Cellule interrégionale d’épidémiologie (Cire) Ouest 20, rue d’Isly CS 84224 35042 Rennes cedex, Registre breton des cancers de l’enfant Observatoire régional de la Santé Bretagne Centre d’affaires Patton 8D, rue Franz Heller C.S. 70.625 35706 Rennes cedex 7, Pôle cancérologie-hématologie CHU Morvan Brest 2, avenue Foch 29609 Brest cedex
Context and objectives: To respond to population concerns about the health impact of the nuclear submarines based at Ile Longue, a study was conducted of variations in the incidence of childhood leukaemia around Brest harbour. Methods: The study analysed data from the Brittany child tumour registry. It divided Finistère into 3 areas (i) Finistère excluding Brest and its harbour, (ii) Brest harbour, but excluding the city of Brest, (iii) the city of Brest. The 1991-2005 period was studied as a continuous or categorical variable according to the size of the area. Age-standardised analyses were performed with both external and internal (either Brittany or Finistère) references. Results: An excess incidence of leukaemia was observed throughout Finistère, due to an excess in Brest in 2000-2002. The characteristics of the 2000-2005 Brest cases were not consistent with a link to parental occupational exposure in nuclear defence activities. Conclusion: Standard and complementary methodological approaches offered a comprehensive view of the epidemiological situation and provided convergent indications that leukaemia incidence peaked in Brest in 2000-2002. This peak did not seem to be associated with a persistent environmental cause, but follow-up should continue.