Distribution of Trace Elements in Egg Samples Collected Near Coal Power Plants
- Érico Marlon de Moraes Flores and
- Ayrton Figueiredo Martins
The intensive use of mineral coal for thermal power generation is known to cause severe damage to the regional environment. The emission of cadmium (Cd), lead (Pb), and fluoride (F) compounds into the atmosphere may lead, under certain conditions, to serious contamination of primary matrices in the biosphere and even of foodstuffs. In the present study, egg samples were collected from nonconfined hens (Gallus domesticus) over a period of 2 yr in the vicinity of two of the major coal power plants (Candiota and Charqueadas) in the state of Rio Grande do Sul (RS), Brazil. The constituent parts of the samples (yolk, albumen, and shell) were solubilized with acid in a teflon-lined pressurized bomb after an appropriate heating step. The Cd and Pb were determined by graphite furnace atomic absorption spectrometry using Pd/Mg nitric solution as chemical modifier. Fluoride was determined by direct ion-selective electrode potentiometry. Cadmium concentration in the samples from both regions ranged from <0.01 (albumen) to 0.10 (yolk) mg kg−1, whereas Pb and F concentrations ranged from 0.16 (shell) to 3.16 (yolk) and from 0.06 (yolk) to 1.75 (shell) mg kg−1, respectively. A comparison with the higher obtained mean values for reference samples (Cd < 0.02 mg kg−1, shell; Pb = 0.11 mg kg−1, yolk; and F = 0.07 mg kg−1, shell) indicates a significant environmental contamination with Pb and F in the regions of Candiota and Charqueadas. A relative Cd and Pb enrichment in the yolk was also confirmed, whereas F preferentially concentrated in the shell.
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