Hot weather and death related to acute cocaine, opioid and amphetamine toxicity in British Columbia, Canada: a time-stratified case-crossover study.

BACKGROUND: Previous research has shown that cocaine-associated deaths occur more frequently in hot weather, which has not been described for other illicit drugs or combinations of drugs. The study objective was to evaluate the relation between temperature and risk of death related to cocaine, opioids and amphetamines in British Columbia, Canada. METHODS: We extracted data on all deaths with cocaine, opioid or amphetamine toxicity recorded as an underlying or contributing cause from BC vital statistics for 1998-2017. We used a time-stratified case-crossover design to estimate the effect of temperature on the risk of death associated with acute drug toxicity during the warmer months (May through September). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for each 10°C increase in the 2-day average maximum temperature at the residential location. RESULTS: We included 4913 deaths in the analyses. A 10°C increase in the 2-day average maximum temperature was associated with an OR of 1.43 (95% CI 1.11-1.86) for deaths with only cocaine toxicity recorded (n = 561), an OR of 1.15 (95% CI 0.99-1.33) for deaths with opioids only (n = 1682) and an OR of 1.11 (95% CI 0.60-2.04) for deaths with amphetamines only (n = 133). There were also elevated effects when toxicity from multiple drugs was recorded. Sensitivity analyses showed differences in the ORs by sex, by climatic region, and when the location of death was used instead of the location of residence. INTERPRETATION: Increasing temperatures were associated with higher odds of death due to drug toxicity, especially for cocaine alone and combined with other drugs. Targeted interventions are necessary to prevent death associated with toxic drug use during hot weather.

Kratom exposures managed by the British Columbia poison centre, 2012-2019: a descriptive analysis.

BACKGROUND: Kratom, a plant indigenous to Southeast Asia, which has been used both recreationally and in the treatment of pain and opioid dependence, has received little scrutiny in the United States and almost none in Canada. We analyzed calls to the British Columbia poison centre to describe caller-declared exposures to kratom and the acute health effects of these exposures. METHODS: For this descriptive analysis, we accessed electronic records, including transcriptions and extracted variables, of calls specifying kratom exposure managed by the BC Drug and Poison Information Centre (DPIC) from 2012 to 2019. We describe changes in case numbers, reasons for exposure, concurrent drug exposures and clinical outcomes over the study period. RESULTS: We identified 32 cases during the study period. In 23 cases (72%), the DPIC was consulted by a health care worker. Case numbers increased from 0 in 2012 to 9 in 2019. Numbers were highest for males in their 20s (n = 17, 53%). A total of 27 cases (84%) involved ingestion, with online distributors and local stores named as sources of procurement. A concurrent drug exposure was identified in 13 (41%) cases. There were no deaths; in 1 case, the exposed individual was intubated to manage agitation following kratom withdrawal. INTERPRETATION: We observed a steady increase in kratom-related poison centre calls from 2012 to 2019, especially in young adult males. Rising call numbers may reflect increasing availability of kratom and may be a consequence of BC's opioid crisis, with kratom used by some to lessen symptoms of opioid withdrawal.

Improving attribution of extreme heat deaths through interagency cooperation.

Attributing individual deaths to extreme heat events (EHE) in Canada and elsewhere is important for understanding the risk factors, protective interventions, and burden of mortality associated with climate change. However, there is currently no single mechanism for identifying individual deaths due to EHE and different agencies have taken different approaches, including (1) vital statistics coding based on medical certificates of death, (2) probabilistic methods, and (3) enhanced surveillance. The 2018 EHE in Montréal provides an excellent case study to compare EHE deaths identified by these different approaches. There were 353 deaths recorded in the vital statistics data over an 8-day period, of which 102 were potentially attributed to the EHE by at least one approach and 251 were not attributed by any approach. Only nine of the 102 deaths were attributed to the EHE by all three approaches, 23 were attributed by two approaches, and 70 were attributed by only one approach. Given that there were approximately 50 excess deaths during the EHE, it remains unclear exactly which of the total 353 deaths should be attributed to the extreme temperatures. These results highlight the need for a more systematic and cooperative approach to EHE mortality in Canada, which will continue to increase as the climate changes.

