Re Results from N7: Assess and predict food and drinking water safety 9/11/19 Presented By: Brian Laird, University of Waterloo Kelly Skinner, University of Waterloo Pieter Aukes, University of Waterloo
Traditional Food Consumption Notices in the NWT: Mercury and Cadmium • Elevated levels of contaminants sometimes seen in traditional foods • Cd: up to 94 mg/kg ww in moose’s kidney (Larter et al., 2018) • Hg: to 3.1 μg/g ww (Laird et al., 2018) • GNWT responsible for issuing consumption notices when contaminant levels may pose health risks • Moose: organ specific, location specific • Fish: species, lake, length specific + group at risk PAGE 2
“ But what do these results mean for our health? ” § Contaminant biomonitoring to better answer that question. § Consultation process of up to 18 months before the implementation. § Design according to the local concerns (sampling, types of contaminants, working with co-located researchers, etc.) Communication & Consultation Sample Collection Questionnaires Chemical Analysis Follow Up PAGE 3
By the numbers…. Levels ♠ , Determinants ♣ , and Sources ♦ : +300 person-days in the field ♠ ♣ ♦ : Mercury; PAHs ; Cadmium 537 participants ♠ ♣ Lead, 917 samples collected: 443 hair, 276 ♠ Manganese, Arsenic; Many More blood, 198 urine Select Findings So Far: 523 questionnaires completed: 237 • Although fish mercury levels are FFQ, 199 24h recall, 87 risk perception sometimes elevated, overall exposures to 111 biomarkers: 23 metals, 49 POPs, mercury have remained low. • Cadmium and PAH exposures more cotinine, 19 PAHs, 13 phthalates, 5 strongly linked with smoking than food arsenic species, 2 n-3 PUFA consumption PAGE 4
Biomonitoring: Lead • Average levels appeared similar-to-higher than reported in the CHMS or FNBI. • < 2% of participants had BLL over health based guidance values (e.g., 100 μg/L for the general population; 50 μg/L for susceptible subpopulations). • Significant regional differences in Pb biomarkers. Lead Mackenzie Valley CHMS(2) FNBI 2016-2018 2009-2011 2010-2012 95 th 95 th 95 th DR (%) GM GM GM centile centile centile Blood (μg/L) 100 16 70 13 32 12 33 (n=276) Urine (μg/L) 99. 0.59 4.0 0.52 1.9 0.51 2.3 (n=198) (μg/g 0.69 3.8 0.48 1.6 0.56 2.2 creat.) PAGE 5
Health Health and and Ris isk Communic unicatio tion n in in th the e Sa Sahtú an and De Dehch cho re regions Health 3 Stakeholder Community Terminology Interviews Interviews Messages (n=12) Workshops (n=7) Survey (n=87) 1 community 2 communities Yellowknife 6 communities
Health Messages Survey Co Country F y Foods Co Consumption P Patterns a and Pr Preferences • 99% reported consuming country foods • 38% overall preferred to eat only country foods rather than store- bought or a mix of both • 45% Females; 29% males • 49% Sahtú; 27% Dehcho
Health Messages Survey Awareness of Co Consumption Notices Overall Male Female Dehcho Sahtú (%) (%) (%) (%) (%) Consumption Notices/Advisories (n=87) Have you heard any advisories or 66 73 68 72 70 messages about fish that had high levels of mercury ? Have you heard any advisories or 26 16 25 21 21 messages about moose with high levels of cadmium ?
Health Messages Survey Sources of Co Consumption Notices/Advisories Overall Fish and Mercury Advisories – Where or Male Female Dehcho Sahtú who did you hear that from? (n=35) (%) (%) (%) (%) (%) 52 50 53 48 51 a Researcher or Scientist 44 47 43 48 48 the Radio 44 47 53 39 46 Friends
Health Messages Survey Behavioural Ch Changes from Co Consumption Notices Overall Male Female Dehcho Sahtú Since hearing the messages about fish and mercury (n=59)*: (%) (%) (%) (%) (%) 46 42 43 45 42 I am more concerned about the fish I eat 34 32 35 37 31 In general, I have decreased the amount of fish I eat 24 I have reduced my consumption of only some kinds of fish 29 21 32 17 (e.g. whitefish, trout) that I eat 20** 29 15 21 21 I have changed the location where I usually fish 21 12 21 10 15 I eat smaller fish 8 I eat less predatory fish (examples of predatory fish are 13 6 15 3 walleye, lake trout or northern pike) *Results are reported for those who chose Strongly Agree or Agree. **Statistically significant association with lower mercury concentration in hair (p=0.03)
Dis Dissolv lved O Organ anic M ic Matter & & Dr Drin inkin ing W Water Dissolved Organic Matter (DOM) • Heterogeneous mixture of organic molecules • Comprised mainly of C • Influences aquatic health & drinking water quality • Freshwater concentrations increasing in Northern hemisphere Disinfection By-Products (DBP) • Chlorine added as disinfectant • Amount needed generally based on [DOM] • More DOM ~ more chlorine needed • Reacts with organic matter to form harmful disinfection by-products (DBP) • Reactivity à DOM amount and composition
Dis Dissolv lved O Organ anic ic Ma Matter ( r (DOM) M) in in th the e NWT Wide range in the amount of DOM • Large differences in concentration across small spatial scale • i.e: Yellowknife (YK) subsurface vs YK lake Not all DOM is the same • High [DOM] with large components found from YK subsurface • Creeks and rivers contain lower concentrations of small DOM components
Dr Drin inkin ing W Water T Treatment & & DO DOM Differences in the ratio • Relationship with overall amount of DOM is not linear • Other factors must control chlorine consumption Need to better predict this to effectively treat water with changes to DOM
DB DBP & & DO DOM in in t the NW NWT • Untreated water samples • Higher THM than HAA concentrations • Larger, more terrestrial-like DOM forms higher concentrations of DBP • Increased permafrost thaw + increases to terrestrial DOM observed in other circumpolar nations • Complicates drinking water treatment options in the NWT
Thank You; Mahsi Cho; Merci • All communities and participants • Mylene Ratelle, Heidi Swanson • Students and staff • Danielle Brandow, Leicester Fung, Sara Packull-McCormick, Aaron Tang, Jean Napenas, Christina Lam, Victoria Leger • GNWT Dept of Health and Social Services • Community and Regional Partners • Collaborators, co-investigators, • And many more….. Funding and support from: NCP, NWF, Health Canada, NSERC, School of Public Health and Health Systems, University of Waterloo
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