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

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Abstract and Figures

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.
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Wastewater treatment and public health in Nunavut: a microbial
risk assessment framework for the Canadian Arctic
Kiley Daley
&Rob Jamieson
&Daniel Rainham
&Lisbeth Truelstrup Hansen
Received: 4 September 2016 /Accepted: 2 February 2017 /Published online: 21 February 2017
#Springer-Verlag Berlin Heidelberg 2017
Abstract Wastewater management in Canadian Arctic com-
munities is influenced by several geographical factors includ-
ing climate, remoteness, population size, and local food-
harvestingpractices. 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 operatedin a mannersuch thatpartially treated wastewater
still containing potentially hazardous microorganisms is re-
leased into the terrestrial and aquatic environment at random
times. Northern communities rely heavily on their local sur-
roundings 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 mu-
nicipal wastewater can lead to acute gastrointestinal illness or
more severe disease. Although estimating the actual disease
burdens associated with wastewater exposures in Arctic com-
munities is challenging, waterborne- and sanitation-related ill-
ness 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.
Keywords Conceptual model .Environmental exposures .
Indigenous health .Inuit .Quantitative microbial risk
assessment (QMRA) .Rural health .Water, Sanitation, and
Hygiene (WASH) .Wastewater
Communities in the Canadian Arctic territory of Nunavut face
unique wastewater treatment challenges due to climate, re-
moteness, small populations, and local food-harvesting prac-
tices (Bjerregaard et al. 2008; Johnson et al. 2014; Lam and
Livingston 2011;Martinetal.2007). The territory has a total
population of 34,000 spread across 25 remote communities,
varying in population from 150 to 7000 (Nunavut Bureau of
Statistics 2014). No roads connect the 25 isolated communi-
ties to one another or to other communities in Southern
Canada. Thus, each community requires its own municipal
public work infrastructure including wastewater treatment fa-
cilities. All but three have trucked drinking water distribution
and wastewater collection services, as opposed to piped con-
veyance or individual on-site systems. Communities use basic
wastewater treatment systems that are capable of only low
levels of pathogen removal (Huang et al. 2014). These sys-
tems typically rely exclusively on natural environmental pro-
cesses for treatment, making use of existing lagoons, wet-
lands, and ocean bays. They are operated in a manner such
that effluentpartially treated wastewater still containing po-
tentially hazardous microorganismsis released into the ter-
restrial and aquatic environment at random times.
Responsible editor: Gerald Thouand
*Kiley Daley
Centre for Water Resources Studies, Dalhousie University,
Halifax, NS, Canada
Department of Process Engineering and Applied Science, Dalhousie
University, Halifax, NS, Canada
Environmental Science Program, Dalhousie University, Halifax, NS,
National Food Institute, Technical University of Denmark, Kongens
Lyngby, Denmark
Environ Sci Pollut Res (2018) 25:3286032872
DOI 10.1007/s11356-017-8566-8
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... 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]. ...
... 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]. ...
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... Although extremely important, the effects of wastewater on the environmental resistome are still poorly studied in the Arctic. In the many Arctic regions, the human settlements deliver to the ecosystems wastewater containing various pollutants (Gunnarsdóttir et al., 2013;Daley et al., 2018) which could potentially mix with genetic material released from glaciers (Sajjad et al., 2020), forming a new combination of threats. Thus, the interplay between glaciers and wastewater to the spread of antibiotic resistance in the Arctic is of global importance in the identification of unknown and unexplored determinants of antibiotic resistance. ...
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The Arctic is one of the regions most affected by global climate change, and is subjected to changes linked with a melting cryosphere and increasing anthropopressure. Although antibiotic resistance is a global problem, the diversity and spread of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs) and integrons in the Arctic are strongly understudied. Therefore, the main aims of this study are the (1) determination of the type and frequency of integron-integrase genes and characterization of incorporated gene cassettes in the genomes of culturable bacteria and (2) quantitative analysis of class 1 integron-integrase gene and human mitochondrial DNA (Hmt-DNA) in the metagenome as markers of anthropogenic impact on the high Arctic environments of the Svalbard Archipelago. Samples of ice, water and sediments were collected in the most populated area of Sval-bard, Longyearbyen and its vicinity. Sampling was conducted along an environmental gradient with varying levels of human activity. The environmental gradient started from glaciers, following the proglacial river, the seashore, and the fjord bottom water, including untreated wastewater outflow to the sea. Class 1 integrons were detected in ARB isolated from glacial environments, freshwater and seawater, including wastewater outflow. Moreover, in the variable regions of integrons, genes determining different functions, including antibiotic resistance, virulence and physiological traits were found. These genes play crucial roles in the adaptation of bacteria to cold and dynamic environments. The relative abundance of intI1 genes were reported in metagenomes with different relationships to human activity (ice cores vs wastewater outflow), with the highest mean values observed in the wastewater outflow, and was positively correlated with abundance of the Hmt gene, revealing both natural and human roles in shaping the polar aquatic resistome.
