While air-borne atmospheric filth remains a significant problem in contemporary Hong Kong, a few attempts have been made to address the issue. For decades, though, the matter was largely ignored, or regarded as just part of the price to be paid for the city's rapid economic growth.

Hong Kong's clear winter skies were justifiably famous - but only at higher altitudes, and in less populated areas. The colony's magnificent cool-weather vistas of mountains, sea and sky, reflected in period photographs, tell only part of the story from the post-war tourism boom. In urban districts, the air quality was very different. Photographs from the 1940s and 50s show a thick pall of dingy fug hanging over much of the city.

Until cheap, locally manufactured kerosene became available in the late 40s, most households cooked on solid fuel - a mixture of dried grass and firewood, or charcoal. Both gave off significant amounts of smoke and fumes. But as smoky kerosene became more widely available in the early 50s, it generated pollution problems as well. Local kerosene production increased sharply after the United Nations imposed a trade embargo with China after the outbreak of the Korean war in 1950; and it was an open secret that much was smuggled - along with diesel fuel and other petroleum products - into the mainland through Macau.

Plastics were an economic mainstay from the 50s until the 70s, and extrusion factories proliferated in older areas such as San Po Kong and Aberdeen. Their noxious fumes were legendary and provided a convenient cover for another very smelly enterprise that frequently took place alongside the manufacturing of plastic flowers and cheap toys: the refining of heroin from its smuggled morphine base. It is no coincidence that back in the days when the Hong Kong police and customs officials were the best that money could buy, factories located near Kai Tak airport, and the Aberdeen harbour, could refine and re-export imported "product" in quick time.

In tandem with the post-war economic boom, more ships used the port. At this time, many were still coal-burning; and oil-burning vessels used heavily polluting bunker fuel, as did the numerous cross-harbour passenger and vehicular ferries in the days before the cross-harbour tunnels. The main harbour area also had two coal-burning power stations, China Light and Power's station at Hung Hom, and the Hong Kong Electric plant at North Point. As Hong Kong's population expanded dramatically throughout the 50s, from a post-war average of a million to almost three million by the end of the decade, power generation - and the use of cheap, heavily polluting coal - also increased.

Over the same period, local road-side air quality continued to decline. As private affluence increased, so did the number of private cars. Many used diesel fuel - it was cheaper than petrol - and the sight of badly tuned Mercedes-Benz taxis belching noxious black vapour trails in their wake was a commonplace 60s sight that contemporary seekers of period nostalgia conveniently forget.

Better emission controls from the late 80s, mandatory low-sulphur fuels and the introduction of LPG taxis and mini-buses did much to improve road-side air quality. Powerful opposition from vested interests in the transport sector's functional constituency - yet another symptom of Hong Kong's ongoing political dysfunction - continues to stymie progress towards better roadside air quality. Nonetheless, it is worth recalling that the "good old days" were not quite as good as they are sometimes remembered.