Conceptual issues in designing a policy to phase out metal-based antifouling paints on recreational boats in San Diego Bay

In marine areas throughout the world where recreational boats are densely located, concentrations of copper in the water are being found to be in excess of government standards, due to the hull coatings used on these boats. Copper-based hull coatings are intended to be antifouling in that they retard the growth of algae, barnacles and tubeworms; but alternatives exist that can eliminate the harm that copper contamination does to marine organisms. A variety of policy options are available to mandate or provide economic incentives to switch to these less harmful alternatives. This paper puts forth a conceptual framework for thinking about how to design and evaluate alternative policies to transition to nontoxic boat hulls, drawing from the authors' experience designing a policy for use in San Diego Bay. Many of the issues raised are broadly applicable to environmental problems where the solution involves a large-scale replacement of durable consumer goods.     

Effects of 2,4-dichlorophenoxyacetic acid formulation on medulla spinalis of Poecilia reticulata: A histopathological study

This study investigated the possible effects of a commonly used foliar herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) formulation on medulla spinalis of lebistes. Fish were exposed to 2,4-D (15, 30, 45 mg L⁻¹), behavioral changes were monitored. Fish were fixed, histopathological examination was carried out on sections taken from the upper parts of the fish body. Histopathology showed increase in neuronal loss, swelling indicating formation of intracellular edema, vacuolization noticed as the formation of vacuoles within or adjacent to cells, deformation in the Nissl granules, pyknosis and gliosis in medulla spinalis. Behavioral changes were decreased general activity, grouping, shortness in breath, sudden rotations and jumping, loss of equilibrium and colour. In conclusion, this commercial formulation of 2,4-D is considerably neurotoxic to lebistes. Fish constitute the last link in the chain of the feeding cycle in aquatic eco-system, number of studies investigating acute and chronic neurotoxicity of various herbicides in fish should be increased.     

氧化亚铁硫杆菌浸出废弃线路板中铜的研究

对废弃线路板中的铜进行了细菌浸出、只有硫酸亚铁环境下的浸出及酸浸出实验,研究了不同条件对比浸出效果,研究结果表明,细菌浸出比只有硫酸亚铁存在的浸出和酸浸要快得多。研究了在线路板粉末浓度12、24、40、60和120 g/L下浸出速率的变化,结果表明, 在考察范围内,浸出速度随着加入的废弃线路板粉末浓度的升高而降低,当线路板粉末的浓度＞60 g/L时,浸出速度维持在较低水平,选取24 g/L作为浸出的线路板粉末的浓度。分别在细菌培养0、24、48和72 h时加入线路板粉末24 g/L进行浸出实验,结果表明,细菌培养时间长,使得浸出过程进行得也更快。     

Seven thousand years in the service of humanity—the history of copper, the red metal

Measured by weight, copper is the third most important metal used by man. The annual value of its 2007 output was on a par with the GDP of e.g. Ukraine. Copper is also one of the oldest metals, its employment going back 7000 years. For millennia, it was predominantly employed for decorative purposes, coinage and in warfare. Technical breakthroughs in antiquity, like smelting and alloying, expanded its production and enhanced its utility. Copper's true heyday occurred after 1850, with the usage of electricity. In the period since then, volumes increased 300-fold, while costs and prices declined. With impressive progress in the technology of its production and consumption, the red metal has been able to hold its own, despite the emergence over history of formidable substitutes like iron, aluminum, plastics and optic fiber.     

油田固体废物的毒性试验研究

通过对某油田3个区域井场的废弃钻井液和取自集输站及注水站的油泥(砂)等两种固体废物进行急性生物毒性试验和浸出毒性试验,试验结果表明:该油田的废弃钻井液急性生物毒性相对较大,油泥(砂)不具有急性生物毒性;这两种固体废物均不具有浸出毒性和腐蚀性。     

新亚铜灵--直接全差示光度法测定水中微量铜

实验了新亚铜灵--直接全差示光度法测定水中微量铜.与新亚铜灵萃取光度法相比较,该方法具有操作简单、灵敏度较高、不使用氯仿等优点.方法回收率为96%～103%,相对标准偏差为0.26%～3.6%,最低检出限为0.002mg/L.     

用Ames试验检测水源水和自来水中的遗传毒性

用微伤寒沙门氏菌／哺乳动物微粒体酶系的Ａｍａｅｓ试验,研究了不同季节物水源水及管网自来水中的遗传毒性,以ＸＡＤ２树脂为吸附剂,以丙酮－甲醇的混合液为洗脱液,浓率水样中的有机物,并对部分阳性水样进行有机成分的定性分析。结果发现：１３个水样中有７个样品在淡需要代谢活化系统Ｓ９的情况下,可诱导鼠伤寒沙门氏菌碱基移码型菌株的回复突变;不同水样在不同季节不同的诱导作用;同时通过ＧＣ／ＭＳ方法分析,发现阳性水     

Heavy metal contamination from mining sites in South Morocco: Monitoring metal content and toxicity of soil runoff and groundwater

The aim of the present work is the assessment of metal toxicity in runoff, in their contaminated soils and in the groundwater sampled from two mining areas in the region of Marrakech using a microbial bioassay MetPLATE™. This bioassay is based on the specific inhibition of the β-galactosidase enzyme of a mutant strain of Escherichia coli, by the metallic pollutants. The stream waters from all sampling stations in the two mines were all very toxic and displayed percent enzyme inhibition exceeding 87% except SWA₄ and SWB₁ stations in mine C. Their high concentrations of copper (Cu) and zinc (Zn) confirm the acute toxicity shown by MetPLATE. The pH of stream waters from mine B and C varied between 2.1 and 6.2 and was probably responsible for metal mobilization, suggesting a problem of acid mine drainage in these mining areas. The bioassay MetPLATE™ was also applied to mine tailings and to soils contaminated by the acidic waters. The results show that the high toxicity of these soils and tailings was mainly due to the relatively concentration of soluble Zn and Cu. The use of MetPLATE™ in groundwater toxicity testing shows that, most of the samples exhibited low metal toxicity (2.7–45.5% inhibition) except GW3 of the mine B (95.3% inhibition during the wet season and 82.9% inhibition during the dry season). This high toxicity is attributed to the higher than usual concentrations of Cu (189 μg Cu l⁻¹) and Zn (1505 μg Zn l⁻¹). These results show the potential risk of the contamination of different ecosystems situated to the vicinity of these two metalliferous sites. The general trend observed was an increase in metal toxicity measured by the MetPLATE with increasing total and mobile metal concentrations in the studied matrices. Therefore, the MetPLATE bioassay is a reliable and fast bioassay to estimate the metals toxicity in the aquatic and solids samples.     

Growth, photosynthetic and respiratory responses to sub-lethal copper concentrations in Scenedesmus incrassatulus (Chlorophyceae)

In the present paper we investigated the effects of sub-lethal concentrations of Cu²⁺ in the growth and metabolism of Scenedesmus incrassatulus. We found that the effect of Cu²⁺ on growth, photosynthetic pigments (chlorophylls and carotenoids) and metabolism do not follow the same pattern. Photosynthesis was more sensitive than respiration. The analysis of chlorophyll a fluorescence transient shows that the effect of sub-lethal Cu²⁺ concentration in vivo, causes a reduction of the active PSII reaction centers and the primary charge separation, decreasing the quantum yield of PSII, the electron transport rate and the photosynthetic O₂ evolution. The order of sensitivity found was: Growth > photosynthetic pigments content = photosynthetic O₂ evolution > photosynthetic electron transport > respiration. The uncoupled relationship between growth and metabolism is discussed.