Interaction between cadmium and lead and the effects of these on the concentration of zinc and manganese in sunflower

The pollution of soil by heavy metals is considered to be quite a big problem in many areas of the world. To limit the accumulation of lead and cadmium from soil in the products, a correct understanding of the characteristics and specifications of the translocation of cadmium and lead is necessary. In order to evaluate the effects of cadmium and lead interaction on zinc and manganese concentration, three levels of cadmium [0, 100 and 200 mg/kg], and three levels of lead [0, 200 and 400mg/kg] were tested on a sunflower cultivar SHF81- 85 in a factorial experimental design with three replications. The results showed that cadmium has increased the cadmium and lead concentration in the shoot and root, while the effects of lead, were only significant on the concentration of lead in the shoot, and the concentration of both cadmium and lead in the root [p<0.05]. Cadmium and lead revealed a preventing effect on zinc and manganese concentration in the root and shoot of the plant. More investigations at field conditions are recommended

Removal of lead from aqueous effluents by adsorption on coconut shell carbon.

The application of adsorption for removal of heavy metals is quite popular and activated carbon is universally used as an adsorbent. However, high cost of its preparation and regeneration has led to a search for alternative sorbents, especially in the developing countries. A number of sorbents are used to remove metals by adsorption from industrial effluents, which include insoluble starch, xanthates, modified cotton and wool, tree barks, activated carbon, plant leaves and agricultural products. Therefore, as an alternative, coconut shell carbon (CSC), a low cost sorbent derived from organic waste material, was used in the present work, for removal of lead from aqueous effluents. The results of the batch sorption studies indicated that the efficiency of lead removal by coconut shell carbon is comparable to that of commercially available activated carbon. From the kinetic and equilibrium studies, the sorptive capacity of coconut shell carbon for lead was found to be 30 mg/g. Desorption and subsequent recovery of the metal from the surface of the sorbent was successfully demonstrated. Parameters affecting the sorption were evaluated.

Chemical composition, metals content and pesticide residues in raw, pasteurized and UHT milk and their dietary intake

Chemical composition, metal contents and pesticide residues were determined in raw, pasteurized and UHT [Ultra High Temperature] milk samples collected from local markets in Cairo Governorate, Egypt. Fat, T.P. [Total Protein], ash, lactose and T.S. [Total Solids] contents were [3.50, 3.20, 0.71, 4.10 and 11.40%], [3.00, 3.50, 0.80, 4.65 and 11.50%], and [3.00, 3.40, 0.80, 4.44 and 11.50%] in raw, pasteurized and UHT milk, respectively. Levels of Zn, Fe, Cu, Mn, Cr, Ni, Co, Pb, Cd and Sn were [3.59, 0.62, 0.17, 0.06, 0.03, 0.036, 0.032, 0.032, 0.025 and 0.002 mg/kg], [3.11, 0.55, 0.15, 0.041, 0.030, 0.030, 0.030, 0.021, 0.022 and 0.002 mg/kg] and [3.11, 0.60, 0.180, 0.050, 0.020, 0.030, 0.030, 0.020, 0.020 and 0.002 mg/kg] in raw, pasteurized and UHT milk, respectively. Organochlorine pesticides [HCB, lindane, aldrin, heptachlor, heptachlor epoxide, chlordane, endrin and DDT metabolites] were detected in raw milk at levels higher than the tolerance limits. However, these chemicals were detected in pasteurized milk at slightly higher levels and in UHT milk at levels lower than the tolerance limits. On the other hand, non of raw, pasteurized and UHT milk revealed the presence of organophosphorus pesticides [malathion, profenofos, pirmiphos-methyl and dimethoate]. To assess any possible risks to consumers of milk, dietary intakes have been estimated using the mean concentration of various metals and pesticide residues in this monitoring. Data showed that, daily intake of the investigated metals and pesticides in milk were lower than the recommended levels except that Pb and Cd are higher than it

Remediation of lead from lead electroplating industrial effluent using sago waste.

Heavy metals are known toxicants, which inflict acute disorders to the living beings. Electroplating industries pose great threat to the environment through heavy load of metals in the wastewater discharged on land and water sources. In the present study, sago processing waste, which is both a waste and a pollutant, was used to adsorb lead ions from lead electroplating industrial effluent. Two types of sago wastes, namely, coarse sago waste and fine sago waste were used to study their adsorption capacity with the batch adsorption and Freundlich adsorption isotherm. The parameters that were considered for batch adsorption were pH (4, 5 and 6), time of contact (1, 2 and 3 hrs), temperature (30, 37 and 45 degrees C) and dosage of the adsorbent (2,4 and 6 g/L). The optimal condition for the effective removal of lead was found to be pH 5, time of contact 3 hrs, temperature 30 degrees C and dosage 4 g/L with coarse sago waste than fine sago waste.

Dynamics of lead (Pb) in different soil conditions.

Four soil samples were collected from various locations having wider range of pH and EC for incubation experiment. These soil samples were added with Pb (NO3)2 salts, and samples were taken on 1st, 35th, 45thand 60th day. Soils samples were fractioned by sequential extraction to estimate the concentration of lead in different fractions viz, water soluble, exchangeable +adsorbed, organic, carbonate and residual fraction. The result reveals that concentration of organic and carbonate bound-Pb was high in waterlogged condition and soil pH has been comprehensively identified as the single most important soil factor controlling the availability of lead (Pb) in soil. Low content of Pb in exchangeable + adsorbed (KNO3) and water soluble (H2O) fraction in all soils (except in S1) could signify low availability of Pb to plants. Bioavailable fractions, viz. water soluble and exchangeable + adsorbed, were low in all soils (except S1) well below critical limits, which may not pose any toxicity in the food chain.

