EPA, ENVIRONMENTAL PROTECTION AGENCY; GREATER DE VALLEY PEDIATRIC TUMOR REGIST; HHS, DEPT OF HEALTH AND HUMAN SERVICES; IARC; INTERREGIONAL EPIDEMIOLOGY STUDY OF CHIL; INTL AGENCY FOR RESEARCH ON CANCER; SWEDISH CANCER REGISTRY; SWEDISH CHILD LEUKEMIA GROUP; SWEDISH MEDICAL BIRTH REGISTRY; UNIV OF NC; US CHILDRENS CANCER STUDY GROUP; WHO, WORLD HEALTH ORG