Chemical composition of the haze in Malaysia 2005

A study of the chemical composition of the haze was conducted in two areas: Klang Valley and Malacca in Peninsular Malaysia, from July to September of 2005. The data is based on the reports of the air quality monitoring for particulate matter (PM10), pH of rainwater, anions (NO3−, SO42−, Cl−), cations (NH4+, Na2+, Ca2+, K+, Mg2+), heavy metals (Fe, Zn, Pb, Mn, Cu, Ni) and a meteorology parameter, the wind speed. The monthly concentrations of PM10 for the Klang Valley ranged from 35.90 to 104.46 μg m−3 whilst in Malacca the concentration ranged from 35.80 to 54.30 μg m−3 which was over the permitted level of 50 μg m−3 for the time period of a month as stipulated by the Department of Environment Malaysia (DOE). The pH of rainwater collected in the Klang Valley ranged from 4.26 ± 0.12 to 5.45 ± 0.58, while in Malacca the pH varied from 4.35 ± 0.20 to 5.43 ± 0.12. The mean concentrations for NO3-, SO42-, Cl-, NH4+, Ca2+, Na2+, K+, Mg2+ for three months in the Klang Valley were 46.40 ± 11.16 μeq L−1, 34.84 ± 9.82 μeq L−1, 12.34 ± 4.13 μeq L−1, 29.28 ± 11.02 μeq L−1, 8.92 ± 0.88 μeq L−1, 8.18 ± 1.00 μeq L−1, 2.08 ± 0.34 μeq L−1, 1.38 ± 0.24 μeq L−1, respectively, whilst in Malacca, the mean concentrations were 24.46 ± 6.99 μeq L−1, 28.4 ± 7.24 μeq L−1, 27.32 ± 7.36 μeq L−1, 30.92 ± 1.26 μeq L−1, 4.10 ± 2.56 μeq L−1, 21.44 ± 7.54 μeq L−1, 3.18 ± 1.82 μeq L−1 and 1.54 ± 1.66 μeq L−1, respectively. These values were lower than the non haze period (January to March and April to June) except for the Cl- ion which recorded the highest anion in Malacca. However, the mean values were similar for the period from October to December. The mean concentrations of metals showed that Cu > Ni, whilst in Malacca, in descending order, were Fe > Zn > Cu > Mn > Pb > Ni.