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161.
Natural muds used as or in cosmetics may expose consumers to toxic metals and elements via absorption through the skin, inhalation of the dried product, or ingestion (by children). Despite the extensive therapeutic and cosmetic use of the Dead Sea muds, there apparently has been no assessment of the levels of such toxic elements as Pb, As, or Cd in the mud and mud-based products. Inductively coupled plasma mass spectrometry analysis of eight toxic elements in samples collected from three black mud deposits (Lisan Marl, Pleistocene age) on the eastern shore of the Dead Sea in Jordan revealed no special enrichment of toxic elements in the mud. A similar analysis of 16 different commercial Dead Sea mud cosmetics, including packaged mud, likewise revealed no toxic elements at elevated levels of concern. From a toxic element standpoint, the Dead Sea black muds and derivative products appear to be safe for the consumer. Whatever the therapeutic benefits of the mud, our comparison of the elemental fingerprints of the consumer products with those of the field samples revealed one disturbing aspect: Dead Sea black mud should not be a significant component of such items as hand creams, body lotions, shampoo, and moisturizer.  相似文献   
162.
Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene (PS) bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as "purge and trap" and analysed by gas chromatograph-mass spectrometer (GC/MS). Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 μg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 μg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.  相似文献   
163.
Environment, Development and Sustainability - The rapid population growth has rendered the centralized sewerage systems a non-realistic option in sparsely populated areas, particularly in...  相似文献   
164.
Environment, Development and Sustainability - In this work, a new model is developed to determine optimum sustainable economic order quantity (EOQ) and economic production quantity (EPQ) values for...  相似文献   
165.
Environment, Development and Sustainability - The prior empirical research focuses on examining only the procyclical impact of innovation on carbon emissions (CO2e), in the majority of cases, for...  相似文献   
166.
IntroductionWatercontaminantsincludealargenumberofchemicalsrangingfromaromatichydrocarbons,organicsolvents,pesticidesandmetals.Heavymetalcontaminationiscommonlyfoundinareaswhereindustrialeffluentsaredischargedintonaturalwaters .Theharmfuleffectsofsuchm…  相似文献   
167.
为验证气提式三重循环生物膜反应器处理甾体雌激素的效能,建立了一套SPE/HPLC/MS/MS分析方法,对反应器进、出水中的甾体雌激素--甾酮(E1),17β-雌二醇(E2),雌三醇(E3)以及17α-乙炔基雌二醇(EE2)进行检测.该方法的加标回收率为88%~103%,精密度为4%~9%.该方法对E1,E2,E3和EE2的进水定量限(LOQ)分别为0.7,0.8,0.9和0.5 ng/L;对出水的定量限分别为2.0,1.0,2.0和 1.0 ng/L.CODCr和氨氮容积负荷最高为7.5和1.6 kg/(m3·d),出水依然能够保持稳定.进水pH稳定在9.0~10.5,而反应器的pH一直稳定在9.0以下,体系对pH变化造成的冲击比较适应.同时,反应器内形成了稳定的NO2--N积累,CODCr和氨氮的去除率分别达到了70%和73%.  相似文献   
168.
Brachiomonas submarina Bohlin (Chlorophyceae), a euryhaline marine flagellate, can osmoregulate over a wide range of external salinity. The alga exhibits maximum water content at 100% artificial seawater (ASW), and shows only a small water loss (<15%) when salinity is increased to 300% ASW. The non-aqueous volume of the cells is increased at salinities higher than 100% ASW. This is partially attributable to the accumulation of glycerol. Glycerol is the major osmoregulatory organic solute in this flagellate. The alga also shows an accumulation of amino acids in response to increased salinity. The contribution of glycerol and amino acids to intracellular osmolarity is only 9% at 10% ASW, but accounts for 49% at 300% ASW. The remainder of the osmotic balance is due to uptake and accumulation of inorganic ions, particularly sodium, potassium and chloride.  相似文献   
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170.
The present studies on the age-specific life table of red cotton stainer suggest that the eggs and the initial immature stages are the most suceptible ones and a control measure if inflicted upon these, it might fetch the maximum result with the minimum usage of hazardous poisonous chemicals.  相似文献   
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