Ambient air levels of volatile organic compounds in Latin American and Asian cities

Abstract

Levels of volatile organic compounds (VOCs) have been measured during short monitoring campaigns in four cities in Latin America; Caracas (Venezuela), Quito (Ecuador), Santiago (Chile), São Paulo (Brazil), and two cities in Asia; Bangkok (Thailand) and Manila (Philippines). The aim of the study was to identify typical levels of VOCs in these cities where monitoring of this unregulated but important group of pollutants has rarely been conducted. Levels monitored were relatively high in comparison to typical European and US levels. Mean benzene levels ranged from 5–18μg/m 3 and toluene from 15–186μg/m 3. VOC levels in the Latin American cities were similar and considerably lower than those measured in the two Asian cities. Levels in Quito were the lowest of all the cities studied and this may reflect its high altitude which allows the use of fuels with a low aromatic content. The relative abundances of the different VOCs monitored and the ratios between different VOCs are largely consistent with vehicles being the predominant source of VOCs in these cities. The levels of VOCs measured during this study were generally higher than proposed UK standards and as such represent a direct health risk to the inhabitants of the cities. High levels of VOCs will also affect the incidence and severity of photochemical episodes with further consequences for human health and the environment.