The role of environmental factors in search and rescue incidents in Nunavut, Canada

OBJECTIVES

Unintentional injury is a leading cause of morbidity and mortality in Nunavut, where the importance of land-based activities and reliance on semi-permanent trails create unique risk profiles. Climate change is believed to be exacerbating these risks, although no studies have quantitatively examined links between environmental conditions and injury and distress in the Canadian Arctic. We examine the correlation between environmental conditions and land-based search and rescue (SAR) incidents across Nunavut.

STUDY DESIGN

Case study.

METHODS

Case data were acquired from the Canadian National Search and Rescue Secretariat. Gasoline sales from across the territory are then used to model land-use and exposure. We compare weather and ice conditions during 202 SAR incidents to conditions during 755 non-SAR days (controls) between 2013 and 2014.

RESULTS

We show daily ambient temperature, ice concentration, ice thickness, and variation in types of ice to be correlated with SAR rates across the territory during the study period.

CONCLUSIONS

These conditions are projected to be affected by future climate change, which could increase demand for SAR and increase injury rates in the absence of targeted efforts aimed at prevention and treatment. This study provides health practitioners and public health communities with clearer understanding to prepare, respond to, and prevent injuries across the Arctic.

Microbiological oxidation of hydrogen sulphide in a biofilter

The microbial oxidation of hydrogen sulphide present in an air stream was performed using a laboratory-scale biofilter packed with dry wastewater sludge (BSE, boues de station d'épuration) from an urban wastewater treatment plant. This granular and heterogeneous material contains organic and mineral components which favour colonization by bacteria. Adsorption and absorption of hydrogen sulphide taking place on such a packing (moisture content 30–40%) were determined. Results obtained with abiotic pilot units, fed with air (superficial air flow rate, 16 m/h) containing a sulphide level as high as 3260 mg/m3, showed that chemical oxidation can occur. The presence of numerous bacteria such as Thiobacillus spp. (i.e., 108–109 CFU/g dry weight) in biotic pilot units favoured complete oxidation to sulphate. High initial bacterial numbers and a neutral pH improved the removal efficiency of the biofilter. A high sulphide concentration (>3000 mg/m3) had a negative effect on the removal efficiency. The leaching of the metals contained in the sludges was studied. Peat and BSE biofilters were compared.Key words: Thiobacillus spp., hydrogen sulphide, biofilter, deodorization, bioleaching.

Cross-linguistic pause and rate phenomena in adults and adolescents

Three groups of 40 Ss (German adolescents and American adults and adolescents) read two passages and retold them. In confirmation of O'Connell Kowal, and Hörmann (1969) for German adults, a number of pause and rate measures were significantly different for semantically ordinary or unusual passages. Comparisons among the four experiments manifested different patterns of pauses and rate across the two languages and age brackets.