Impact of the atmospheric contamination on the content of heavy metals of water leaf (Talinum triangulare) harvested in urban and peri-urban farmlands

Abstract

The contents of cadmium, copper, manganese, nickel and lead were determined in water leaf (Talinum triangulare (Jacq.) Willd.) in different urban and peri-urban farmlands from Havana, which were previously classified according to the qualitative contamination of the air with the objective to evaluate the influence of air quality on the concentration of these metals in the plant.
Determinations of these metals were made by atomic absorption spectrometry using sonication with 1 mol·L–1 nitric acid during 1 hour to take the sample to aqueous phase. Values obtained ranged from 0,1 to 0,13 ppm for cadmium; 0,89 – 1,39 ppm for copper; 18,25 – 30,41 ppm for manganese; 0,73 – 1,49 ppm for nickel and 0,52 – 0,7 ppm for lead. The Principal Component Analysis (PCA) of the results showed that the grouping of samples according to their heavy metals content followed a pattern similar to that of the classification of farmlands as to air pollution, used as criterion to conduct the study and thus PCA
can be considered as an estimator of the atmospheric ontamination by heavy metals of crops for further works.