When some of the world's most influential and powerful business leaders were here last month for the first Council of International Advisers, their host, Chief Executive Tung Chee-hwa, proudly took them on a helicopter ride to view the city. His guests were appalled. From their cockpit in the sky, they had a fish hawk's view of the frightening air pollution which is devastating Hong Kong. They made no secret of their alarm; the day they went for their aerial sight-seeing ride was Brown Tuesday, when a combination of dust and diesel turned our atmosphere into a lethal soup. I am delighted the people chosen to advise Mr Tung on our future saw Hong Kong at its worst. Hopefully, when they return later this year to discuss our problems, pollution will be written in large script at the top of the agenda. We are now reaching a true environmental crisis, an alarming state of affairs in which our shocking air is taken for granted by those forced to breathe it. Warnings of high pollution levels are shrugged off as inevitable. People elsewhere do not accept breathing poison. Last week I was in Australia, where newspapers published large photographs of Hong Kongers hurrying through murky streets clutching masks over their noses and mouths. Coming home from Singapore, I glanced through a leading international news magazine; the familiar skyline of Central loomed in a gloomy pall of smoke, illuminated by a sickly orange sun sinking into a filthy dusk. 'Do you live there?' the lady next to me asked, with pity. Do not be in any doubt that the world is becoming well aware of our environmental collapse. On TV, in the press and by word of mouth, people everywhere are being informed constantly that Hong Kong is under ecological threat. The warning by a local academic that in 15 years time the city would be unliveable received enormous publicity abroad. The rush of people to hospital with illnesses which may or may not be linked to the air creates headlines which do not attract visitors. Yet what can the tourist industry do to counter such harmful publicity? Every frightening word is true, every image a mirror of unhappy reality. A leading eye-surgeon tells me that one-third of all his cases are caused by particulates in the air blocking tear ducts which then become infected. A hospital superintendent tells me that many respiratory problems are either caused or made worse by breathing our air. Of all our civic leaders, politicians and civil servants, only Legislative Councillor Christine Loh Kung-wai has had the courage to face up to the unpleasant facts and to demand action. Alas, this woman with a true set of values - what's the use being rich and having the vote if you can't breathe? - is largely ignored. If our leaders are serious about taking action and not just talking about it, they must make some hard choices. Ms Loh suggested slamming smoky vehicles up to $5,000 for a first offence. What a good idea. She urged that all vehicles be forced to take an annual emission test. She wants taxis to switch to LPG fuel within three years and for mini-buses to switch to petrol or LPG. And why not turn large areas of Causeway Bay, Mongkok and Central into pedestrian areas? This would not only mean less pollution at street level but also be attractive to visitors. So tycoons will have to get out of their Rolls-Royces and walk a few metres. Good. It can be done; look at Cologne and a dozen other European cities. The Environmental Protection Agency monitors our air, using the latest techniques. But what use is this information by itself? The dismaying statistics should force the Government to ram through iron-fisted regulations combatting air pollution, not merely telling us what is killing 2,000 people a year. Much pollution could be eliminated swiftly if Mr Tung ordered the Commissioner of Police to apply ruthlessly and relentlessly laws which already exist. If traffic police stopped every single vehicle belching filthy fumes or black smoke and ordered them off the road until they had been effectively repaired, there would be a noticeable improvement. Another source of pollution is dust, much of it blown from construction sites across the Shenzhen River. What are we doing about this? We are going to talk about it with the Guangdong authorities. Talk? Where do they find the breath? The Environmental Protection Department is aware of the problems and knows there are solutions. But to bring about an improvement requires political backbone; where is it? Ultimately, we cannot blame the rest of the world if they choose to visit some cleaner, greener destination. We have nobody to blame but ourselves.