Positive Health Online

Abstract

REYES and COLLEAGUES, 1. a School of Public Health and Health Systems, University of Waterloo , Waterloo , Canada; 2. b Department of Kinesiology , University of Waterloo , Waterloo , Canada; 3. c Department of Biology , University of Waterloo, Waterloo , Canada; 4. d Toxicology Centre, University of Saskatchewan , Saskatoon , Saskatchewan , Canada; 5. e Dehcho Aboriginal Aquatic Resources and Ocean Management , Hay River, Northwest Territories , Canada studied associations between omega-3 fatty acids, selenium content and mercury levels in wild-harvested fish from the Northwest Territories, Canada.

Background

Methodology

To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada.

Results

Average HgT levels ranged from 0.057 mg/kg (cisco) to 0.551 mg/kg (northern pike), while average n-3 FA concentrations ranged from 101 mg/100 g (burbot) to 1,689 mg/100 g (lake trout). In contrast to HgT and n-3 FA, mean Se concentrations were relatively similar among species. Consequently, species such as lake whitefish, cisco, and longnose sucker displayed the highest nutrient levels relative to HgT content. Levels of HgT tended to increase with fish size, while Se and n-3 FA levels were typically not associated with fork length or fish weight. Interestingly, HgT concentration was occasionally inversely related to tissue nutrient content. Significant negative correlations were observed between Hg and n-3 FA for lake trout, northern pike, and walleye. There were also significant negative correlations between Hg and Se noted for lake whitefish, cisco, and northern pike. Samples with the highest nutritional content displayed, on occasion, lower levels of HgT.

Conclusion

This study provides valuable information for the design of probabilistic models capable of refining public health messaging related to minimizing Hg risks and maximizing nutrient levels in wild-harvested fish in the Canadian subarctic.

References

Reyes ES1, Aristizabal Henao JJ2, Kornobis KM3, Hanning RM1, Majowicz SE1, Liber K4, Stark KD2, Low G5, Swanson HK3, Laird BD1. Associations between omega-3 fatty acids, selenium content, and mercury levels in wild-harvested fish from the Dehcho Region, Northwest Territories, Canada. J Toxicol Environ Health A.80(1):18-31. 2017. doi: 10.1080/15287394.2016.1230916. Epub 2016 Dec 1.