In vitro induction of abnormal anaphases by contaminating atmospheric dust from the city of Mexicali, Baja California, Mexico

RESUMO

Mexicali dust (MD) is a mixture of particles of potassium aluminum silicates (98 percent) and sodium dioxide (2 percent) that induces pulmonary damage under experimental conditions, and is capable of inducing in vitro chromosomal alterations in exposed lymphocytes. It has been proposed as an atmospheric contaminant with pathogenic potential. among the chromosomal alterations observed, numeric alterations were predominant. The present study was designed to evaluate the capacity of MD to induce anaphasic changes in the Balb c 3T3 cell line. Chrysotile asbestos was used as a positive control. MD was found to induce abnormal anaphases, and the percentage of abnormalities increased as the dose increased (27.41 percent with 20 mg/mL, 29.60 percent with 40 mg/mL and 37.10 percent with 80 mg/mL). Multipolar anaphases constituted the most frequent altertion (69.1 - 78.8 percent), followed by lagging chromosomes (18.2 -29.5 percent) and anaphasic bridges (1.51 - 5.9 percent). The anaphasic alterations induced by MD showed differences in comparison to those observed with asbestos, especially for anaphasic bridges (10.4 percent vs. 1.51 percent, p<0.05). The capacity of MD to induce alterations resported in the process of chromosomal disjunction could explain the numeric aberrations reported previously by the authors of this paper. Therefore, these data support that MD could act as a clastogenic agent