Neutron Activation Analysis for the multielemental determination and analysis of biomonitors (Thillandsia recurvata) for the study of polluting agents in the valley of Mexico

CERVANTES, M.L.; PALACIOS, J.C.; ORTUÑO, C.; JASAN, R.C.; PLÁ. R.; WANNAZ, E.D.

Buenos Aires

Workshop; 5th International Workshop on Biomonitoring of Air Pollution; 2009

CNEA

In this work, we use neutron activation analysis for the multielemental determination in biomonitors (Tillandsia recurvata). These results were used to determine major pollutants in the air of the Metropolitan Zone of the Valley of Mexico (ZMVM). We also found also certain elements present in vegetable species that could define some limits in order to diagnose a possible damage to the vegetation and its probable impact to the human health. The samples of Tillandsia recurvata (L.) were collected in the town of San Juan Teacalco in the State of Mexico, which was considered the control point due to its characteristics. The samples were distributed in the ZMVM in some stations that belong to the System of Atmospheric Monitoring (SIMAT) of the Office of the Secretary of Environment of the Government of Mexico City. The samples were exposed six months from August of 2002 to January of 2003. The elementary concentration was determined by means of Neutron Activation Analysis. After a radioactive decay period from 6 to 30 days the concentration of the following elements was calculated: As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb and Zn. The data were evaluated for correlation analysis, main components analysis and mapping. Some of the determined elements; are essential components of the plants. But we also found elements that come from industry, vehicles, soil and metallurgic industry. These elements and its concentration have variation from season to season mainly those founded in the north area of Mexican Valley.