- Traffic exhaust is an important source of air pollution. This exposure assessment study examined traffic related air pollution in Curitiba, Brazil, and is particularly relevant due to 75% of the population using diesel public transportation. Traffic density was tabulated, and vehicle-type was distinguished based on their fuel type (diesel or gasoline) at four sampling locations in Curitiba. Concurrently, fine particulate matter (PM2.5) ambient air levels were monitored and recorded using AirBeam, a low cost PM2.5 monitor. By performing linear regression analyses, it was found that there exists a moderate to strong correlation between traffic density and PM2.5 concentration (R2=0.74). Rain events played a significant role in removing suspended particulates from the air (R2 increased 0.6333 once the sampling location affected by a rain event from removed from the data set). Modeling the asymmetrical impact that diesel (y=0.3543x+7.7634) and gasoline (y=0.0798x+3.3743) vehicles have on PM2.5 resulted in a slope ratio of 4.4, interpreted as 1 diesel vehicles having a similar impact as 4.4 gasoline vehicles on pollutant concentration.