Hong Kong Chief Executive Donald Tsang said Monday an education campaign will start this month to encourage the public and the business sector to help clean the air in the city.

Speaking at the Legislative Council, Tsang said the government will endorse the Clear Air Charter initiated by the business sector and will launch a Dress Down Campaign this summer.

"In response to the green groups' appeal, the Civil Service Bureau will issue a reminder later today to encourage colleagues to dress in casual, but appropriate, attire in summer. I hope the private sector will also encourage their staff to dress casually in summer wherever appropriate," Tsang said.

All government bureaus and departments have raised the air-conditioned room temperature to the standard 25.5 degrees Celsius in green groups' appeal this summer.

According to experts, the move can save about one billion units of electricity a year, which means the public can save 900 million HK dollars (115.4 million U.S. dollars) in electricity tariffs. It will also help cut 700,000 tons of carbon dioxide, 2,400 tons of sulphur dioxide, 1,200 tons of nitrogen oxides and 100 tons of respirable suspended particulates annually.

Since improving air quality requires the whole community's participation, Tsang said he hoped citizens could make use of public transport, turn off idling engines, choose electric appliances with higher energy efficiency, switch off home appliances such as televisions and lights when not in use before leaving a room, choose electrical appliances covered by the Energy Efficiency Labeling Scheme and avoid using goods with volatile organic compounds such as hair spray and air refreshener.

In recent years, the government has done a lot to improve air quality. According to the government figures, major pollutants in the air have been reduced compared with 1997. In 2004, the concentration of respirable suspended particulates and nitrogen oxides recorded at roadside air quality monitoring stations fell by 9 percent and 24 percent respectively. Except for sulphur dioxide, emissions of major pollutants dropped between 16 percent and 28 percent.

Four years ago, Hong Kong set targets with the Guangdong Provincial government that would see, by 2010, a significant reduction in emissions of four major air pollutants in the region.To achieve this target, Guangdong and Hong Kong have put in place a series of measures.

Guangdong is adopting measures to expand the use of cleaner fuels, restrict the level of sulphur in fuels, phase out small-scale and highly polluting power plants, install desulphurization systems in generation units, and strictly control vehicle emissions.

In Hong Kong, power plants are still the major source of pollution in terms of emissions, with the amount of sulphur dioxide released accounting for 92 percent of the total. The government has imposed emission caps in the licenses of the power plants. In the long run, the government expects to require power companies to reduce emissions drastically and impose penalties for failing to meet the emission caps through the new Scheme of Control Agreements after 2008.

To meet the 2010 emission reduction targets, the government has also implemented other measures, including tightening the specifications for petrol to the Euro IV standard; introducing Euro IV emission standards to newly registered vehicles; requiring the installation of vapor-recovery systems at petrol stations; controlling volatile organic compounds emissions from specific products; and introducing a mandatory energy efficiency labeling scheme covering room coolers, refrigerators and compact fluorescent lamps.

"Hong Kong is a small place. Air pollution affects everyone regardless of age, wealth, status and profession. So, citizens should shoulder the responsibility together. I hope all Hong Kong people, the local business community, and businessmen investing in the Pearl River Delta Region fully support the activities to be launched by the Environmental Protection Department for a blue sky, " Tsang said.