Urban air pollution and genotoxic damage in street vendors: a longitudinal repeated-measures panel study
Boscolli Barbosa Pereira1, Thalita Pessoa Campos1, Isadora Gomes de Souza2
1Federal University of Uberlândia, Institute of Geography, Geosciences and Collective Health, Santa Mônica Campus, Avenida João Naves de Ávila, 2121, Uberlândia, Minas Gerais, 38.408-100, Brazil.
Abstract:
Urban air pollution remains a major environmental health challenge, yet longitudinal evidence linking particulate matter exposure to genotoxic biomarkers across contrasting climatic conditions remains limited. This study examined the association between particulate matter exposure, climatic season, and chromosomal damage in urban workers from Uberlândia, Brazil. A prospective repeated-measures panel study was conducted with 238 male participants who completed four sampling campaigns spanning rainy and dry seasons, including 116 street vendors working in the central urban area and 122 formal indoor vendors working in a reference area. Ambient PM1, PM2.5, and PM10 concentrations were monitored at seven fixed monitoring points, and genotoxic damage was assessed using the micronucleus (MN) assay in exfoliated buccal mucosa cells. Particulate matter concentrations varied significantly across campaigns (p < 0.001) and were consistently higher in the central urban work environments. MN frequency also showed significant temporal variation and was consistently higher among street vendors across all campaigns (p < 0.05), whereas binucleated cell frequency showed no significant temporal variation. In multivariable Poisson generalized estimating equation models accounting for repeated measurements and spatial heterogeneity, higher PM2.5 concentrations were positively associated with MN frequency during both the rainy season (IRR = 1.024 per 1 μg/m3 increase; 95% CI: 1.013-1.034) and the dry season (IRR = 1.026; 95% CI: 1.019-1.034). The PM2.5 x season interaction was not statistically significant (p = 0.378), providing no evidence that climatic season modified the association between PM2.5 and MN frequency. These findings demonstrate a consistent positive association between ambient PM2.5 concentrations and chromosomal damage across contrasting climatic conditions, alongside marked differences in particulate exposure and MN frequency between urban occupational environments. Integrating environmental monitoring with longitudinal human biomonitoring may provide a useful framework for urban environmental health surveillance.
