The Lagrange Street story: the prevention of aromatics air pollution during the last nine years in a European city

Benzene, toluene and xylenes (BTX) air pollution is a very important topic for environmental health, due to the toxicity and/or mutagenetic or carcinogenetic properties of these aromatics and the commercialisation of the unleaded gasoline containing amount of BTX. We measured BTX in the air of Turin city, the capital of Piedmont region (north-western Italy), during 10 years, from 1989 to 1998. The sampling site selected was Lagrange Street (LS), an “urban canyon” placed in the centre of the city. The behaviour of BTX in LS was conditioned by some local and national legislative measures enforced during 1990s for the reduction of automotive traffic and BTX air pollution, respectively. Taking into account the existence of similar measures undertaken also in several cities in the developed countries, largely described but never discussed, the aim of this study was to verify in LS the preventive effects of these regulatory actions by means of a longitudinal survey extended over 10 years. Results obtained in Lagrange Street highlight seasonal trends, typical of this kind of pollutants, and an important reduction (from 42.6 to 15.9 ppbv) of aromatic hydrocarbons (sum of benzene, toluene and xylenes) in atmospheric air from 1990 to 1997. In particular, the annual level of benzene in air showed a mean from 9.2 ppbv in 1990 to 2.0 ppbv in 1997, almost half of the 3.1 ppbv imposed by law since 31 December 1998. In conclusion, the present findings induce a consistent optimism about the usefulness and the effectiveness of these types of regulatory actions enforced to reduce the human exposure to BTX, which could be extended also to other trafficated sites where the aromatics air pollution has to be reduced.