A Cloudy View for the Region (HKEPD Environment Hong Kong 1999) http://ww.epd.gov.hk/epd/misc/english/annualrpts/textonly/annual_rpt1999/ch2_2.htm l By Dr. Alain Lam

The air hanging over the Pearl River Delta is like a witch's brew, bubbling with chemicals that cloud the view, turn the rain to acid and create long-term health problems for people. But instead of lizard's tails and swamp water, this brew is made up of emissions from vehicles, power plants and factories around the region.

Image of a clear view and clouded view: what air pollution does to visibility.

Hong Kong and Guangdong officials, like their citizens, have watched with concern as the problem worsened during the 1990s. They realise they cannot act alone because air pollution respects no boundaries, so they have embarked on a joint effort to try to clear the air.

Their first step is a joint study announced in 1998 to pinpoint the sources of air pollution and come up with solutions to a problem that literally prevents Hong Kong and Guangdong from seeing each other.

Visibility has declined markedly since 1991, according to the Environmental Protection Department (EPD). The likelihood that you can see less than eight kilometres away - the equivalent of seeing no further than Tsing Yi Island from the Peak - has almost doubled from about 4.4 per cent of the time to 8.2 per cent. That does not include rainy days or days with high humidity.

Poor visibility on dry, clear days is the result of smog. Smog is created when lots of different pollutants, from vehicles, factories, landfills and power plants, combine under sunlight. Ozone is usually taken as an indicator for smog and ozone levels in Hong Kong have risen almost 50 per cent since 1990.

Chart of levels of ozone, a major component of smog, are up 50 per cent since 1990. Chart of the chances of a cloudy smog-filled view have doubled, since 1995.

Hong Kong has already taken steps to control much of its air pollution. Its power companies have installed scrubbers in their chimneys to remove some of the pollution, its factories have to control their pollution and vehicles increasingly face stricter controls. Guangdong is also taking steps in these directions.

Of course, more work needs to be done on both sides. But since the problem is a cross-boundary one, it needs a cross-boundary solution.

Work on the joint study will start in mid-1999 and focus on Hong Kong and the Pearl River Delta Economic Zone which includes Shenzhen, Guangzhou, Zhuhai and other central counties.

The EPD and the Guangdong Environmental Protection Bureau will divide the work based on their main worries: Hong Kong will investigate air pollution from motor vehicles, which threatens health, while Guangdong will look into acid rain which is affecting farming and other activities in the province.

Both sides already monitor air pollution, so first they will share this information. Then they will jointly measure air quality at different locations and altitudes and gather relevant data, such as the distribution of transport networks and industry, the forecast growth in transport, population, energy and other areas, as well as the existing laws, technical standards and policies for controlling air pollution.

With all that information, they expect to predict air pollution into the future and, most importantly, recommend pollution prevention and control options. The final report will be submitted to the Hong Kong Guangdong Environmental Protection Liaison Group in 2000.

There is still a long way to go to clear the smoke screen of air pollution which has divided Hong Kong and Guangdong for a decade. Hopefully, we will be able to see each other clearly again when our joint actions reach success.