THE recent haze may still be fresh on people's minds, but Singaporeans have mostly enjoyed clean air over the last 40 years, Environment and Water Resources Minister Yaacob Ibrahim said on Tuesday.

This, despite challenges posed by the need to rapidly industrialise the city-state, which in the years after independence, lacked proper homes and blue-chip industries needed to sustain a young country.

In the last four decades, the Pollutant Standard Index (PSI) - used here to measure air quality - has been in the 'good' range on nine out of 10 days, said the minister, who opened the Better Air Quality 2010 Conference at Suntec Convention Centre.

On most of the other days, the index crept into the 'moderate' range, while only on three occasions in the last 10 years did it hit the 'unhealthy' range.

This happened in 1997, 2006 and last month, when severe haze blanketed the island, caused by smoke blown this way from neighbouring Indonesia. A PSI reading of over 100 is considered unhealthy.

He said: 'From the planning stage, such as locating pollutive industries away from residential areas, down to mandating and enforcing strict emission standards, we have been strike a fine balance between supporting economic development and ensuring a high quality of life.'

Air here 'mostly clean'