... The model builds upon a conceptual framework (Daley et al., 2018a) and an initial screening-level, point-estimate assessment of risk in case study sites (Daley et al., 2019). Specifically, an inferential QMRA model rather than community-specificwas designed to reflect hypothetical Arctic wastewater treatment systems, receiving environment conditions, and exposure pathways. ...
Populations in Arctic Canada are strongly connected to, and draw sustenance from, the physical environment. Recreation and food harvesting locations, however, may be impacted by the basic wastewater treatment and disposal processes used in the region. Within these mixed socio-ecological systems, people may unknowingly be exposed to wastewater pathogens, either by direct contact or indirectly through activities resulting in exposure to contaminated locally harvested food. The objectives of this research are to estimate microbial health risks attributable to wastewater effluent exposure in Arctic Canada and evaluate potential mitigation options. A participatory quantitative microbial risk assessment (QMRA) approach was used. Specifically, community knowledge and information describing human activity patterns in wastewater-impacted environments was used with microbial water quality data to model a range of exposure scenarios and risk mitigation options. In several exposure scenario results, estimated individual annual risk of acute gastrointestinal illness exceeds a proposed tolerable target of 10⁻³. These scenarios include shore recreation and consumption of shellfish harvested near primary mechanical treatment plants at low tide, as well as travel in wetland portions of passive treatment sites during spring freshet. These results suggest that wastewater effluent exposures may be contributing to gastrointestinal illness in some Arctic communities. Mitigation strategies, including improved treatment and interventions aimed at deterring access to disposal areas reduce risk estimates across scenarios to varying degrees. Overall, well-designed passive systems appear to be the most effective wastewater treatment option for Arctic Canada in terms of limiting and managing associated microbial health risks. This research demonstrates a novel application of QMRA and provides science-based evidence to support public health, water, and sanitation decisions and investment in Arctic regions.
... Throughout the Arctic, gastrointestinal health is not only impacted by access to clean drinking water, but also to safe wastewater disposal. Due to climate, population size, and remoteness, many Arctic communities use basic treatment systems for wastewater management [59]. Treatment systems involve the natural environment and typically occur in lagoons, wetlands, lakes, and ponds. ...
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The Canadian Arctic has a long history with diarrheal disease, including outbreaks of campylobacteriosis, giardiasis, and salmonellosis. Due to climate change, the Canadian Arctic is experiencing rapid environmental transformation, which not only threatens the livelihood of local Indigenous Peoples, but also supports the spread, frequency, and intensity of enteric pathogen outbreaks. Advances in diagnostic testing and detection have brought to attention the current burden of disease due to Cryptosporidium, Campylobacter, and Helicobacter pylori. As climate change is known to influence pathogen transmission (e.g., food and water), Arctic communities need support in developing prevention and surveillance strategies that are culturally appropriate. This review aims to provide an overview of how climate change is currently and is expected to impact enteric pathogens in the Canadian Arctic.
... Greywater in lower income areas, such as the study communities described here, has been shown to be more concentrated because of low water use (Katukiza et al., 2015), and when this greywater is disposed on the ground it has been shown to contaminate areas with fecal coliforms (Casanova et al., 2001b). Direct contact with greywater during disposal or subsequently through activities near the disposal site, such as through boot or vehicle tire contamination (as shown with fecal matter in Chambers et al., 2009) or subsistence activities (Daley et al., 2018), has been characterized as a significant risk for health (Ottoson and Stenström, 2003;Benami et al., 2016). Furthermore, greywater pathogens can become airborne attached to dust or air particles, resulting in additional exposure pathways. ...
Conference Paper
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... To cope with insufficient water access to their homes, households depend on local water sources that are culturally significant, such as rivers, ice, snowmelt and lakes (Harper et al. 2015;Wright et al. 2018). These water resources can adversely impact health due to poor water quality or contamination in some instances (Daley et al. 2018;Harper et al. 2015;Martin et al. 2007). ...
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... summary of articles about climate change, water, and health in the Circumpolar North by depth of climate change consideration, extent of climate-health association, and consideration of future climate change impacts[39,44,45]. ...
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... Rural populations obtain water from drinking water sources where the water quality is often unknown, with potential contamination due to runoff, improper wastewater treatment, and other anthropogenic activities. In many rural communities, natural areas that are being used for passive wastewater treatment may simultaneously serve as a community's drinking water source as well as be used for recreation or food harvesting (Daley et al., 2018). Unreasonable design and poor management of onsite sanitation systems also negatively impact the security and hygiene of rural drinking water wells (Otaki et al., 2021). ...
