IN-VITRO INDUCTION OF ABNORMAL ANAPHASES BY CONTAMINATING ATMOSPHERICDUST FROM THE CITY-OF-MEXICALI, BAJA-CALIFORNIA, MEXICO

Mexicali dust (MD) is a mixture of particles of potassium aluminum sil icates (98%) and sodium dioxide (2%) that induces pulmonary damage und er experimental conditions, and is capable of inducing irt vitro chrom osomal alterations in exposed lymphocytes. It has been proposed as an atmospheric contaminant with pathogenic potential. Among the chromosom al alterations observed, numeric alterations were predominant. The pre sent study was designed to evaluate the capacity of MD to induce anaph asic 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 (27.4 1% with 20 mg/mL, 29.60% with 40 mg/mL and 37.10% with 80 mg/mL). Mult ipolar anaphases constituted the most frequent alteration (69.1 - 78.8 %), followed by lagging chromosomes (18.2 - 29.5%) and anaphasic bridg es (1.51-5.9%). The anaphasic alterations induced by MD showed differe nces in comparison to those observed with asbestos, especially for ana phasic bridges (10.4% vs. 1.51%, p < 0.05). The capacity of MD to indu ce alterations reported in the process of chromosomal disjunction coul d explain the numeric aberrations reported previously by the authors o f this paper. Therefore, these data support that MD could act as a cla stogenic agent.