Risk of childhood acute lymphoblastic leukaemia following parental occupational exposure to extremely low frequency electromagnetic fields.

BACKGROUND: Earlier studies have reported moderate increases in the risk of acute lymphoblastic leukaemia (ALL) among children whose mothers have been occupationally exposed to extremely low frequency (ELF) electromagnetic fields. Other studies examining parental occupational exposure to ELF and ALL have reported mixed results. METHODS: In an Australian case-control study of ALL in children aged < 15 years, parents were asked about tasks they undertook in each job. Exposure variables were created for any occupational exposure before the birth of the child, in jobs 2 years before birth, in jobs 1 year before birth and up to 1 year after birth. RESULTS: In all, 379 case and 854 control mothers and 328 case and 748 control fathers completed an occupational history. Exposure to ELF in all time periods was similar in case and control mothers. There was no difference in exposure between case and control fathers. There was no association between maternal (odds ratio (OR)=0.96; 95% CI=0.74-1.25) or paternal (OR=0.78; 95% CI=0.56-1.09) exposure to ELF any time before the birth and risk of childhood ALL. CONCLUSION: We did not find an increased risk of ALL in offspring of parents with occupational exposure to ELF.

Barriers to immunisation in general practice.

OBJECTIVE: To identify barriers to immunisation in general practice. METHOD: The study was conducted in Perth, Western Australia, as a cross-sectional postal survey between November 1996 and January 1997. Questionnaires were sent to all known GPs in three of the seven metropolitan Divisions of General Practice, of whom 301 (72%) responded. RESULTS: When a child presented with a minor illness and there were no contraindications to immunisation, 62% of GPs said they would always or frequently offer immunisation. Immunisation would be withheld incorrectly because of an upper respiratory tract infection by 43% of GPs and because of antibiotics by 50%. Combined diphtheria-tetanus vaccine (CDT) would be substituted incorrectly for diphtheria-tetanus-pertussis vaccine (DTP) by 41% if there was an unexplained temperature of 38 degrees C following a previous dose of DTP. While more than half (56%) reported that vaccines were correctly stored, only 26% reported that the refrigerator temperature was checked daily. Eighty per cent reported that they completed an Australian Childhood Immunisation Register notification form. CONCLUSIONS: GPs require ongoing education about contra-indications to immunisation and when substitution of CDT for DTP is required. There is room for increased opportunistic immunisation and encouragement to notify the Australian Childhood Immunisation Register when they immunise a child. IMPLICATIONS: A major challenge is to find an innovative approach that would encourage and enable GPs to assess immunisation status and offer immunisation where appropriate at every clinical encounter.