Banca de DEFESA: RAYANA DA ROCHA SARMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAYANA DA ROCHA SARMENTO
DATE: 06/07/2022
TIME: 09:00
LOCAL: Remoto
TITLE:

Geochemical Fractionation of Zn, Ni and Cd in Soils of the Mountain Region - RJ: Reference Values for Bioavailability and Assessment of Contamination in Areas Cultivated with Leafy Vegetables

KEY WORDS:

Heavy metals;bioavailability index;pollution index

PAGES: 102
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

The intensive use of agrochemicals and inadequate soil management in areas of intensive cultivation can result in serious problems of soil, groundwater and food contamination. Where pollutants such as heavy metals, when deposited in the soil, can enter the food chain. The objective of this work was to establish the Bioavailability Index (BI) for Zn, Ni and Cd for the Serrana Region of Rio de Janeiro and to evaluate the contamination and the risk caused by Cd, Zn and Ni of cultivated areas with leafy vegetables based on in the established index and in the IP. Soil and plant samples were collected in the areas of Nova Friburgo and Petrópolis, located in the mountainous region of Rio de Janeiro, in areas where lettuce, parsley and kale are produced. To determine the pseudototal levels of heavy metals, the EPA 3050B method, described in USEPA (1996) was used. Geochemical fractionation was performed by the sequential extraction method based on the BCR Community Bureau of Reference method described by URE et al. (1993), with modifications adding the water-soluble fraction. The pollution indices (PI) of heavy metals Zn, Ni and Cd were calculated based on the Quality Reference Values (VRQ's) and the bioavailability indices (IB) were calculated based on the Bioavailability Reference Values (VRBs) established for the mountainous region of the state of Rio de Janeiro. The IP of the metals Zn, Ni and Cd showed that the enrichment of the elements occurred mainly by anthropogenic actions with the addition of P and Corg sources. These sources are due to the intense use of phosphate fertilizers and poultry litter in the study area. The BI of Zn and Ni showed that the bioavailability is lower when there are higher levels of Corg, Fe, Al and higher pH values. For Cd, both IP and IB of Cd are highly associated with soluble sources of fertilization. Soils corresponding to G1, generally showed higher levels of Al, Fe and O pseudototal, higher levels of Corg, Ca, and higher pseudototal levels of Zn, Ni and Cd. Soils related to G2 showed higher contents of pseudototal Mn, Mg, pH, altitude, elevation and slope. In areas of intensive agriculture, the contribution of the relief in the distribution of metals was observed, with the highest Zn, Ni and Cd contents being found in areas with lower elevations, differently from what was found for areas with higher elevations. In G1 all the studied elements present IP above 5, where Zn, Ni and Cd characterized a severe contamination. For G2, only Cd characterized a severe contamination, Zn and Ni characterized low contamination. In G1, only Cd has the highest IB, with an average indicating severe risk. Zn and Ni showed higher BI in G2, which indicated low risk. The average levels of Cd in fresh cabbage samples exceed the maximum limit established by the Brazilian Regulatory Agency. Leafy vegetables differ in terms of Cd, Zn and Ni contents in their composition. The risks to human health associated with the consumption of leafy vegetables produced in the study region did not exceed the considerable intolerable limits.

BANKING MEMBERS:
Interno - 387263 - NELSON MOURA BRASIL DO AMARAL SOBRINHO
Externa à Instituição - FABIANA SOARES DOS SANTOS - UFF
Externo à Instituição - FARLEY ALEXANDRE DA FONSECA BREDA