Wyniki wyszukiwania - Biblioteka Nauki

1

Lead in Agricultural Soils and Cultivated Pastures Irrigated with River Water Contaminated by Mining Activity

100%

Orellana E. , Custodio M. , Bastos M. C. , Cuadrado W.

Journal of Ecological Engineering

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2019

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tom Vol. 20, nr 8

238--244

EN

Agricultural soils that have been irrigated with the contaminated water from metallurgical mining activities for more than 70 years constitute an environmental problem as well as a concern for food security and human health. The presence of lead in the soil and cultivated pastures is highly dangerous, due to its toxicity, persistence and accumulation in plants and animals (cattle). This element enters the trophic chain of humans due to the intake of meat, milk and its derivatives. The concentration of lead was determined in the soil and the cultivated pastures with Lolium x hybridum Hausskn and Medicago sativa L. The soil and pastures samples collected from plots irrigated with river water contaminated with heavy metals at a depth of 0-20 cm. The content of Pb determined by the atomic absorption spectrophotometry. The results showed the lead concentrations in soil in the range of environmental quality standards for soils according to Peruvian regulations. In the soil with L. x hybridum and M. sativa the average content of lead was 57.17 ± 6.29 mg.kg-1 and 57.19 ± 8.99 mg.kg-1; in the above-ground tissues were 1.17 ± 0.69 mg.kg-1 and 1.62 ± 0.68 mg.kg-1, respectively. In addition, no significant differences were observed in the Pb content in the soil and plant tissues. The bioconcentration factor (BCF) in the above-ground tissues of L. x hybridum and M. sativa was less than one and they were not significant. Therefore, irrigation with long-term contaminated water is not a concern for the farmers in the Mantaro Valley.

2

Heavy Metals in Soils from High Andean Zones and Potential Ecological Risk Assessment in Peru’s Central Andes

100%

Mendoza E. O. , Custodio M. , Ascensión J. , Bastos M. C.

Journal of Ecological Engineering

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2020

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tom Vol. 21, nr 8

108--119

EN

Soil is exposed to heavy metals that are associated with the anthropogenic activities, and is currently an environmental and food safety problem. The concentration and source of heavy metals in soils, the level of contamination and the potential for ecological risk in high Andean ecosystems were evaluated. The soil samples were collected from the surface part in which Andean crops were sown and the concentration of As, Cd, Pb, Fe and Zn was quantified. The concentrations of heavy metals in soils did not exceed the threshold of the national and international standard, while As, Pb and Zn exceeded the values of the background. The contamination factor (CF) values showed a high level of contamination for As and moderate for Pb and Zn. The geoaccumulation index (Igeo) values showed that As had the highest load of accumulated pollutants in soils by anthropogenic contribution. A moderate degree of contamination (CD) was found in 61.5% of the sampling sites. The potential ecological risk index (RI) showed that the soils of the study area presented a moderate to low potential ecological risk, and As was the main pollutant in high Andean soils. As, Pb and Zn occurring in high Andean soils mainly originated from human activities such as agricultural practices, whereas Fe mainly originated from the parent material of the soil. The effects of the use of organic and inorganic fertilizers on the accumulation of heavy metals in and Andean agricultural products must be analyzed and verified to protect the health of the inhabitants and the environment.

3

Ecological Risk Assessment for Heavy Metals in Agricultural Soils Surrounding Dumps, Huancayo Province, Peru

75%

Orellana-Mendoza E. , Acevedo R. R. , Huamán C. H. , Zamora Y. M. , Bastos M. C. , Loardo-Tovar H.

Journal of Ecological Engineering

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2022

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tom Vol. 23, nr 6

75--89

EN

Contamination generated by dumps is an environmental problem because the soils around the dumps are used for the cultivation of agricultural products and pastures, and could constitute a threat to human health. The contamination index and ecological risk potential for heavy metals in agricultural soils surrounding the solid waste dumps in Agua de las Vírgenes (AV) and El Eden (ED) in Huancayo were evaluated. The concentration of heavy metals in the soils was measured using an inductively coupled optical emission spectrophotometer. The average concentration of As, Cd, Cr, Pb, Cu, Fe and Zn in the soils was 25.77, 1.03, 6.09, 112.07, 48.52, 53733.33 and 349.10 mg/kg in AV and 14.35, 0.28, 2.85, 123.01, 57.47, 36137.50 and 414.31 mg/kg in ED respectively. The mean values of the contamination factor for As determined a very high soil contamination status at both sites. The order of mean Igeo values was As> Cd> Pb> Zn> Cu> Fe> Cr. The soils are strongly enriched with As and Cd. The highest risk index was for Cd, with a higher contribution to the overall potential risk index. The principal component analysis explained that 71% of the data set and the identified sources of heavy metals are the varied composition of wastes in general and crop irrigation with wastewater. In general, agricultural soils are characterized for a level of ecological risk that varies from high to very high. Among the measured heavy metals As, Cd and Pb pose significant health risks. Continuous monitoring of the level of contamination of soils affected by dump leachate and wastewater irrigation is suggested.