Temporal Characteristics of Airborne Particulate Matter in Phnom Penh, Cambodia

Particulate matter of less than 10 microns (PM-10), has been identified as a critical airborne pollutant of most Asian cities, and is often attributed to vehicle traffic. PM-10 is not routinely monitored in Phnom Penh, Cambodia. Using a particle counter, PM-10 was monitored along Phnom Penh roads creating road-side temporal profiles. The 'commuter profile' exhibited high PM-10 counts in the morning and late afternoon. The 'business district profile' exhibited high PM-10 counts in the late-morning/early-afternoon. The PM-10 particle counts were converted to PM-10 mass measurements (μg/m3). The PM-10 mass measurements exceeded the WHO daily standard of 50 μg/m3, while it approached and sometimes exceeded (during periods of peak traffic) the U.S. EPA standard of 150 μg/m3.