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1.
Copper mining activities are very important in central Chile.Like other metals, copper is a nutrient for most plants at lowconcentration levels; however, at higher levels it may becometoxic. At present, copper abundance in mediterraneanecosystems is unknown both for vegetation and soils. In thisstudy, two localities of the Coastal Range in central Chilewere studied. Copper content was found to be mainly related tosite type, and secondly to the components of the ecosystem.Copper contents are similar to other mediterranean ecosystemsof the world. Soil was found to represent the main source ofdata variation.  相似文献   

2.
通过对硼在我国34个省(自治区)、市的40种主要土类中的含量研究,提出硼在土壤环境中的分布规律,并对影响其分布特征的因素进行了探讨.  相似文献   

3.
以少量HNO_3-HF-HClO_4消解粉尘滤膜,石墨炉原子吸收法测定铅和锰,进行了最佳条件选择,采用本法测定粉尘中的铅和锰,其回收率分别为87%~98%和94%~105%,用标准加入法检验结果吻合,方法变异系数分别为铅4.1%,锰3.7%。  相似文献   

4.
论述了近年来国内在稀释测定生化需氧量(BOD5)中有关稀释倍数的研究成果;分析评价了一些确定稀释倍数的数理公式;总结了稀释法测定BOD5的基本要求。  相似文献   

5.
调查研究了塔里木河干流流域地下水中氟的含量水平及分布特征.揭示了地下水中氟与水化学性质之间的相互关系。探讨其形成高氟地下水的环境因素,并提出改水防病措施.  相似文献   

6.
用放射化学分析方法对哈密地区109份建材中天然放射性核素镭-226、钍-232、钾-40含量进行分析测定.结果表明,内、外照射指数分别为0.04-0.38和0.08-0.67,炉渣和花岗岩石最高,大理石和石灰、石膏最低.混合建材中镭-226、钍-232、钾-40含量(Bq/ kg)分别为 43.8, 40.0,594.0.建材所致居民内、外照射年有效剂量当量为 0.70mSv/ a,是我国《放射卫生防护基本标准》中规定公众个人年剂量当量限值5mSv的14.0%,不会对广大居民的健康造成有害的影响.  相似文献   

7.
系统地评述了饮用水中放射性核素的来源、水平、致人体剂量和对人体健康的影响,参考文献12篇。  相似文献   

8.
本文介绍了土壤背景值制图及其与其他地球化学图的异同;并在论述了国内外土壤背景值制图的方法及发展状况的基础上,指出制图的技术关键在于制图单元的选取和数值的分级.制图单元可根据资料的完整性及地质环境特征宜地选取,而数值的分级,尽管现有的方法各有所长,但要使所制的图在确实能够反映土壤地域差别的同时具有较强的可比性,就应力求建立统一的原则.  相似文献   

9.
石莹 《干旱环境监测》1994,8(3):160-162
探讨了一种简便的医院污水BOD测定中样品稀释倍数的推算方法。首先测定CODCr值,由CODCr值除以系数8,即获得稀释倍数C=CODCr/8。结果表明,该法仅需配制一个稀释比,省时省力,并具有可靠性好,准确度高,适应性强等优点。适用于各种医院污水中BOD的分析监测。  相似文献   

10.
Geographic Information Systems (GIS) and statistical methodswere used to identify the major factors affecting pesticideleaching in groundwater from agricultural fields in TulareCounty, California. Residues of bromacil, diuron, and simazineincreased in groundwater during the 1980s. Bromacil, diuron,and simazine contamination were positively correlated to cropdiversity and water demand. Diuron and simazine were positively correlated to groundwater depth and negatively correlatedto soil water-holding capacity. DBCP concentration in groundwater was related to the crop coverage. The Goss model wasused to examine soil-pesticide interactions and a PesticideContamination Index (PCI) was developed. Areas having highleaching potentials were mainly associated with citrus andorchards and coarse-textured sandy soils along the SierraNevada foothills, while areas having low leaching potentialswere associated with field crops and clay soils of the southwest region. The PCI was largest for DBCP during the 1980s,suggesting that it was the most significant contaminant before1977 when it was widely used; however, wells were not testedfor this pesticide during that period. Twelve years after DBCPwas banned, it was still the most significant health riskcontaminant. Spatial maps showing the distribution of leachingpotentials and soil interactions for these pesticides canprovide useful information to regulatory and planning agenciesfor land use planning and pesticide management.  相似文献   

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