title: Childhood leukemia and residential proximity to industrial and urban sites.
abstract: BACKGROUND
  Few risk factors for the childhood leukemia are well established. While a small fraction of cases of childhood leukemia might be partially attributable to some diseases or ionizing radiation exposure, the role of industrial and urban pollution also needs to be assessed.
  
  
  OBJECTIVE
  To ascertain the possible effect of residential proximity to both industrial and urban areas on childhood leukemia, taking into account industrial groups and toxic substances released.
  
  
  METHODS
  We conducted a population-based case-control study of childhood leukemia in Spain, covering 638 incident cases gathered from the Spanish Registry of Childhood Tumors and for those Autonomous Regions with 100% coverage (period 1990-2011), and 13,188 controls, individually matched by year of birth, sex, and autonomous region of residence. Distances were computed from the respective subject's residences to the 1068 industries and the 157 urban areas with ≥10,000 inhabitants, located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to industrial and urban pollution sources were calculated, with adjustment for matching variables.
  
  
  RESULTS
  Excess risk of childhood leukemia was observed for children living near (≤2.5 km) industries (OR=1.31; 95%CI=1.03-1.67) - particularly glass and mineral fibers (OR=2.42; 95%CI=1.49-3.92), surface treatment using organic solvents (OR=1.87; 95%CI=1.24-2.83), galvanization (OR=1.86; 95%CI=1.07-3.21), production and processing of metals (OR=1.69; 95%CI=1.22-2.34), and surface treatment of metals (OR=1.62; 95%CI=1.22-2.15) - , and urban areas (OR=1.36; 95%CI=1.02-1.80).
  
  
  CONCLUSIONS
  Our study furnishes some evidence that living in the proximity of industrial and urban sites may be a risk factor for childhood leukemia.
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain. Electronic address: jgarcia@isciii.es.
authors.forename: Javier
authors.initials: J
authors.lastname: García-Pérez
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain. Electronic address: glabente@isciii.es.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: López-Abente
authors.affiliation: CIBER Epidemiología y Salud Pública (CIBERESP), Spain; National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain. Electronic address: dgomez@externos.isciii.es.
authors.forename: Diana
authors.initials: D
authors.lastname: Gómez-Barroso
authors.affiliation: Rare Disease Research Institute (IIER), Carlos III Institute of Health, Madrid, Spain; Consortium for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain. Electronic address: amorales@isciii.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Morales-Piga
authors.affiliation: Spanish Registry of Childhood Tumors (RETI-SEHOP), University of Valencia, Valencia, Spain. Electronic address: elena.pardo@uv.es.
authors.forename: Elena Pardo
authors.initials: EP
authors.lastname: Romaguera
authors.affiliation: Public Health Division of Gipuzkoa, BIODonostia Research Institute, Department of Health of the Regional Government of the Basque Country, Donostia, Spain. Electronic address: ibontama@gmail.com.
authors.forename: Ibon
authors.initials: I
authors.lastname: Tamayo
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain. Electronic address: pfernandezn@isciii.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fernández-Navarro
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain. Electronic address: rramis@isciii.es.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Ramis
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007938:Leukemia / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D012111:Residence Characteristics; D013030:Spain / Q000453:epidemiology; D014504:Urban Health
keywords: Case–control study; Childhood leukemia; Industrial pollution; Residential proximity; Urban pollution