RAPID growth and the advent of a cheap domestic-made car are wreaking havoc with Malaysia's air. An official report has confirmed what Malaysians had already judged for themselves. The study on which the report was based found higher acidity in rain falling on urban and industrial areas, while toxic lead readings remain at the top end of the scale. According to the latest air quality report by the Malaysian Meteorological Service, the acid rain was caused largely by emissions from factories and motor vehicles. It said acid rain was most severe in September last year when much of Southeast Asia was covered with a haze caused mainly by forest fires in Indonesia. But high levels were widespread all the year. Meteorological service environmental studies director Leong Chow Peng said the overall situation had worsened last year. Acid rain was more serious on the fast-developing west coast of peninsular Malaysia than on the east coast. The three main areas of severe air pollution are the Klang Valley - including Kuala Lumpur - Penang and southern Johor, all major industrial centres. Rain in these areas had a pH value of 4.8 compared to the national average reading of 5.2. The lower the figure the higher the acidity. Acid rain is caused mainly by the emission of sulphur dioxide and nitrogen oxides from power plants, motor vehicles and factories, and by burning of agricultural waste. The meteorological service found the highest concentration of toxic lead in Petaling Jaya, Kuala Lumpur's satellite town. It said the rising levels reflected the increase in vehicle use and rise in industrial sources against the backdrop of strong economic growth, which is concentrated in the Klang Valley. The new Proton car has contributed to the jump in vehicle sales from 100,000 five years ago to 200,000 last year. A total of 1.6 million vehicles are moving in the Klang Valley every day.