THE release of the United States Environmental Protection Agency's (EPA) report on the effects of Environmental Tobacco Smoke (ETS) confirms, once again, what respected scientists have been warning for some years, that ETS is a serious health hazard. In the US the report estimates that 3,000 deaths per year from lung cancer among non-smokers can be traced to this cause. Furthermore, the incidence of asthma and other respiratory illnesses in this group affects tens of thousands. As a consequence of these findings, a recommendation has been made that ETS be classified as a ''Class A'' carcinogen, one of a select group of toxic substances known to cause cancer. Given the serious nature of these findings from a widely respected government agency, it is to be hoped that the community will lend support to the Secretary of Health and Welfare, Mrs Elizabeth Wong, in her continuing attempts to provide a safer environment for non-smokers - principally by encouraging her to extend the existing ban on smoking on public transport, in cinemas and other places of entertainment to include all restaurants over a certain size. If a complete ban is not acceptable to the public then it should be a legal requirement for a substantial proportion of smoke-free tables to be provided on an increasing basis over time. The acceptability of these proposals should not be a contentious issue. Firstly, because the majority of people in Hongkong do not smoke and deserve to be adequately protected against the behaviour of those who do and second, because there is very littleevidence that smokers themselves do not appreciate being able to dine in similar comfort when the facility exists. In addition to the protections to be provided in restaurants and other places where people congregate in large numbers, employers should consider the implications of these findings for their own employees, in particular, they should be taking action to create smoke-free environments at work. Failure to do so substantially increases the possibility that employees could seek legal redress for any illness contracted as a consequence of exposure to ETS on the grounds that the employer did not exercise a proper duty of care in the presence of a known hazard - such cases have already been brought to court in other countries and will undoubtedly increase over time. Companies which show concern for the health of their employees and customers will be pleasantly surprised that this is not a difficult issue, as long as it is approached and negotiated in an informed and sensitive manner. Methods for doing this already exist and have recently been publicised in Hongkong by the Council on Smoking and Health. As far as the tobacco industry is concerned, the results of the EPA study are a serious setback in its attempts to persuade Hongkong people that ETS is a non-problem invented by ''single issue fanatics'' who rather enjoy to mind other people's business. Now, not only do we find that smoking harms the health of smokers but non-smokers are seriously affected too. Such results require the Tobacco Institute of Hongkong to elaborate on its earlier statements that its own views on ETS arise from the analysis of reliable data which stand up to scrutiny in the international arena. Clearly, the attention it has given to the matter so far is insufficient. Dr ALAN R. KING Director Action on Smoking or Health Limited