Environmental contaminants and human health in the Canadian Arctic.

The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme (AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10 years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canada's guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.

Stereotactic breast biopsy: a six-year surgical experience.

A retrospective review was done of all stereotactic breast biopsies performed at the Central Baptist Hospital Breast Center from February 1994 through December 1999. A total of 1,080 biopsies were performed in 1,026 patients, all by surgeons working independently. Masses were biopsied in 54% and calcifications in 40%. Eighteen percent of biopsies were malignant. The most common benign diagnosis was fibrocystic disease (72%), followed by fibroadenoma (19%), lymph node (2%), and papilloma (2%). The most common malignant diagnosis was invasive ductal carcinoma (40%) followed by ductal carcinoma in situ (32%) and mixed invasive and in situ ductal carcinoma (19%). A prebiopsy BI-RADS mammographic Category III was associated with a 2% incidence of malignancy; Category IV--17%; Category V--90%. Atypical ductal hyperplasia on stereotactic biopsy was upgraded to a malignant diagnosis after reexcision in 19% of the cases. The false-negative rate was 0.4% (sensitivity 99%) and the complication rate was 3%, mostly related to bleeding. Stereotactic biopsy is a safe and accurate technique for the minimally-invasive diagnosis of abnormal mammograms.