Assessing the genotoxicity of traffic-related air pollutants by means of plant biomonitoring in cities of a Brazilian metropolitan area crossed by a major highway

• We evaluated the air quality in residential areas near intense vehicular traffic highways in five cities of a metropolitan area.
• NO2, PM2.5 and the pollen abortion assay were assessed in this study.
• Results were associated with the city location in relation to the regional major highway.
• We found strong positive correlation between NO2 and PM2.5, as well as pollen abortion and PM2.5.
• Cities crossed by the major highway showed elevated levels of traffic-related air pollutants and increased genotoxic damages.

The aim of the present study was to evaluate the air quality in residential areas near highways with heavy vehicular traffic in five Brazilian cities by measuring markers of vehicular pollution and to assess the genotoxic effects of these pollutants by pollen abortion assay.Porto Alegre, Novo Hamburg, Canoas, Sapucaia do Sul and Itapuã were the cities chosen for this study. The biomonitoring assay performed was pollen abortion in Bauhinia variegata. Concentrations of atmospheric NO2 and PM2.5 were determined by passive monitoring and active monitoring, respectively.Results were associated with the city location in relation to the regional major highway. Levels of PM2.5 and NO2 as well as pollen rate were high in Porto Alegre Novo Hamburgo and Canoas compared with Sapucaia do Sul and Itapuã (P < 0.001). A strong positive correlation was found between NO2 and PM2.5 (ρ = 0.73; P = 0.013) and pollen abortion and PM2.5 (ρ = 0.90; P = 0.02).The cities crossed by the major highway had elevated levels of traffic-related air pollutants and increased genotoxic damages. Air pollution is a common problem in the cities in the metropolitan area of Porto Alegre (MAPA) as they are located near busy highways and is not limited to the main city center. Thus, pollen abortion assay is an effective tool for air pollution monitoring in multiple cities.