorac concentration was an important factor affecting the populations of various culturable microorganisms. There were some significant differences in the aerobic heterotrophic bacteria. AFB an     

Effect of zinc and benzalkonium chloride on Nitrosomonas communis and potential nitrification in soil

A bacterial contact assay is described which uses a chemoautotrophic microorganism, Nitrosomonas communis (strain Nm2) to evaluate the biological effect of contaminated soils. The effects of two toxicants on the ammonium oxidation activity of the autochthonous microbial population in the soil are compared with inhibition of the same biological response in the new monospecies bioassay. Experiments were performed using soil samples dosed with organic and inorganic contaminants (benzalkonium chloride and zinc) to demonstrate the mode of operation and the sensitivity of the bioassay. The EC50 values of zinc and benzalkonium chloride were calculated to be 171 and 221 mg kg-1 soil, respectively. The toxic response provided by the bioassay can thus predict the effect of soil pollutants on the autochthonous nitrifying bacteria.     

Control of chemical risks during the treatment of soil contaminated with chlorophenol, creosote and copper-chrome-arsenic-wood preservatives

BACKGROUND: Exposure to chemicals in polluted soil was studied during the remediation of four polluted sites. They are sawmill areas contaminated with chlorophenols and polychlorinated dibenzo-p-dioxins and furanes (PCDD/F), wood impregnating plants contaminated with polycyclic aromatic hydrocarbons (PAH) from creosote oil, old gas works area contaminated with PAH, and a wood impregnation plant contaminated with copper-chromium-arsenic (CCA) preservative. METHODS: The exposure levels were determined by both air and biological monitoring. RESULTS: Air monitoring showed that the exposure levels were generally well below the current occupational exposure limits. The calculations indicated, however, that the lowest acceptable daily intake value recommended for PCDD/F by the U.S. Environmental Protection Agency was exceeded. Chlorophenol exposure was generally low. Exposure to volatile PAH was 0.038-0.884 mg/m(3) and that to particulate PAH was 0.004-0.183 mg/m(3). The biomonitoring results (urinary 1-pyrenol) suggested that some exposure occurs, probably through the contamination of hands or skin absorption. At the sites contaminated with CCA salts, no exposure limits were exceeded. CONCLUSIONS: The results generally suggest that the exposure of cleanup workers is generally below the current occupational exposure limits but that short-term high exposure cannot be excluded. There was also some indication of poor skin protection, which should be improved when soil contaminated with PAH and creosote oil is handled.     

3种白蚁药剂的渗透深度及土壤化学屏障的评价研究

目的为了确定白蚁防治中土壤化学屏障的取样深度及含药量。方法通过对联苯菊酯(0.062 5%)、毒死蜱(1%)、吡虫啉(0.1%)3种白蚁药剂在室内、野外条件下的浸透深度研究及白蚁预防施工现场的实验数据检测分析。结果在室内土柱的渗透试验中,在4 L/m2的施药量下施用24 h后,3种药剂98%以上的含量都在表层0~5 cm层;在野外试验中,其90%以上的含量都在0~10 cm层。室内外10~15 cm的土层有少量药剂,药剂基本上没有渗透至15~20 cm的土层。施工现场的检测数据表明,不同地区的结果差异很大。结论按房屋白蚁预防施工操作规程,以4 L/m2药剂进行施工时,确定取样深度为10 cm,同时建议1%毒死蜱、0.062 5%联苯菊酯和0.1%吡虫啉的土壤屏障的含药量分别为290,18,29 mg/kg。     

中药黄藤GAP基地环境质量评价

目的黄藤种植基地生态环境质量进行评价。方法空气质量监测采用国家规定环境空气质量标准(GB3095-1966)及其分析方法进行分析,土壤环境检测按国家标准GB15618-1995(土壤环境质量标准)和YB-T-1-2003(药用植物绿色出口生产基地行业标准,增加五氯硝基苯、艾氏剂项目)的方法和要求进行。灌溉水质采用GB5084-92《农田灌溉水质标准》要求进行检测。结果黄藤种植基地大气质量达到GB3095-1996一级标准,水源质量达GB5084-92标准,土壤环境达GB15618-1995二级标准。结论广西上思县那琴乡黄藤种植基地环境质量良好,各生态条件适合黄藤生长,土壤含磷钾素较高,有利于黄藤的生长和有效成分的积累。符合药用植物绿色出口生产基地行业标准(YB-T-1-2003)的要求。     

氧氟沙星注射液不良反应的临床监测与治疗

随着氧氟沙星注射液（ｏｆｌｏｘａｃｉｎ）临床应用的不断扩大,由其导致的各种不良反应的发生和耐药菌株的产生呈逐年增长趋势,现将本院为期４年的氧氟沙星注射液的临床用药监测及治疗情况进行分析总结以供临床参考。１　临床资料与方法１．１　资料来源　调查材料来源于我院３０个病区的高年资医师、护士长、科主任、护士等监察员,对所发生的药物不良反应（ＡＤＲ）即作为本次调查统计资料,６７份氧氟沙星ＡＤＲ报告表来源如表１所列。１．２　监测方法　按卫生部药品不良反应监察中心ＡＤＲ报告表（１９９４年版）填表说明上的因果关…     

土壤样品中放射性核素γ谱分析比对

本文报道并讨论了15个实验室用γ谱仪对两个土壤样品和一个参考标准模拟土壤样品中放射性核素分析比对的结果。对样品的制备、均匀性测定以及比对程序也作了介绍。根据各实验室的数据对样品中的几个主要核素的测定值作了估计。大约有91%的实验室对三个样品的各种核素分析的相对标准偏差小于±20%。有88%的实验室平均值与参考值在±10%内相符合。统计分析表明,个别实验室对偶然误差估计可能不合理或存在系统误差。     

氮钾肥配施对赤红壤上甜玉米生长影响的研究

本文研究氮、钾肥配施对赤红壤上甜玉米生长的影响,于1986年秋作和1987年春作进行两次盆栽试验及植株和土壤的化学分析。结果表明:氮、钾肥配施可增加供试土壤有效氮和速效钾含量,可增加甜玉米穗叶(吐丝明)含N量和含K量,降低穗叶含P量、含Ca量和含mg量。不施钾肥处理的甜玉米穗叶含K量≤1.30％,吐丝前有明显的缺K症。施高量钾肥(0.33克KCl/公斤土)处理的穗叶含Mg量≤0.15％;吐丝后出现明显的缺Mg症;施K_1水平(0.17克KCl/公斤土)的钾肥较适宜。单施氮肥处理,甜玉米果穗和籽粒的产量随施氮量增加而显著降低。配施钾肥处理,甜玉米增产率随施氮量增加而增大。增施氮肥可明显增加籽粒粗蛋白质含量,降低水溶性糖含量。施钾肥与不施钾肥比可明显增加水溶性糖含量,增加粗蛋白质总量(克/盆),但降低租旦白质含量。在供试赤红壤盆栽甜玉米条件下,氮钾肥配施以N_2K_1处理为宜