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We estimated the disease burden from water, sanitation, and hygiene at the global level taking into account various disease outcomes, principally diarrheal diseases. The disability-adjusted life year (DALY) combines the burden from death and disability in a single index and permits the comparison of the burden from water, sanitation, and hygiene with the burden from other risk factors or diseases. We divided the world's population into typical exposure scenarios for 14 geographical regions. We then matched these scenarios with relative risk information obtained mainly from intervention studies. We estimated the disease burden from water, sanitation, and hygiene to be 4.0% of all deaths and 5.7% of the total disease burden (in DALYs) occurring worldwide, taking into account diarrheal diseases, schistosomiasis, trachoma, ascariasis, trichuriasis, and hookworm disease. Because we based these estimates mainly on intervention studies, this burden is largely preventable. Other water- and sanitation-related diseases remain to be evaluated. This preliminary estimation of the global disease burden caused by water, sanitation, and hygiene provides a basic model that could be further refined for national or regional assessments. This significant and avoidable burden suggests that it should be a priority for public health policy.
It is shown that salmonellae can be isolated from bottom sediments with far greater frequency than directly from the overlying water. Within the limits of existing methodology, quantitation of salmonellae in mud is also possible. There is approximately a 100 to 1000- fold increase in fecal coliform bacteria in the mud as compared to the overlying water. Salmonellae were isolated from 19% of the mud samples when the fecal coliform density in the overlying water was between p and 200/100 ml; from 50% between 201 and 2000; and from 80% over 2000.
The Arctic regions are inhabited by diverse populations, both indigenous and non-indigenous. Health Transitions in Arctic Populations describes and explains changing health patterns in these areas, how particular patterns came about, and what can be done to improve the health of Arctic peoples. This study correlates changes in health status with major environmental, social, economic, and political changes in the Arctic. T. Kue Young and Peter Bjerregaard seek commonalities in the experiences of different peoples while recognizing their considerable diversity. They focus on five Arctic regions ? Greenland, Northern Canada, Alaska, Arctic Russia, and Northern Fennoscandia, offering a general overview of the geography, history, economy, population characteristics, health status, and health services of each. The discussion moves on to specific indigenous populations (Inuit, Dene, and Sami), major health determinants and outcomes, and, finally, an integrative examination of what can be done to improve the health of circumpolar peoples. Health Transitions in Arctic Populations offers both an examination of key health issues in the north and a vision for the future of Arctic inhabitants.
A majority of communities in the Canadian territory of Nunavut rely on passive waste stabilization ponds (WSPs) for domestic wastewater treatment. Little research has been conducted on the treatment performance of these systems. Therefore, in response to impending federal wastewater regulations, a research program was conducted in order to characterize contaminant removal, with phosphorus a contaminant of particular concern. The performance of WSPs in the Arctic communities of Kugaaruk, Pond Inlet, Grise Fiord, and Clyde River was evaluated from 2011 to 2014. Removal of total phosphorus was highly variable, ranging from 24% (Pond Inlet, 2014) to 76% (Grise Fiord, 2011). The average removal efficiency was 44%. Effluent total phosphorus concentrations generally exceeded 7 mg P/L, partly due to elevated raw wastewater concentrations. Over the course of the treatment season (defined as June to September, when the WSP is thawed), limited additional total phosphorus removal was observed. A fractionation analysi...
Hazard Analysis and Critical Control Points (HACCP) was applied for identifying and controlling exposure to pathogenic microorganisms encountered during normal sludge and wastewater handling at a 12,500 m(3)/d treatment plant utilising tertiary wastewater treatment and mesophilic sludge digestion. The hazardous scenarios considered were human exposure during treatment, handling, soil application and crop consumption, and exposure via water at the wetland-area and recreational swimming. A quantitative microbial risk assessment (QMRA), including rotavirus, adenovirus, haemorrhagic E coli, Salmonella, Giardia and Cryptosporidium, was performed in order to prioritise pathogen hazards for control purposes. Human exposures were treated as individual risks but also related to the endemic situation in the general population. The highest individual health risk from a single exposure was via aerosols for workers at the belt press for sludge dewatering (virus infection risk = 1). The largest impact on the community would arise if children ingested sludge at the unprotected storage site, although in the worst-case situation the largest number of infections would arise through vegetables fertilised with sludge and eaten raw (not allowed in Sweden). Acceptable risk for various hazardous scenarios, treatment and/or reuse strategies could be tested in the model.
This chapter provides a basic review of deterministic and empirical statistical modeling and their application for predicting microbiological surface water quality. The key to deterministic model development is the conceptualization of the various processes affecting fate and transport of fecal bacteria in the environment. Several different types of deterministic models have been applied to fecal bacteria in surface waters. A simplified conceptual model for fecal bacteria in surface water is presented. The chapter describes various processes that affect the fate and transport of fecal indicator bacteria (FIB) in surface waters and provide examples of their mathematical parameterization. The movement of bacteria from one water parcel to another occurs because of advection, diffusion, and dispersion. Advection is the movement of bacteria with water. In surface waters, velocities must be measured using flow meters to gain insight into the importance of advection. Kinetic models have been used extensively to model particle aggregation in surface waters, but have not yet been applied to the study of fecal bacteria-particle interactions in surface waters. There are four steps in the development of a statistical model. First, appropriate predictors must be selected to be used as independent variables in the model. Second, the statistical method must be chosen (e.g., multiple linear regression, partial least squares regression, random forests). Third, the model must be trained, or developed. Finally, the model must be validated using an independent data set.