Incidence Rates of Malignant Diseases in Childhood and Adolescence in Children to Swedish Fishermen

Abstract

In this register-based study the risks of childhood malignant diseases in the offspring of Swedish fishermen were analysed. Having a fisherman as a parent was used as surrogate for exposure, both pre-and postnatal, to Persistent Organic Pollutants (POPs) due to high fish consumption. A cohort of fishermen was identified by Statistics Sweden by using the national census registration carried out from 1960 to 1990. For each fisherman, 4 matched -population-based referents were drawn. The children of fishermen and referents were identified and matched against the Swedish cancer registry 1960-1998, the causes of death registry 1960-1997 and notifications of deaths 1998-1999. Children diagnosed with cancer before the parent appeared in the census were excluded. MantelHaenszel analysis, adjusted for age and gender, was performed. Incidence rate ratios (IRR) and 95% Confidence Intervals (CI) for the different malignant diagnoses in children 0 to 19 years old were calculated. Fishermen children had an overall increased incidence rate ratio of cancer, IRR=1.38, 95% CI=0.96-2.00. An increased incidence rate ratio was observed for acute lymphatic leukaemia (ALL), IRR=2.65, 95% CI=1.005-6.97, and in west coast children for non-Hodgkin's lymphoma, IRR=3.19, 95% CI=0.98-10.4. The importance of exposure to POPs to these findings needs further investigation.