RéSUMé: L'attribution des décès individuels aux épisodes de chaleur accablante (ECA) au Canada et ailleurs est importante pour comprendre les facteurs de risque, les interventions de protection et le fardeau de la mortalité associés aux changements climatiques. Cependant, il n'existe actuellement aucun mécanisme unique pour identifier les décès individuels dus à l'ECA et différentes agences ont adopté différentes approches, notamment (1) le codage des statistiques de l'état civil basé sur les certificats médicaux de décès, (2) des méthodes probabilistes et (3) une surveillance renforcée. L'ECA 2018 à Montréal fournit une excellente étude de cas pour comparer les décès ECA identifiés par ces différentes approches. Il y a eu 353 décès enregistrés dans les données des statistiques de l'état civil sur une période de 8 jours, dont 102 ont été potentiellement attribués à l'ECA par au moins une approche et 251 n'ont été attribués par aucune approche. Seuls neuf des 102 décès ont été attribués à l'ECA par les trois approches, 23 ont été attribués par deux approches et 70 ont été attribués par une seule approche. Étant donné qu'il y a eu environ 50 décès supplémentaires pendant l'ECA, on ne sait pas exactement lequel des 353 décès au total doit être attribué aux températures extrêmes. Ces résultats soulignent la nécessité d'une approche plus systématique et coopérative de la mortalité ECA au Canada, qui continuera d'augmenter à mesure que le climat change.

Analysis of community deaths during the catastrophic 2021 heat dome: Early evidence to inform the public health response during subsequent events in greater Vancouver, Canada.

BACKGROUND: British Columbia, Canada, was impacted by a record-setting heat dome in early summer 2021. Most households in greater Vancouver do not have air conditioning, and there was a 440% increase in community deaths during the event. Readily available data were analyzed to inform modifications to the public health response during subsequent events in summer 2021 and to guide further research. METHODS: The 434 community deaths from 27 June through 02 July 2021 (heat dome deaths) were compared with all 1,367 community deaths that occurred in the same region from 19 June through 09 July of 2013-2020 (typical weather deaths). Conditional logistic regression was used to examine the effects of age, sex, neighborhood deprivation, and the surrounding environment. Data available from homes with and without air conditioning were also used to illustrate the indoor temperatures differences. RESULTS: A combined index of material and social deprivation was most predictive of heat dome risk, with an adjusted odds ratio of 2.88 [1.85, 4.49] for the most deprived category. Heat dome deaths also had lower greenness within 100 m than typical weather deaths. Indoor temperatures in one illustrative home without air conditioning ranged between 30°C and 40°C. CONCLUSIONS: Risk of death during the heat dome was associated with deprivation, lower neighborhood greenness, older age, and sex. High indoor temperatures likely played an important role. Public health response should focus on highly deprived neighborhoods with low air conditioning prevalence during extreme heat events. Promotion of urban greenspace must continue as the climate changes.

Changing Trends in Paralytic Shellfish Poisonings Reflect Increasing Sea Surface Temperatures and Practices of Indigenous and Recreational Harvesters in British Columbia, Canada.

Paralytic shellfish poisoning (PSP) occurs when shellfish contaminated with saxitoxin or equivalent paralytic shellfish toxins (PSTs) are ingested. In British Columbia, Canada, documented poisonings are increasing in frequency based on 62 investigations identified from 1941-2020. Two PSP investigations were reported between 1941 and 1960 compared to 31 since 2001 (p < 0.0001) coincident with rising global temperatures (r2 = 0.76, p < 0.006). The majority of PSP investigations (71%) and cases (69%) were linked to self-harvested shellfish. Far more investigations involved harvests by indigenous communities (24%) than by commercial and recreational groups. Single-case-exposure investigations increased by more than 3.5 times in the decade 2011-2020 compared to previous periods. Clams (47%); mussels (26%); oysters (14%); scallops (6%); and, in more recent years, crabs (4%) were linked to illnesses. To guide understanding of self-harvesting consumption risks, we recommend collecting data to determine when PST-producing algae are present in high concentrations, improving the quality of data in online shellfish harvest maps to include dates of last testing; biotoxin testing results; and a description of bivalve species tested. Over reliance on toxin results in biomonitored species may not address actual consumption risks for unmonitored species harvested from the same area. We further recommend introducing phytoplankton monitoring in remote indigenous communities where self-harvesting is common and toxin testing is unavailable, as well as continuing participatory education about biotoxin risks in seafoods.

