摘要：Problem statement: In keeping abreast with Malaysia’s rapid economic development and to meet the nation's aspiration for an improved quality of life, clean-air legislation limiting industrial and automobile emissions was adopted in 1978. Approach: Yet, to this day, air pollution from both sources still poses a problem for the nation. In order to predict the status of future air quality in Malaysia, a Box-Jenkins ARIMA approach was applied to modeling the time series of monthly maximum 1 h carbon monoxide and nitrogen dioxide concentrations in the east coast states of Peninsular Malaysia, i.e., Terengganu, Pahang and Kelantan, respectively, as well as to a comparison with the representative west coast state represent of Hulu Kelang. Results: In all the states, both carbon monoxide (CO) and Nitrogen dioxide (NO2) concentrations have shown a fairly consistent upward trend since 1996. Nevertheless, the values forecast to 2016 for all states excluding NOx for Hulu Kelang did not exceed the permissible values given by either NAAQS or DOE Malaysia which are 35 and 30 ppm, respectively, at a 1 h average for CO and 0.053 and 0.17 ppm, respectively, for NOx. Conclusion/Recommendations: The forecasting values of each of the concentration parameters are still within a well-conserved condition as they do not exceed the limits of either NAAQS or DOE Malaysia excluding the values for nitrogen dioxide for Hulu Kelang.
关键词：ARIMA forecasting; time series; carbon monoxide; nitrogen dioxide; east coast peninsular Malaysia
