Bangkok, one of the largest cities in Southeast
Asia, has a population of more than 10 million.
Vehicle air pollution is a serious environmental
problem on the roadsides in the Bangkok area because
of a limited number of streets and increasing
number of registered vehicles each year. The
groups of people who are most at risk of trafficrelated
air pollutants are street vendors. Working
day after day selling their goods on the sidewalks
along the streets, there are approximately more
than 28,000 street vendors in the Bangkok area.
road side areas of Bangkok.11-12
So far little research has been conducted to study
the adverse health effects of traffic-related air pollutants
among street vendors. This study intends to
compare the level of traffic-related air pollutants,
i.e. fine particulate (PM2.5), sulfur dioxide (SO2),
nitrogen dioxide (NO2) and carbon monoxide (CO),
and the 61-day daily reported respiratory and other
health symptoms by street vendors in a representative
roadside area and a representative residential
area.