A descriptive analysis of blood mercury test results in British Columbia to identify excessive exposures.

OBJECTIVE: The objective of this study was to describe who in British Columbia (BC) is tested for blood mercury, the distribution of their results, and the adequacy of follow-up testing. METHODS: The BC Centre for Disease Control (BCCDC) obtained records of clinician-ordered analyses of blood mercury conducted by BC laboratories during 2009 and 2010. We conducted a descriptive analysis with statistical testing of who was tested, the distribution of their blood mercury concentrations, whose results exceeded Health Canada's proposed guidance values (8 µg/L (40 nmol/L) for children/adolescents ≤ 18 years and women 19-49 years, and 20 µg/L (100 nmol/L) for other adults), and patterns of repeat testing. RESULTS: Mercury test results for 6487 individuals were reviewed. Adults ≥ 50 years had the highest testing rates. The median blood mercury concentration for all tested persons was 1.8 µg/L. Nine percent of women aged 19-49 years had results exceeding Health Canada's provisional guidance value of 8 µg/L. Data from one of BC's two biomarker laboratories indicated that some residents of Vancouver and nearby suburbs have higher exposure to mercury than other BC residents. Of 127 individuals who had results in 2009 exceeding provisional guidance values, only 45% were tested again within 12 months. CONCLUSION: Collating and analyzing all clinical biomarker testing such as blood mercury at a provincial population level allows for assessment of the adequacy and appropriateness of follow-up testing and suggests which regional and demographic strata are at higher levels of exposure.

RéSUMé: OBJECTIF: Décrire qui, en Colombie-Britannique (C.-B.), fait l'objet de dosages du mercure sanguin, quelle est la distribution des résultats, et si les dosages de suivi sont adéquats. MéTHODE: Le BC Centre for Disease Control (BCCDC) a obtenu les dossiers de dosages du mercure sanguin demandés par les cliniciens et effectués par les laboratoires de la province en 2009 et 2010. Nous avons effectué une analyse descriptive avec des contrôles statistiques des personnes testées, de la distribution de leurs concentrations de mercure sanguin, des sujets dont les résultats dépassaient les valeurs provisoires indiquées par Santé Canada (8 µg/L [40 nmol/L] pour les enfants/adolescents de ≤ 18 ans et les femmes de 19-49 ans et 20 µg/L [100 nmol/L] pour les autres adultes) et des tendances des dosages ultérieurs. RéSULTATS: Les résultats des dosages du mercure de 6 487 personnes ont été examinés. Les taux de dosage les plus élevés ont été observés chez les adultes de ≥ 50 ans. La concentration médiane de mercure sanguin chez toutes les personnes testées était de 1,8 µg/L. Neuf p. cent des femmes de 19 à 49 ans présentaient des résultats supérieurs à la valeur provisoire de 8 µg/L indiquée par Santé Canada. Selon les données de l'un des deux laboratoires de biomarqueurs de la C.-B., l'exposition au mercure de certains résidents de Vancouver et des banlieues proches était supérieure à celle des autres résidents de la province. Sur les 127 personnes dont les résultats en 2009 dépassaient les valeurs provisoires indiquées, 45 % seulement ont fait l'objet d'un nouveau dosage dans un délai de 12 mois. CONCLUSION: La collecte et l'analyse de tous les essais cliniques sur les biomarqueurs comme le mercure sanguin à l'échelle d'une population provinciale permettent de déterminer l'adéquation et la pertinence des dosages de suivi et indiquent dans quelles strates régionales et démographiques les niveaux d'exposition sont les plus élevés.

Social connection as a public health adaptation to extreme heat events.

Climate change is an increasingly important public health issue, reflected in morbidity and mortality outcomes during extreme heat events. At the same time, the harms of social isolation with respect to a wide range of health outcomes are becoming better understood. Given that older adults are at higher risk during hot weather and at higher risk of social isolation, they are among those at highest risk for adverse impacts of extreme heat events. While specific strategies to reduce heat exposure have been described in the literature and promoted in public health practice, these may not be readily available to socially isolated older adults. As such, it is crucial to identify key approaches to address risk due to social isolation in the aging population, and to acknowledge their limitations and barriers. Interventions rooted in social connection, a concept widely applied in interventions for public health and social well-being, should be applied as a tool for adaptation to extreme heat events.

