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Resultados 1781-1790 de 62,396
Explore the health-related limits of wastewater treatment and reuse.
1976
Gannon T.J.
Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n = 51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p < 0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n = 20) and brown bran (n = 31) (Wilcoxon rank sum, p = 0.06–0.91). Compared to all elements in rice, rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson's r = 0.33, p < 0.05) and total mercury (r = 0.44, p < 0.05), while strontium (i.e., tracer for xylem transport) was least correlated with total mercury and methylmercury (r < 0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem.
Mostrar más [+] Menos [-]Pollution of camel milk by heavy metals in Kazakhstan Texto completo
2009
Konuspayeva G. | Faye B. | Loiseau G. | Diacono E. | Akhmetsadykova S.
Environmental contamination by heavy metals is a common fact in Central Asia. In the present study two sampling procedures were achieved: (i) Sampling of fodder, camel raw milk and shubat (fermented camel milk) in 8 farms closed to pollution sources from the South of Kazakhstan for copper, iron, manganese, zinc, arsenic and lead analysis, (ii) sampling of camel milk in 4 regions of Kazakhstan (63 samples) analyzed for lead, chrome and zinc contamination. In first sampling, camel milk contained 0.07 ± 0.04, 1.48 ± 0.53, 0.08 ± 0.03, 5.16 ± 2.17, <0.1 and 0.025 ± 0.02 ppm respectively for Cu, Fe, Mn, Zn, As and Pb. In shubat (fermented milk) the mean content was 0.163 ± 0.164, 1.57 ± 0.46, 0.088 ± 0.02, 7.217 ± 2.55 and 0.007 ppm respectively. Arsenic was detected in some samples of milk and shubat only. The trace elements concentration increase in shubat compared to milk but lead concentration decreased. No clear correlation was observed with fodder composition. In second sampling, the lead content was on average 250 ± 56 ppb in the camel milk with no significant differences between regions. The maximum value was observed at Atyrau (532 ppb). Zinc content in milk (5.42 ± 0.2 ppm) did not change significantly between regions. In reverse, chrome (59.5 ± 45.4 ppb) was higher in Shymkent region compared to others. These values were discussed according to the proximity of pollution sources. Specially, higher concentrations were experienced in fodder from pastures close to some industrial sites or high traffic road. (Résumé d'auteur)
Mostrar más [+] Menos [-]Soil thresholds and a decision tool to manage food safety of crops grown in chlordecone polluted soil in the French West Indies Texto completo
2017
Clostre F. | Letourmy P. | Lesueur Jannoyer M.
Due to the persistent pollution of soils by an organochlorine, chlordecone (CLD also known as Kepone ©) in the French West Indies, some crops may be contaminated beyond the European regulatory threshold, the maximum residue limit (MRL). Farmers need to be able to foresee the risk of not complying with the regulatory threshold in each field and for each crop, if not, farmers whose fields are contaminated would have to stop cultivating certain crops in the fields concerned. To help farmers make the right choices, we studied the relationship between contamination of the soil and contamination of crops. We showed that contamination of a crop by CLD depended on the crop concerned, the soil CLD content and the type of soil. We grouped crop products in three categories: (i) non-uptakers and low-uptakers, (ii) medium-uptakers, and (iii) high-uptakers, according to their level of contamination and the resulting risk of exceeding MRL. Using a simulation model, we computed the soil threshold required to ensure the risk of not complying with MRL was sufficiently low for each crop product and soil type. Threshold values ranged from 0.02 ?gkg?1 for dasheen grown in nitisol to 1.7 ?gkg?1 for yam grown in andosol in the high-uptake category, and from 1 ?gkg?1 for lettuce grown in nitisol to 45 ?gkg?1 for the leaves of spring onions grown in andosol in the medium-uptake category. Contamination of non-uptakers and low-uptakers did not depend on soil contamination. With these results, we built an easy-to-use decision support tool based on two soil thresholds (0.1 and 1 ?gkg?1) to enable growers to adapt their cropping system and hence to be able to continue farming. (Résumé d'auteur)tttttt
Mostrar más [+] Menos [-]Persistence of detectable insecticidal proteins from #Bacillus thuringiensis# (Cry) and toxicity after adsorption on contrasting soils Texto completo
2016
Hung T.P. | Truong L.V. | Binh N.D. | Frutos R. | Quiquampoix H. | Staunton S.
Persistence of detectable insecticidal proteins from #Bacillus thuringiensis# (Cry) and toxicity after adsorption on contrasting soils Texto completo
2016
Hung T.P. | Truong L.V. | Binh N.D. | Frutos R. | Quiquampoix H. | Staunton S.
Insecticidal Cry, or Bt, proteins are produced by the soil-endemic bacterium, Bacillus thuringiensis and some genetically modified crops. Their environmental fate depends on interactions with soil. Little is known about the toxicity of adsorbed proteins and the change in toxicity over time. We incubated Cry1Ac and Cry2A in contrasting soils subjected to different treatments to inhibit microbial activity. The toxin was chemically extracted and immunoassayed. Manduca sexta was the target insect for biotests. Extractable toxin decreased during incubation for up to four weeks. Toxicity of Cry1Ac was maintained in the adsorbed state, but lost after 2 weeks incubation at 25 °C. The decline in extractable protein and toxicity were much slower at 4 °C with no significant effect of soil sterilization. The major driving force for decline may be time-dependent fixation of adsorbed protein, leading to a decrease in the extraction yield in vitro, paralleled by decreasing solubilisation in the larval gut. (Résumé d'auteur)
Mostrar más [+] Menos [-]Persistence of detectable insecticidal proteins from Bacillus thuringiensis (Cry) and toxicity after adsorption on contrasting soils Texto completo
2016
Hung, T.P. | Truong, L.V. | Binh, N.D. | Frutos, R. | Quiquampoix, H. | Staunton, S.
Insecticidal Cry, or Bt, proteins are produced by the soil-endemic bacterium, Bacillus thuringiensis and some genetically modified crops. Their environmental fate depends on interactions with soil. Little is known about the toxicity of adsorbed proteins and the change in toxicity over time. We incubated Cry1Ac and Cry2A in contrasting soils subjected to different treatments to inhibit microbial activity. The toxin was chemically extracted and immunoassayed. Manduca sexta was the target insect for biotests. Extractable toxin decreased during incubation for up to four weeks. Toxicity of Cry1Ac was maintained in the adsorbed state, but lost after 2 weeks incubation at 25 °C. The decline in extractable protein and toxicity were much slower at 4 °C with no significant effect of soil sterilization. The major driving force for decline may be time-dependent fixation of adsorbed protein, leading to a decrease in the extraction yield in vitro, paralleled by decreasing solubilisation in the larval gut.
Mostrar más [+] Menos [-]Investigating filamentous slime growth downstream of a municipal discharge [Sacramento River, California].
1978
Salo J.E. | Ikesaki T.
Copper smelters and atmospheric visibility in the southwest, seasonal analysis [Nevada; Utah; Texas; Colorado; Arizona; New Mexico].
1984
Nochumson D.H. | Williams M.D.
Validation of the industrial source complex dispersion model in a rural setting [Air pollution].
1984
Heron T.M. | Kelly J.F. | Haataja P.G.
Using farmers' actions to measure crop loss due to air pollution [Ozone, Illinois].
1984
Mjelde J.W. | Adams R.M. | Dixon B.L. | Garcia P.
A review of recent reports dealing with the greenhouse effect of atmospheric carbon dioxide.
1984
Idso S.B.
