Italian multicentricepidemiological case control strudy on risk factors for childhood leukemia,non hodgkin limphoma and neuroblastoma:study population and prevalence of risk factors in Italy

Abstract

Background Aetiology of childhood leukaemia and childhood neoplasm is poorly understood. Information on the prevalence of risk factors in the childhood population is limited. SETIL is a population based case/control study on childhood leukaemia, conducted with two companion studies on non-Hodgkin Lymphoma (NHL) and neuroblastoma. The study relies on questionnaire interviews and 50 Hz magnetic field (ELF-MF) indoor measurements. This paper discusses the SETIL study design and includes descriptive information. Methods The study was carried out in 14 Italian regions (78.3% of Italian population aged 0?10). It included leukaemia, NHL and neuroblastoma cases incident in 0?10 year olds in 1998-2001,registered by the Italian Association of Paediatric Haematology and Oncology (AIEOP)(accrual over 95% of estimated incidence). Two controls for each leukaemia case were randomly sampled from the Local Health Authorities rolls, matched by gender, birthdate and residence. The same controls were used in NHL and neuroblastoma studies. Parents were interviewed at home on: physical agents (ELF-MF and ionizing radiation), chemicals (smoking, solvents, traffic, insecticides), occupation, medical and personal history of children and parents, infectious diseases, immunizations and associated factors. Occupational exposure was collected using job specific modules. ELF-MF was measured in the main rooms (spot measurement) and close to child?s bed (48 hours measurement). Results The study included: 683 leukaemia cases (87% ALL, 13% AnLL), 97 NHL, 155 neuroblastomas, and 1044 controls.ELF-MF long term measurements were obtained for 61.1% of controls and 81.6% of leukaemia cases; 8.8% of controls were exposed at over 0.1 microTesla (μT), 3.5% and 2.1% at respectively over 0.2 and 0.3 μT. 25% of controls? fathers had smoked over 10 cigarettes/day during the year of conception, varying according to education and region. Maternal smoking was less common (71.4% did not smoke in pregnancy). Maternal passive smoking during pregnancy was reported by 31.2% of controls; the child?s passive smoking for 28.6%. Occupational exposure to solvents was estimated in 18.3% of controls? fathers and 7.7% of mothers. Contact with public was more frequent among mothers (36.1%) than fathers (23.4%). Conclusions SETIL represents a data source on exposure of Italian children to a broad array of potential carcinogenic factors.