< span风格= "字体大小:14 px”> < span风格=“字体类型:Arial, Helvetica,无衬线”>的背景。墨西哥has public health problems due to its inadequate systems for sewage treatment, sanitation means and low income and economic levels, which influence the increase of disease manifestation. Objective.Determine seasonal variations, frequency and distribution of enterobacteriaairborne aerosols incoming from “San Juan de Dios” River. It is worth mentioning that, these bacteria possess antimicrobial and heavy metals resistance, such as to Pb, Cr, and Cd, and their hemolytic profile.Materials and Methods.Therefore, an ecological study was conducted during the seasons of summer and autumn.  Results.822 enterobacteria strains were collected,from which 723 were identified under 18 genres and 40 species, from which 63.90% corresponding to summer and 36.09% to the autumn season. As a critical sampling, point number 2 showed to have 265 colony forming units during summer and 124 during autumn. 48 strains had beta-hemolytic profile; the 68.57% of identified strains showed resistance to more than two antibiotics in reference of Pb, Cd and Cr to which also showed resistance. Conclusion. Enter bacteriological recoverability shows values above 1x103 Gram negative/m3 of air, as risk factors for human health; which allows (due to their characteristics) their implementation as useful indicators of risk exposure.