Wastewater treatment and public health in Nunavut: a microbial risk assessment framework for the Canadian Arctic

Abstract

Wastewater management in Canadian Arctic communities is influenced by several geographical factors including climate, remoteness, population size, and local food-harvesting practices. Most communities use trucked collection services and basic treatment systems, which are capable of only low-level pathogen removal. These systems are typically reliant solely on natural environmental processes for treatment and make use of existing lagoons, wetlands, and bays. They are operated in a manner such that partially treated wastewater still containing potentially hazardous microorganisms is released into the terrestrial and aquatic environment at random times. Northern communities rely heavily on their local surroundings as a source of food, drinking water, and recreation, thus creating the possibility of human exposure to wastewater effluent. Human exposure to microbial hazards present in municipal wastewater can lead to acute gastrointestinal illness or more severe disease. Although estimating the actual disease burdens associated with wastewater exposures in Arctic communities is challenging, waterborne- and sanitation-related illness is believed to be comparatively higher than in other parts of Canada. This review offers a conceptual framework and evaluation of current knowledge to enable the first microbial risk assessment of exposure scenarios associated with food-harvesting and recreational activities in Arctic communities, where simplified wastewater systems are being operated.

Disinfection and removal of human pathogenic bacteria in arctic waste stabilization ponds

“…The presence of pathogens in the effluent may pose a risk to human health through various exposure pathways but this will obviously depend on the number and survival of the pathogens being released into the arctic environment and the human and wild-life interactions with 553 impacted areas (Harper et al 2011, Daley et al 2017. The predicted infectious dose for pathogenic enterohemorrhagic E. coli serotypes such as O157:H7 is only 10 to 100 bacteria 555 (Theron and Cloete 2002), while for L. monocytogenes it is 10 7 -10 8 CFU in healthy hosts and 556 10 5 -10 7 CFU in susceptible individuals (Farber et al 1996).…”

“…People living in Nunavut communities may particularly be at risk as their diets are reliant on the local harvest of food from traditional sources (Daley et al 2014). In addition, recreational activities often take place near wastewater effluent discharging areas (Harper et al 2011, Daley et al 2017. Finally, the overcrowded housing in these communities may be exacerbating the frequency of inter-person spread of infectious agents (Goldfarb et al 2013, Harper et al 2011.…”

Antibiotic resistance genes in municipal wastewater treatment systems and receiving waters in Arctic Canada

“…The issue of antibiotic resistance is of particular importance in the Canadian Territory of Nunavut, which is primarily inhabited by Inuit who practice a number of food harvesting activities (hunting, fishing, shellfish harvesting, etc.) that may create exposure pathways with wastewater constituents including ARBs (Daley et al, 2015(Daley et al, , 2017.…”

Wastewater Treatment in Remote Arctic Settlements

“…The temperature of water in the septic tank was 2-4 degrees Celsius in the cold season. This is one of the main reasons for unsatisfactory biological wastewater treatment [2,6,8,9,32].…”

“…The tendency of unsatisfactory performance of biological treatment can be found not only in the territory of the Russian Federation but also in the territory of foreign countries, such as Greenland [5], the Canadian Arctic [6,7], the state of Alaska (USA) [8], Northern Norway, Finland, and others. Research revealed that the concentration of pollutants in the conditions of a decentralized wastewater disposal system was two to three times higher in the obtained water compared with in samples from a centralized sewage in other regions [9].…”