RéSUMé: Le changement climatique est un problème de santé publique de plus en plus important, qui se reflète dans les résultats de la morbidité et de la mortalité lors des épisodes de chaleur extrême. Au même temps, les mals de l'isolement social en ce qui concerne un large éventail de résultats pour la santé sont de mieux en mieux compris. Étant donné que les personnes âgées sont plus à risque durant les temps chaud et à risque d'isolement social, elles font partie des personnes les plus exposées aux effets négatifs d'événements de chaleur extrême. Bien que des stratégies spécifiques pour réduire l'exposition à la chaleur aient été décrites dans la littérature et promues dans la pratique de la santé publique, elles peuvent ne pas être facilement accessibles aux personnes âgées socialement isolées. Comme tel, il est essentiel d'identifier les approches clés pour réduire les risques dus à l'isolement social de la population vieillissante et de reconnaître leurs limites et obstacles. Les interventions enracinées dans la connexion sociale, un concept largement appliqué dans les interventions pour la santé publique et le bien-être social, devraient être appliquées comme un outil d'adaptation aux événements de chaleur extreme.

Snowfall, Temperature, and the Risk of Death From Myocardial Infarction: A Case-Crossover Study.

Previous research has associated snowfall with risk of myocardial infarction (MI). Most studies have been conducted in regions with harsh winters; it remains unclear whether snowfall is associated with risk of MI in regions with milder or more varied climates. A case-crossover design was used to investigate the association between snowfall and death from MI in British Columbia, Canada. Deaths from MI among British Columbia residents between October 15 and March 31 from 2009 to 2017 were identified. The day of each death from MI was treated as the case day, and each case day was matched to control days drawn from the same day of the week during the same month. Daily snowfall amount was assigned to case and control days at the residential address, using weather stations within 15 km of the residence and 100 m in elevation. In total, 3,300 MI case days were matched to 10,441 control days. Compared with days that had no snowfall, odds of death from MI increased 34% (95% confidence interval: 0%, 80%) on days with heavy snowfall (≥5 cm). In stratified analysis of deaths from MI as a function of both maximum temperature and snowfall, risk was significantly increased on snowfall days when the temperature was warmer.

Hot weather and risk of drowning in children: Opportunity for prevention.

The link between outdoor temperature and risk of drowning in children is poorly understood. The objective of this study was to determine the association between elevated temperature and the chance of drowning in children and adolescents. We used a case-crossover study design to assess 807 fatal and nonfatal drowning-related hospitalisations among children aged 0 to 19 years in Quebec, Canada between 1989 and 2015. The primary exposure measure was maximum temperature the day of drowning. We estimated odds ratios and 95% confidence intervals (CI) for the association of temperature with drowning by age group (<2, 2-4, 5-9, 10-19 years), adjusted for precipitation, relative humidity, and holidays. Elevated temperature was associated with greater odds of drowning. Compared with 15 °C, a temperature of 30 °C was associated with 6 times the chance of drowning between 0 and 19 years of age (95% CI 4.40-8.16). The association was not modified by characteristics such as age or location of drowning. Relative to 15 °C, a temperature of 30 °C was associated with 3.75 times the odds of drowning in pools (95% CI 1.85-7.63) and 12.44 times the odds of drowning in other bodies of water (95% CI 3.53-43.81). Associations persisted even after implementation of a policy to restrict access to private pools in 2010. These findings suggest that hot weather is strongly associated with the risk of drowning in children aged 0 to 19 years. Interventions to prevent drowning in children should be enhanced during hot days, and not only around pools.

Electronic cigarette exposures reported to the British Columbia Drug and Poison Information Centre: an observational case series.

