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.
The significance of cord blood neutropenia as a screening tool for early-onset sepsis (EOS) is unclear. The objectives were to define reference values for cord blood neutrophil count and to determine ...the sensitivity and positive likelihood ratio of cord neutropenia for the detection of EOS.
This retrospective observational cohort study included all mother-infant pairs with deliveries between 2009 and 2014 for whom cord neutrophil counts were routinely done. EOS cases were identified by interrogation of electronic charts. Maternal and perinatal factors were assessed to determine reference values of cord neutrophil. The diagnostic value of neutropenia for detecting EOS was assessed. A nested case-control design was used to measure the value of neutropenia in the detection of EOS in comparison with other risk factors.
A total of 8,590 mother-infant pairs were included. We identified 84 sepsis cases. The neutrophil count was strongly associated with gestational age. Neutropenia adjusted for gestational age was strongly associated with EOS and had good specificity but poor sensitivity. The addition of neutropenia to other EOS risk factors increased sensitivity without decreasing specificity.
Cord blood neutropenia was significantly associated with EOS and the addition of cord neutropenia to current EOS risk factors increased the detection rate of EOS.
The Medipix device is a silicon pixelated detector designed by CERN for the detection of different types of radiation. The detector response features can be exploited to identify different types of ...particles: heavy charged particles, mips, electrons or photons. However, while heavily ionizing charged particles are clearly recognizable, electrons and photons can hardly be distinguished from each other and thus, mistagging of radiation quanta has to be considered. Experiments were performed to quantify the mistag rate in different experimental situations. A GEANT4 simulation of the detector and the experimental setup was used to further understand the results. The detection efficiency for photons was studied and the advantages of using a Timepix device highlighted.
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