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Objectives. We compared the ability of several heat--health warning systems to predict days of heat-associated mortality using common data sets. Methods. Heat-health warning systems initiate emergency public health interventions once forecasts have identified weather conditions to breach predetermined trigger levels. We examined 4 commonly used trigger-setting approaches: (1) synoptic classification, (2) epidemiologic assessment of the temperature--mortality relationship, (3) temperature--humidity index, and (4) physiologic classification. We applied each approach in Chicago, Illinois; London, United Kingdom; Madrid, Spain; and Montreal, Canada, to identify days expected to be associated with the highest heat-related mortality. Results. We found little agreement across the approaches in which days were identified as most dangerous. In general, days identified by temperature-mortality assessment were associated with the highest excess mortality. Conclusions. Triggering of alert days and ultimately the initiation of emergency responses by a heat-health warning system varies significantly across approaches adopted to establish triggers. (Am J Public Health. 2010;100: 1137-1144. doi: 10.2105/AJPH.2009.169748)

BACKGROUND: Congenital heart defects may be environmentally related, but the association with elevated ambient temperature has received little attention. OBJECTIVES: We studied the relationship between outdoor heat during the first trimester of pregnancy and risk of congenital heart defects. METHODS: We carried out a retrospective cohort study of 704,209 fetuses between 2 and 8 weeks postconception from April to September in Quebec, Canada, 1988-2012. We calculated the prevalence of congenital heart defects at birth according to the number of days women were exposed to maximum temperature ≥ 30°C. In log-binomial regression models, we estimated prevalence ratios (PR) and 95% confidence intervals (CI) for the relationship of temperature with seven critical and eight noncritical heart defects, adjusted for pregnancy characteristics. RESULTS: Prevalence of congenital heart defects was 979.5 per 100,000 for 10 days or more of temperature ≥ 30°C compared with 878.9 per 100,000 for 0 days of exposure. Temperature was more precisely associated with noncritical than critical defects, which had lower prevalence. Fetuses exposed to 15 days of temperature ≥ 30°C between 2 and 8 weeks post-conception had 1.06 times the risk of critical defects (95% CI: 0.67, 1.67) and 1.12 times the risk of noncritical defects (95% CI: 0.98, 1.29) relative to 0 days. Associations were higher for atrial septal defects (PR 1.37, 95% CI: 1.10, 1.70) than for other noncritical defects. For atrial septal defects, associations with elevated temperatures began the 3rd week postconception. CONCLUSIONS: Extreme heat exposure during the first trimester may be associated with noncritical heart defects, especially of the atrial septum. http://dx.doi.org/10.1289/EHP171., Introduction Congenital heart defects are a leading congenital anomaly worldwide, occurring in every 8 live births per 1,000 (van der Linde et al. 2011). Most congenital heart defects are noncritical, [...]

