Air pollution during the haze event of 2005: The case of Perai, Pulau Pinang, Malaysia

The transboundary haze from the biomass burning in Sumatera and Kalimantan brought about a haze emergency on 11 August 2005 in the districts of Kuala Selangor and Kelang, on the western coast of Peninsular Malaysia. A study on how far this haze phenomenon had influenced the air quality in Perai, Pulau Pinang was conducted whereby the state of air pollutants such as carbon monoxide, nitrogen dioxide, sulphur dioxide, ozone, and particulate matters of size less than 10 microns (PM10) was investigated. The monthly PM10 concentrations revealed two distinct distributions, where values of more than 80 μg m-3 occurred from January to July but were lower than 60 μg m-3 from August to December. The analysis was carried in three temporal durations that ranged from January to December, January to July and August to December. The multivariate regression analysis showed that rainfall and wind speed contributed to 5.3% of the PM10 concentration from January to December. The correlation analysis showed a weak and inverse relationship between rainfall and the PM10 concentration. The correlation coefficients during the three temporal periods were -0.188, -0.184, and -0.164, respectively. Wind speed also showed a very weak influence on the PM10 concentration where the correlation coefficients were 0.152 (January to December), 0.042 (January to July), and 0.127 (August to December), respectively. In conclusion, the haze phenomenon during August, 2005 did not severely affect the air quality in Perai since the PM10 concentration did not exceed 70 μg m-3.