Particulate matter concentration level inside air conditioned public bus in klang valley / Mohd Luqman Hakimi Azmi

Particulate Matter exposure has been a concern in our daily lives such as our place of work, environment and home. The Department of Environment is responsible for controlling environmental pollution, while the Department of Occupational Safety and Health is responsible for exposures of workers in the workplace environment. However, less consideration has been given to the micro environment we are living in such as public transportation and other places where we may be exposed to and where we spend some time. This study was done to measure the concentrations of the PMio and PM2.5 in the public bus transportation. The measurements were done by using TSFs DustTrak Aerosol Monitor and Quest EVM-7/CO Advanced Particulate and Air Quality Monitor with PID with logging interval of 30second and run for 30 minutes each sample which represents the exposure time for the bus commuters. One way Anova was used to analyse the effects of travelling periods (morning: 8.00am-12.00pm and afternoon: 12.00-7.00pm) on the concentration of the particulate matter in buses. Post hoc analysis of Kramer Multiple Comparison was used to analyse the groups involved. Independent t-test was used to analyse types of bus as a factor that contributed to the high concentration of particulate matter. Descriptive data and inferential data showed that both PMio and PM2.5 are affected by the type of bus and the travelling period. The study found that the highest exposure for both PMio and PM2.5 are at the morning peak time for the Metro Bus (n=24) with PMio mean exposure=198.8±....ug/m3 and PM2.5=67.08±20.73ug/m3 while for Rapid KL (n=26) the PMi0=156.54±35.21ug/m3 and PM2.5=41.81±7.54ug/m3. One way Anova result (p<0.001) with significance difference (p<0.05) between AM Peak travelling time and the PM peak travelling period. Independent t-test (p<0.001) showed a significance difference (p<0.05) between Rapid KL Bus and Metro Bus for both PMio (mean differenced98.8±5.63ug/m3) and PM2.5 (mean difference=97.6±5.771ug/m3) concentrations. This phenomenon could be due to the microclimate inversions and high density of PM concentrations in the microenvironment. In Malaysia there are no specific legislation on the concentration of particulate matter in vehicles for PMio and PM2.5. However as a working place for the drivers the USECCHS, Regulations 2000 was complied with PMio=3mg/m3 and no standards set for PM2.5.