Background: As the COVID-19 pandemic continues to unfold, increasing numbers of Canadians have self-medicated with ivermectin, an antiparasitic drug used to treat infections and infestations in humans and livestock. This is despite a lack of goodquality evidence for its efficacy in preventing and treating infection with SARS CoV-2. Concerns over unsafe use of ivermectin prompted a review of calls to the British Columbia Drug and Poison Information Centre. Methods: We performed a descriptive analysis of calls received from 1 January 2018 to 11 October 2021 about exposure to ivermectin and related compounds. Results: The BC Drug and Poison Information Centre received 50 calls concerning exposure to ivermectin and related compounds during the period we studied. Prior to the COVID-19 pandemic, 23 calls were made, and all but one were unintentional exposures. The first ivermectin call referencing COVID-19 was received in March 2021, after which call frequency increased, leading to 27 more calls, of which 19 were intentional exposures to ivermectin referencing COVID-19. Of these calls, 11 concerned veterinary-grade ivermectin, and where doses were calculable, at 0.147-11.91 mg/kg, they were above the 0.15-0.2mg/kg therapeutic dose for most approved human uses. Three exposures were asymptomatic, 11 were considered to have minor effects, 1 was moderate, 4 were symptomatic but considered unrelated to ivermectin, and in 1 case symptoms were not recorded. Conclusions: The use of ivermectin to prevent or treat COVID-19 is occurring in British Columbia, and both human and veterinary formulations are being ingested. Our case review suggests that these exposures occur most frequently in more agricultural regions, where the portion of adults vaccinated against COVID-19 has been lower and the portion infected higher than elsewhere in the province. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear. OBJECTIVE: We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants. METHOD: An open cohort of children born in the province of Quebec, Canada, was created using linked medical-administrative databases. New cases of asthma were defined as one hospital discharge with a diagnosis of asthma or two physician claims for asthma within a 2 year period. Annual ozone ([O.sub.3]) levels were estimated at the child's residence for all births 1999-2010, and nitrogen dioxide (N[O.sub.2]) levels during 1996-2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (P[M.sub.2.5]) were estimated at a 10 km x 10 km resolution and assigned to residential postal codes throughout the province (1996-2011). Hazard ratios (HRs) were assessed with Cox models for the exposure at the birth address and for the time-dependent exposure. We performed an indirect adjustment for secondhand smoke (SHS). RESULTS: We followed 1,183,865 children (7,752,083 person-years), of whom 162,752 became asthmatic. After controlling for sex and material and social deprivation, HRs for an interquartile range increase in exposure at the birth address to N[O.sub.2] (5.45 ppb), [O.sub.3] (3.22 ppb), and P[M.sub.2.5] (6.50 µg/[m.sup.3]) were 1.04 (95% CI: 1.02, 1.05), 1.11 (95% CI: 1.10, 1.12), and 1.31 (95% CI: 1.28, 1.33), respectively. Effects of [O.sub.3] and P[M.sub.2.5] estimated with time-varying Cox models were similar to those estimated using exposure at birth, whereas the effect of N[O.sub.2] was slightly stronger (HR = 1.07; 95% CI: 1.05, 1.09). CONCLUSIONS: Asthma onset in children appears to be associated with residential exposure to P[M.sub.2.5], [O.sub.3] and N[O.sub.2]. http://dx.doi.org/10.1289/ehp.1509838, Introduction Asthma is one of the most common childhood chronic diseases worldwide (Asher et al. 2006; Garner and Kohen 2008; Williams et al. 1999). Although the link between exposure to [...]

Background: Climate change may lead to more severe and extreme heat waves in the future, but its potential impact on sudden infant death--a leading cause of infant mortality--is unclear. Objectives: We sought to determine whether risk of sudden infant death syndrome (SIDS) is elevated during hot weather. Methods: We undertook a case-crossover analysis of all sudden infant deaths during warm periods in metropolitan Montreal, Quebec, Canada, from 1981 through 2010. Our analysis included a total of 196 certified cases of SIDS, including 89 deaths at 1-2 months of age, and 94 at 3-12 months. We estimated associations between maximum outdoor temperatures and SIDS by comparing outdoor temperatures on the day of or day before a SIDS event with temperatures on control days during the same month, using cubic splines to model temperature and adjusting for relative humidity. Results: Maximum daily temperatures of > 29[degrees]C on the same day were associated with 2.78 times greater odds of sudden infant death relative to 20[degrees]C (95% CI: 1.64, 4.70). The likelihood of sudden death increased steadily with higher temperature. Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29[degrees]C compared with 20[degrees]C on the day of the event. Conclusions: High ambient temperature may be a novel risk factor for SIDS, especially at [greater than or equal to] 3 months of age. Climate change and the higher temperatures that result may account for a potentially greater proportion of sudden infant deaths in the future., Introduction Sudden infant death syndrome (SIDS) is a leading cause of death among infants 1-12 months of age, but its underlying risk factors are poorly understood (Kinney and Thach 2009; [...]

In late 1987, an outbreak of illness occurred in Canada in which the patients developed gastrointestinal symptoms, sometimes with neurological complications. The only feature all the patients had in common was that they had eaten mussels from Prince Edward Island. A total of 107 cases were clearly identified, though the number of actual cases is almost certainly larger. Some patients experienced severe neurological complications, which included apparently irreversible damage to the mechanisms of short-term memory; these neurological complications are the subject of a companion article in the June 21, 1990 issue of The New England Journal of Medicine. Three patients died. Many organisms concentrate substances in their bodies which can pose problems for the larger creatures who eat them, and mussels are capable of concentrating a variety of environmental toxins in their bodies. However, in this case, the only poisonous compound which could be identified was domoic acid. Domoic acid is an amino acid which can excite nervous tissue, like the biochemically similar compounds glutamic acid and kainic acid. The source of the domoic acid in the mussels appears to be the microscopic creature Nitzschia pungens, which biologists refer to as a pennate phytoplanktonic diatom. The tiny creatures were eaten by the mussels, which concentrated the poisonous domoic acid in their tissues. Steps have now been taken in Canada to monitor the level of domoic acid in mussels prior to their commercial distribution. (Consumer Summary produced by Reliance Medical Information, Inc.)

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. [ABSTRACT FROM AUTHOR]