EDTA-assisted phytoextraction of lead from lead-contaminated soils by Echinochloa crusgalli var. frumentacea.

The herbaceous plant Echinochloa crusgalli var. frumentacea is highly resistant to a wide range of heavy metal concentrations. In this study we tested the phytoextraction capacity of E. crusgalli var. frumentacea. Specifically, we compared the effect of EDTA on lead (Pb) accumulation in two groups of plants: those sown in lead contaminated soil and those transplanted to the contaminated soil as seedlings. The result of the time development of the Pb concentrations in the plants in the seedling and seed groups shows that for the seedling group, the effect of adding EDTA to the Pb-contaminated soil was even more pronounced in the shoots than the roots, which showed Pb concentrations 32-fold higher. Compared to the seedling group, the Pb concentrations in the roots of plants in the seed group were approximately 5 times higher in controls and 2 to 10 times higher in the presence of EDTA. Collectively, these results might be considered that EDTA elevates the bioavailability of Pb in soil and this native species is particularly suited to use in Pb phytoextraction.

impact of heavy metals on the energy reserves of lepidotriglae lastovisa from the South-Eastern Mediterranean, Alexandria, Egypt

Lepidotriglae lastovisa were collected monthly over one annual reproductive cycle, from January to December 1994. Total lipid, protein, Pb and Cd content were determined in muscles, liver and gonads of mature [>13 cm length] and immature [8-13 cm length] fishes of both sexes. Mercury content was determined in fish muscles of both sexes at different lengths during one month. Lipids were primarily transported to ovaries prior to fertilization. Energetic lipids were maximal in liver and muscles before spawning and declined to the minimum after spawning, during early winter. L lastovisa spawns two times a year, from February to April, and from August to October. Fish that spawned early still had plenty of fat left in muscles it probably takes its energy from liver fat, while late spawners had low fat reserves [declined by about 70%]. The total energy required for gonad development were significantly parallel in both sexes, and were mostly consumed from lipid mobilization rather than protein. The body lipid content increased significantly during the period of heavy phytoplankton blooms [July and September] and declined in winter. Muscle protein was found to be related to that in the ambient water. Mercury content showed similar distribution patterns in both sexes, being accumulated with growth. The general levels of Pb and Cd were remarkably high in different tissues, which may be traced to the elevated levels in surrounding water, sediments and biota. Bioaccumulation of such metals occurred in almost the same proportion as the total discharge to the area. Such elevations in metals seem to reduce the body energy reserve, where significant inverse correlations between total energy [in the form of lipid and protein] with Cd and Pb was computed and assessed

Chumbo: aspectos químicos e implicaçöes clínicas / Lead: chemical aspects and clinical implications

Os autores revisam os aspectos químicos do chumbo, bem como os efeitos oriundos da exposiçäo a este elemento, como intoxicaçäo pelo chumbo

Atividade moluscicida da mistura de ácidos 6-n-alquil salicílicos (ácido anacárdico) e dos seus complexos com cobre (II) e chumbo (II) / Molluscacide activity of a mixture of 6-n-alkyl salicylic acids (anardic acid) and 2 of its complexes with copper (II) and lead (II)

Foi comparada, em laboratório, a atividade moluscicida do extrato hexânico da casca da castanha do caju - Anacardium occidentale L. (EHCCC), do complexo de cobre (II), do complexo de chumbo (II) e do ácido anacárdico com objetivo de encontrar entre eles um produto que apresentasse maior estabilidade que o ácido anacárdico. Este foi preparado tratando o EHCCC com hidróxido de chumbo (II) ou com o sulfato de cobre mais hidróxido de sódio ou com hidróxido de cobre (II). Em seguida, o complexo de chumbo (II) ou os complexos de cobre(II) preprarados foram tratados com uma soluçäo de ácido sulfúrico diluída. As misturas dos dez produtos obtidos foram testadas sobre caramujos adultos de Biomphalaria galabrata nas concentraçöes de 1 a 10 ppm. Os mais ativos foram o compleso de cobre (II), obtido com sulfato de cobre mais hidróxido de sódio, e o ácido anacárdico (hidróxido de chumbo) que apresentaram atividade a partir da concentraçäo de 4ppm. O teor de chumbo do ácido anacárdico (hidróxido de chumbo) foi acima das normas recomendadas pelos Padröes de Saúde Pública dos Estados Unidos

Biochemical studies on human cervical mucous in infertility

We studied 25 infertile women in whomn in whom cervical hostility was the only known cause of infertility, and 10 fertile women. Total soluble proteins, IgG, IgA and IgM togeter with zinc, copper manganese and lead were measured in mid-menstrual cycle cervical mucus. IgG and IgA were present in the cervical mucus of all the women. But IgM was detected only in 20% of samples of fertile women and in 36% of samples of infertile women. Levels of IgA and total soluble proteins were significantly higher in the infertile group. Zinc, Copper and manganese were present in cervical mucus and the concentrations found did not differ significantly in the tow groups. Lead was not detected in all cervical mucus samples in the two groups