BACKGROUND: Electronic nicotine delivery systems (ENDSs), including electronic cigarettes (e-cigarettes), are rapidly gaining popularity. The aim of this study was to use poison centre data to describe epidemiological trends in ENDS-related exposures. METHODS: We conducted an observational case series study using records containing both coded fields and free-text narratives from the British Columbia Drug and Poison Information Centre for all calls involving exposure to ENDS received from 2012 to 2017. We described trends in exposures and exposed people, as well as clinical effects. RESULTS: A total of 243 calls were recorded for 186 unique exposures to ENDS devices, e-juice, e-cigarette cartridges and other associated paraphernalia over the study period. Calls related to ENDS exposures increased nearly sixfold between 2013 and 2014 and did not decline subsequently. Exposures were most frequently documented in children aged 4 years or less (81 [43.5%]), with 58 (31.0%) in 1- and 2-year-olds. Seventy-two exposures (89%) in children aged 4 years or less were due to accidental ingestion, whereas adults aged 25 years or more called the poison centre following ENDS malfunctions (7 [23%], spills (4 [13%]) and exposure to e-juice mistaken for other substances (4 [13%]). Of the 186 exposed people, 87 (46.8%) reported symptoms. INTERPRETATION: British Columbia experienced a sixfold increase in ENDS-related calls to the provincial poison centre between 2012 and 2017, driven by ingestions in young children. Regulatory approaches aimed at minimizing children's access to ENDS, clear labelling of nicotine concentration, and packaging that reduces the likelihood of spills, product confusion and malfunction should be considered.

Residential exposure to electromagnetic fields during pregnancy and risk of child cancer: A longitudinal cohort study.

OBJECTIVE: We assessed whether exposure to electromagnetic fields during pregnancy increases the risk of childhood cancer. METHODS: We studied a retrospective cohort of 784,944 newborns in Quebec, Canada between 2006 and 2016 who were followed for cancer one decade after birth. The exposures were residential distance to the nearest high voltage power transformer station and transmission line. We determined the incidence of childhood cancer, and estimated hazard ratios and 95% confidence intervals (CI) in Cox proportional hazards regression models adjusted for maternal and birth characteristics. RESULTS: There were 1114 incident cases of cancer during 4,647,472 person-years of follow-up. Residential proximity to transformer stations was associated with a somewhat greater risk of cancer, but there was no association with transmission lines. Compared with 200 m, a distance of 80 m from a transformer station was associated with a hazard ratio of 1.08 (95% CI 0.98, 1.20) for any cancer, 1.04 (95% CI 0.88, 1.23) for hematopoietic cancer, and 1.11 (95% CI 0.99, 1.25) for solid tumours. CONCLUSIONS: Residential proximity to transformer stations is associated with a borderline risk of childhood cancer, but the absence of an association with transmission lines suggests no causal link.

Maternal proximity to extremely low frequency electromagnetic fields and risk of birth defects.

Causes of birth defects are unclear, and the association with electromagnetic fields is inconclusive. We assessed the relationship between residential proximity to extremely low frequency electromagnetic fields from power grids and risk of birth defects. We analyzed a population-based sample of 2,164,246 infants born in Quebec, Canada between 1989 and 2016. We geocoded the maternal residential postal code at delivery and computed the distance to the nearest high voltage electrical transmission line or transformer station. We used log-binomial regression to estimate risk ratios (RR) and 95% confidence intervals (CI) for the association of residential proximity to transmission lines and transformer stations with birth defects, adjusting for maternal and infant characteristics. The prevalence of birth defects within 200 m of a transmission line (579.4 per 10,000 per live births) was only slightly higher compared with distances further away (568.7 per 10,000). A similar trend was seen for transformer stations. Compared with 200 m, a distance of 50 m was not associated with the risk of birth defects for transmission lines (RR 1.00, 95% CI 1.00-1.01) and transformer stations (RR 1.01, 95% CI 1.00-1.03). There was no consistent association when we examined birth defects in different organ systems. We found no compelling evidence that residential proximity to extremely low frequency electromagnetic fields from electrical power grids increases the risk of birth defects. Women residing near electrical grids can be reassured that an effect on the risk of birth defects is unlikely.

Effects of cold temperature and snowfall on stroke mortality: A case-crossover analysis.

