The impact of an industrial disaster has scarcely been studied in cardiology. On 21 September 2001 at 10.17 am, a chemical plant storing ammonium nitrate exploded in the urban area of Toulouse, France. The explosion induced an earthquake reaching 3.4 on the Richter scale; 30 people died, 3000 were injured, and 27 000 homes were destroyed. The explosion released a cloud of atmospheric pollutants essentially composed of nitrogenous compounds. During a period of 24 hours, the greatest concentrations of NO₂ measured by the two ambient stations of an air quality network located near the chemical plant varied from 20–95 μg/m³. Another urban station recorded once, at 10.30 am, a concentration of 388 μg/m³. The monitor measuring the release of specific chemicals (NH₃) was destroyed by the explosion. No other data were available except for the personal detector devices of the firemen working around the crater (a perimeter of 500 m).

Since 1985 the acute myocardial infarction (AMI) incidence has been systematically recorded in the population living in the explosion area.¹ We investigated the relation between this stressful event and the occurrence of acute coronary syndromes (ACS). The main objective was to test whether this industrial disaster has …