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Introduction The World Health Organization (WHO) estimates that 1.5 billion urban dwellers live in areas with levels of outdoor air pollution above the maximum recommended limits (World Health Organization [WHO], [...], Street-level and rooftop (three-story building) concentrations of particulate matter ≤ 2.5 pm in diameter ([PM.sub.2.5]) were measured in downtown Trujillo, Peru, in July and August 2003 to determine the [PM.sub.2.5] concentration reduction on days with normal traffic conditions (32 days) versus a day when motor vehicles were temporarily banned from the downtown district (8:00 a.m. to 6:00 p.m., July 15) known as El Dia Sin Autos ('The Day Without Cars'). The mean 8:00 a.m. to 6:00 p.m. street-level [PM.sub.2.5] concentration during the motor vehicle ban (21.4 µg/[m.sup.3]; one day) was 49% lower than when vehicles were not impeded (42.2 ± 7.8 µg/[m.sup.3]--mean [+ or -] 1 standard deviation; 20 days). The rooftop monitoring station indicated a 20% decrease in [PM.sub.2.5] concentrations (24.8 ± 2.6 µg/[m.sup.3] vs. 19.9 ± 6.0 µg/[m.sup.3]) when motor vehicles were not present within historic downtown Trujillo. Temperature, relative humidity, and wind speed during the motor vehicle ban and during normal traffic were not significantly different (p > .05).

Street-level and rooftop (three-story building) concentrations of particulate matter ≠2.5 μm in diameter (PM[sub2.5]) were measured in downtown Trujillo, Peru, in July and August 2003 to determine the PM[sub2.5] concentration reduction on days with normal traffic conditions (32 days) versus a day when motor vehicles were temporarily banned from the downtown district (8:00 a.m. to 6:00 p.m., July 15) known as El Dia Sin Autos ("The Day Without Cars"). The mean 8:00 a.m. to 6:00 p.m. street-level PM[sub2.5] concentration during the motor vehicle ban (21.4 ug/m³; one day) was 49% lower than when vehicles were not impeded (42.2 ± 7.8 μg/m³ — mean ± 1 standard deviation; 20 days). The rooftop monitoring station indicated a 20% decrease in PM[sub2.5] concentrations (24.8±2.6 μg/m³ vs. 19.9 ± 6.0 μg/m³) when motor vehicles were not present within historic downtown Trujillo. Temperature, relative humidity, and wind speed during the motor vehicle ban and during normal traffic were not significantly different (p > .05). [ABSTRACT FROM AUTHOR]

Public transport vehicle drivers, especially in highly polluted or trafficked areas, are exposed to high levels of air pollutants. In this study, we assessed the influence of traffic on levels of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) in commercial bus drivers in Trujillo, Peru, by measuring the within-shift changes in the urinary whole weight and creatinine-corrected concentrations of the PAH metabolites. We measured personal PM(2.5) as a proxy of exposure to traffic emission. Urine samples were collected daily from two bus drivers and three minivan drivers in Trujillo, pre-, mid-, post-work shift and on days when the drivers were off work (total n = 144). Ten OH-PAH metabolites were measured in the urine samples. Drivers were also monitored for exposure to PM(2.5) (n = 41). Daily work shift (mean = 13.1 ± 1.3 hr) integrated PM(2.5) was measured in the breathing zones of the drivers for an average of 10.5 days per driver. The differences across shift in OH-PAH concentrations were not statistically significant except for urinary 2-hydroxyfluorene (2-FLU) (p = 0.04) and 4-hydroxyphenanthrene (4-PHE) (p = 0.01) and creatinine-corrected 4-hydroxyphenanthrene (p = 0.01). Correlation between pairs of hydroxy-PAHs (ρ = 0.50 to 0.93) were highest for mid-shift samples. Concentrations of PM(2.5) (geometric mean = 64 μg/m(3); 95% confidence limits = 52 μg/m(3), 78 μg/m(3)) is similar to those measured in many other studies of traffic exposure. There was significant change across work shift for concentrations of only two of the OH-PAHs (2-FLU and 4-PHE). Results indicate that the drivers may have had limited time for clearance of PAH exposure from the body between work shifts. Comparisons of the concentrations of creatinine-corrected hydroxy-PAH to those reported in other studies indicate that exposure of public transport drivers to PAH could be similar. By following the subjects over multiple days, this study gives an indication of appropriate exposure situations for the use of hydroxy-PAHs and will be beneficial in designing future occupational studies of PAH exposure.