BACKGROUND: We sought to determine if cold temperature and snowfall are independently associated with stroke mortality, and whether effects differ between hemorrhagic and ischemic stroke. MATERIALS AND METHODS: We conducted a case-crossover study of 13,201 stroke deaths utilizing weather records between the months of November and April for Quebec, Canada from 1981 to 2015. We compared exposure to cold temperature and snowfall with controls days when stroke death did not occur. We computed odds ratios (OR) and 95% confidence intervals (CI) for the association of minimum temperature and duration of snowfall with stroke, adjusted for change in barometric pressure and relative humidity. RESULTS: The likelihood of mortality the day following exposure to cold temperature was elevated for hemorrhagic stroke in men, independent of snowfall. Relative to 0 °C, a temperature of -20 °C was associated with 1.17 times the odds of hemorrhagic stroke death (95% CI 1.04-1.32). An independent effect of snowfall was also present in men, with 12 h of snowfall associated with 1.12 times the odds of hemorrhagic stroke death (95% CI 1.00-1.24) compared with no snowfall. There was no evidence of an increased risk in women. Cold temperature and snowfall were not associated with ischemic stroke death in either men or women. CONCLUSION: Our results suggest that cold temperature and snowfall are independent risk factors for death from hemorrhagic stroke in men. These findings imply that interventions to prevent fatal hemorrhagic stroke during winter should include both cold temperature exposure and snowfall in men.

Public health should promote co-operative housing and cohousing.

In promoting healthier built environments, attention worldwide has focused largely on streetscapes and recreational spaces, with less regard given to housing form, in particular to the health effects of communal housing. Research demonstrates that communal housing models, such as cohousing and co-operative housing, promote social inclusion, and increase the perceived well-being and mental and physical health of residents, particularly of seniors. In Canada, relative to other countries, there is a paucity of evidence for the health effects of co-operatives and cohousing. Historically, some Indigenous communities constructed longhouses, connected dwellings situated around common areas, a form which may still be useful in promoting healthy communities. In this commentary, we suggest that improving access to co-operative and communal housing is an important area for public health involvement.

A population-based birth cohort study of the association between childhood-onset asthma and exposure to industrial air pollutant emissions.

BACKGROUND: Studies of the association between air pollution and asthma onset have mostly focused on urban and traffic-related air pollution. We investigated the associations between exposure to industrial emissions and childhood-onset asthma in a population-based birth cohort in Quebec, Canada, 2002-2011. METHODS: The cohort was built from administrative health databases. We developed separately for PM2.5 and SO2 different metrics representing children's time-varying residential exposure to industrial emissions: 1) yearly number of tons of air pollutant emitted by industries located within 2.5 km of the residence; 2) distance to the nearest "major emitter" (≥100 tons) of either PM2.5 and SO2 within 7.5 km of the residence, and; 3) tons of air pollutant emitted by the nearest "major emitter" within 7.5 km, weighted by the inverse of the distance and the percentage of time that the residence was downwind. To handle the large number of zeros (i.e., children unexposed) we decomposed the exposure variable into two covariates simultaneously included in the regression model: a binary indicator of exposure and a continuous exposure variable centered at the mean value among exposed children. We performed Cox models using age as the time axis, adjusted for gender, material and social deprivation and calendar year. We indirectly adjusted for unmeasured secondhand smoke. RESULTS: The cohort included 722,667 children and 66,559 incident cases of asthma. Across the different exposure metrics, mean percentage changes in the risk of asthma onset in children exposed to the mean relative to those unexposed ranged from 4.5% (95% CI: 2.8, 6.3%) to 10.6% (95% CI: 6.2, 15.2%) for PM2.5 and, from 1.1% (95% CI: -0.1, 3.3%) to 8.9% (95% CI: 7.1, 11.1%) for SO2. Indirect adjustment for secondhand smoke did not substantially affect the associations. In children exposed, the risk of asthma onset increased with the magnitude of the exposure for all metrics, except the distance to the nearest major emitter of SO2. CONCLUSIONS: In this population-based birth cohort, residential exposure to industrial air pollutant emissions was associated with childhood-onset asthma. Additional studies with improved models for estimating exposure to industrial point-sources are needed to further support the observed associations.

Establishing Heat Alert Thresholds for the Varied Climatic Regions of British Columbia, Canada.

