TITLE:
Analysis of Benzene Exposure Levels on Commuters Traveling within the Metropolitan Area of Costa Rica
AUTHORS:
Wendy Villalobos-Gonzalez, Germain Esquivel-Hernandez, Ricardo Sanchez-Murillo, José Leonardo Corrales-Salazar, Juan Valdes-Gonzalez
KEYWORDS:
Costa Rica, Benzene Exposure Levels, Solid Phase Microextraction (SPME), Traffic Hours, Commuters Exposure
JOURNAL NAME:
Open Journal of Air Pollution,
Vol.4 No.1,
March
24,
2015
ABSTRACT: This study reports the benzene exposure levels of commuters traveling
within the metropolitan area of Costa Rica using personal cars, buses, and
urban trains. 47 in-vehicle samples were collected in the 2014 wet season under
three different driving conditions: rush hour traffic, normal traffic and weekends. Samples were collected in
Tedlar bags and analyzed using 75 μm carboxenpolydimethylsiloxane (CAR/PDMS)
and gas chromatography with flame ionization detection (GC-FID). Additionally,
duplicate samples were collected on adsorption tubes filled with Tenax TA and
analyzed by thermal desorption (TD) and GC-FID. Results indicate that travelling
in cars and buses under rush hour conditions exposes commuters to statistically
equal average benzene concentration of 48.7
and 51.6 μg/m3, respectively. Average benzene levels in urban trains
(33.0 μg/m3) were measured only during morning rush hours.
Greater benzene levels in buses than personal cars concentrations may be attributable
to the immersion of traffic-related emission within the bus cabins.
Factors, such as the driving pattern, the number of vehicles on the route, the
road infrastructure, and the prevalence of gasoline-fueled vehicles in Costa
Rica, may increase ambient benzene concentrations. Benzene levels inside
car cabins reported in this study are in the range of those reported in other
urban areas; however, the corresponding concentrations inside buses and urban
trains (rush hour only) are higher than previously published exposure levels.