To those pro and anti-smoking lobbyists who had hoped for rioting in the shopping malls and departure lounges of the world's airports, l July 1996 was a remarkably uneventful day. As the deadline set by the International Civil Aviation Organisation (ICAO) for achieving a worldwide smoking ban on all international passenger flights it was probably more an occasion to measure progress in the eradication of a complex social habit than in tossing brickbats at the tobacco industry.

Although airlines and governments are still some way from achieving ICAO's goal, enormous progress has been made on both the international and domestic fronts. Like most transport systems, however, balancing the rights of smokers and non-smokers is a complicated and emotive business, but damage to the health of passive smokers (non-smokers forced to inhale tobacco fumes generated by smokers) and legal settlements recognising this hazard have added some urgency to the way airlines are addressing the issue.

As a follow-up to ICAO's landmark Resolution A29-15 of 1992 calling for a smoke-free travel environment on all international flights, therefore, the international body recently disclosed details of a progress report on how close the industry is to achieving the 1 July 1996 goal. As part of this exercise ICAO sent missions to five global regions including visits to seven civil aviation authorities, seven major airlines, four national safety agencies, two major aircraft manufacturers and three other international bodies.

Of the 67 responding states, 46 indicated that some type of smoking ban was in effect, 19 that there was no ban and one which wouldn't say. Fifteen bans applied to commercial international flights and 37 to domestic flights. According to the finding, the ban applied to flights of specific duration in 15 states and in 20 others to particular routes. Seven other types of prohibition - for example, on charter airlines - were also reported. And of the smoking bans in effect, 23 applied to cockpits as well as cabins with another nine countries planning to extend bans to cockpits.

Other data reveal the extent to which curbs on in-flight smoking are being initiated by states a opposed to the individual carriers within their jurisdiction. "Of the 46 states reporting smoking back: in effect," says ICAO, "20 had state-imposed bans, 22 airline-imposed bans and four cases, information as to the type of ban was not given. " Elsewhere, 20 of the 67 respondents indicated state-imposed smoking bans in some part of airport terminals; and four other bans imposed by other authorities "either in addition to state requirements or in the absence of them".

Having trawled its 18l member governments, ICAO concluded in the somewhat prosaic language of international agencies that 'Resolution A29-15 is being implemented by way of smoking bans on domestic on international flights'. Clearly, though, the extent to which this is happening is being determined partly by health factors and partly by attitudes to smoking in different countries of the world.

Carriers based in Asia and most parts of the old Soviet Union, for example, still tolerate smoking to a far greater extent than those in North America and Northern Europe. So, too, do many foreign airlines operating to these destinations. While SAS may have abolished in-flight smoking in its own pristine backyard, therefore, it still allows it on services to Spain, Italy, Greece, Turkey 'as well as to certain countries in the eastern part of Europe' and on intercontinental flights.

As a pioneer in the field, Air Canada pursued a system-wide ban on all in-flight smoking for almost 20 years, finally achieving this objective in January 1991. Having done so a year before ICAO's anti-smoking resolution was enacted, its influence on the Montreal-based body in this matter was palpable. This occurred against a background of growing public opposition in Canada to the promotion and consumption of tobacco products and the passing of the bitterly contested Tobacco Products Control Act of 1989.

Like most airlines, Air Canada has walked a tricky commercial tightrope, balancing the likes and dislikes of its various customer groups but with the sentiments of its key domestic market uppermost. For carriers based in countries where public health issues are less tobacco-focused, a more gradualist approach is inevitable. As the craze for consumer goods in Asia and the CIS diminishes, say experts, there is no reason to believe that tobacco health hazards will not ultimately generate similar bans on smoking in these regions.

Although a long way behind Air Canada's 1991 cut-off point, British Airways is another airline - one of many - moving steadfastly towards becoming a zero smoking operation. To this end it recently added another 350 long-haul flights on which smoking is banned, moving one step closer to outlawing smoking on all of the 1,180 dally flights it currently operates. As a consequence, the London-based carrier now says it only provides smoker seats on 80 daily flights. In fact, this picture is not untypical of most major western carriers.

Apart from having to appease the pro-smoking lobby, of course, a worrying by-product of total prohibition to the airlines is how it might impinge on flight safety. Possible risks areas identified by ICAO include illicit smoking in cabin or lavatories; passenger misbehaviour caused or generated by withdrawal; deterioration of flight crew performance due to nicotine withdrawal; and conflicts between smoking and non-smoking flight crew members.

ICAO's recent soundings conclude that, although isolated incidents related to banning smoking on board aircraft have been reported, 'none of the administrations, organisations or airlines consulted considered that any of these incidents constituted a risk to flight safety'. Enforcing existing measures, it said, would minimise or eliminate any fire hazards caused by surreptitious smoking.

The World Health Organisation - which has played a pivotal role in changing global attitudes to smoking over the past 25 years - now believes a worldwide ban 'however long or short the flight' could still happen in the 1990 based on current trends. In its own way therefore, air transport, its agents and intermediaries - through a subtle process of persuasion and exclusion - continue to make a significant contribution to eradicating nicotine addition and a major source of human disease.