Following an extreme heat event in 2009, a Heat Alert and Response System (HARS) was implemented for the greater Vancouver area of British Columbia (BC), Canada. This system has provided a framework for guiding public health interventions and assessing population response and adaptation to extreme heat in greater Vancouver, but no other parts of BC were covered by HARS. The objective of this study was to identify evidence-based heat alert thresholds for the Southwest, Southeast, Northwest, and Northeast regions to facilitate the introduction of HARS across BC. This was done based on a national approach that considers high temperatures on two consecutive days and the intervening overnight low, referred to as the high-low-high approach. Daily forecast and observed air temperatures and daily mortality counts for May through September of 2004 through 2016 were obtained. For each date (dayt), dayt-2 forecasts were used to assign high temperatures for dayt and dayt+1 and the overnight low. A range of high-low-high threshold combinations was assessed for each region by finding associations with daily mortality using time-series models and other considerations. The following thresholds were established: 29-16-29 °C in the Southwest; 35-18-35 °C in the Southeast; 28-13-28 °C in the Northwest; and 29-14-29 °C in the Northeast. Heat alert thresholds for all regions in BC provide health authorities with information on dangerously hot temperature conditions and inform the activation of protective public health interventions.

Leveraging the Canadian Health Measures Survey for environmental health research.

Since 2007, the nationally representative, cross-sectional Canadian Health Measures Survey (CHMS) has collected detailed health and exposure data from more than 25,000 Canadians, including a wide range of chemical biomarkers analyzed in blood, urine, and environmental media. This article highlights the extent to which the CHMS dataset has been used in the peer-reviewed environmental health literature and opportunities for further expanding usage of the dataset. A literature search (2007-2018) was performed to identify peer-reviewed studies that have made substantive use of the CHMS dataset. Studies were analyzed according to the study type, data usage, populations studied, environmental health themes, citation/publication data, and institutional collaborations. A total of 51 environmental-health related CHMS studies were identified, including studies related to indoor and outdoor air quality, the built environment, and chemical and environmental tobacco smoke exposures. Health indicator data are being increasingly exploited, as is the ability to combine cycle datasets over time. Although these studies covered a range of environmental exposures, many CHMS variables remain underutilized. The CHMS dataset provides a valuable portrait of chemical exposures in Canadians of all ages, linked to a wide variety of health indicators. Many opportunities remain to exploit and expand both the use of the dataset and collaborations between Canadian agencies and domestic and international research institutions.

Blood mercury, lead and cadmium levels and determinants of exposure among newcomer South and East Asian women of reproductive age living in Vancouver, Canada.

BACKGROUND: Biomarkers of the reproductive and neuro-developmental toxicants mercury (Hg), lead (Pb) and cadmium (Cd) have been found at higher concentrations in women born outside Canada than in Canadian-born women. We measured blood Hg, Pb and Cd in women ages 19 to 45years living in greater Vancouver (Canada) within five years of their arrival from South Asia (India) or East Asia (mainland China, Hong Kong and Taiwan) and related their biomarker concentration levels with exposures and behaviors since their coming to Canada. METHODS: Participants were recruited through advertisements in relevant ethnic media, locations and groups. Concentrations of blood Hg, Pb and Cd were analyzed by inductively coupled plasma-mass spectrometry (ICP-Q-MS) and compared with population values. Biomarker concentrations were regressed against exposures and behaviors assessed by culturally-relevant questionnaire. RESULTS: The study recruited 53 South and 111 East Asian women. Median (95th percentile) blood Pb in South Asians was 1.15 (2.71) µg/dL compared with 1.01 (1.81) µg/dL in East Asians. On the other hand, blood Hg at 2.5 (7.3) µg/L was higher in East Asians compared to 0.20 (0.83) µg/L in South Asians. Blood Cd was also higher in the East Asian group: East 0.53 (1.1) µg/L; South 0.27 (0.82) µg/L. Higher blood Hg was associated with seafood consumption, dental amalgams and traditional remedies; blood Pb with home renovations, sucking on metal jewelry, and cosmetics. Blood Pb and Cd concentrations were inversely associated with dairy consumption. CONCLUSIONS: Asian women recently arrived in Vancouver had higher blood Hg, Pb and Cd concentrations than same-age Canadian women measured in a national survey. Among South Asian newcomer women of reproductive age, exposure to Cd may continue after arrival. Local exposures to Hg occur through seafood and potentially through ingestion of imported traditional remedies.