[A method to estimate one's own blood alcohol concentration when the ministerial tables are not avaible].

To reduce the prevalence of driving under the influence, tables allowing to estimate one's own blood alcohol concentration (BAC) by type and quantity of alcoholic drinks intake have been enacted by decree in Italy. Such tables, based on a modified Widmark's formula, are now put up in all public concerns serving alcoholic beverages. Aim of this initiative is to try to get subjects which consume alcoholics and then will drive a vehicle take in account their own estimated BAC and, on this base, put into effect, if needed, suitable actions (to avoid or to limit a further consumption, to wait more time before driving, to leave driving a sober subject). Nevertheless, many occasions exist in which these tables are not available. To allow anybody to rough estimate his own BAC in these cases too, a proper method has been developed. Briefly, the weight (in grams) of consumed alcohol has to be divided by half her own weight, if female drunk on an empty stomach (by the 90% of her own weight, if she drunk on a full stomach); by 70% of his own weight, if male drunk on an empty stomach (by 120% of his own weight, if he drunk in a full stomach). Consistency between BAC values estimated by the proposed method and those shown in the ministerial tables is very narrow: they differ in a few hundredth of grams/liter. Unlike the ministerial tables, the proposed method needs to compute the grams of ingested alcohol. This maybe involves some difficulties that, nevertheless, can be overcome easily. In our opinion, the skillfulness in computing the grams of assumed alcohol is of great significance since it provides the subject with a strong signal not only in road safety terms, but also in health terms. The ministerial tables and the proposed method should be part of teaching to issue the driving licence and to recovery of driving licence taken away points. In broad terms, the school should teach youngs to calculate alcohol quantities assumed by drink to acquaint them with the risks paving the way for a more aware drinking when they will come age.