Cold-related Mortality Research Articles

Two-way effect modifications of air pollution and air temperature on total natural and cardiovascular mortality in eight European urban areas

BackgroundAlthough epidemiological studies have reported associations between mortality and both ambient air pollution and air temperature, it remains uncertain whether the mortality effects of air pollution are modified by temperature and vice versa. Moreover, little is known on the interactions between ultrafine particles (diameter ≤ 100 nm, UFP) and temperature. ObjectiveWe investigated whether the short-term associations of particle number concentration (PNC in the ultrafine range (≤100 nm) or total PNC ≤ 3000 nm, as a proxy for UFP), particulate matter ≤ 2.5 μm (PM2.5) and ≤ 10 μm (PM10), and ozone with daily total natural and cardiovascular mortality were modified by air temperature and whether air pollution levels affected the temperature-mortality associations in eight European urban areas during 1999–2013. MethodsWe first analyzed air temperature-stratified associations between air pollution and total natural (nonaccidental) and cardiovascular mortality as well as air pollution-stratified temperature-mortality associations using city-specific over-dispersed Poisson additive models with a distributed lag nonlinear temperature term in each city. All models were adjusted for long-term and seasonal trend, day of the week, influenza epidemics, and population dynamics due to summer vacation and holidays. City-specific effect estimates were then pooled using random-effects meta-analysis. ResultsPooled associations between air pollutants and total and cardiovascular mortality were overall positive and generally stronger at high relatively compared to low air temperatures. For example, on days with high air temperatures (>75th percentile), an increase of 10,000 particles/cm3 in PNC corresponded to a 2.51% (95% CI: 0.39%, 4.67%) increase in cardiovascular mortality, which was significantly higher than that on days with low air temperatures (<25th percentile) [−0.18% (95% CI: −0.97%, 0.62%)]. On days with high air pollution (>50th percentile), both heat- and cold-related mortality risks increased. ConclusionOur findings showed that high temperature could modify the effects of air pollution on daily mortality and high air pollution might enhance the air temperature effects.

Temperature-Related Mortality Impacts under Climate Change Scenarios Consistent with the Paris Agreement: A Multi-Country Analysis

Background/Aim: The recent international agreement reached in Paris aims at keeping the increase in global mean temperature (GMT) below 2°C, and it pursues efforts to limit it below 1.5°C. Here we provide evidence on temperature-related direct mortality impacts under these and more extreme climate change scenarios, using a worldwide multi-country dataset. Methods: Two-stage time series analysis using distributed lag non-linear models and multivariate meta-analysis to estimate temperature-mortality relationships for 412 locations within 20 countries in 1985-2012. Future impacts, quantified as attributable risks for non-optimal temperature and for cold and heat separately, were computed under scenarios consistent with 1.5°C, 2°C, 3°C, and 4°C increase in GMT, defined by corresponding 20-year windows identified in temperature series projected along the 21st century using four global climate models. Results: Across different regions of the world, a rise from 1.5°C to 2°C in GMT would generate 0.20%-1.40% increases in heat-related and 0.30%-0.67% decreases in cold-related mortality. Mild temperate areas such as North Europe and Australia would experience a small but significant net decrease (0.28% and 0.47%, respectively), while hotter places such as South Europe and South-East Asia would face a larger significant net increase (0.61% and 0.73%). Changes are close to null in areas characterized by diverse climatic conditions, such as North and South America and East Asia. More extreme scenarios with GMT rising to 3°C-4°C would present more dramatic heat-related impacts, especially in hotter places, with net increases up to 7.10% in some tropical areas. Conclusions: This large worldwide assessment provides evidence of potential health benefits of enforcing mitigation strategies to reduce global warming. Compliance with the limits set by the Paris Agreement (2°C) would prevent dramatic increases in mortality projected in many regions, while more ambitious targets (1.5°C) would be beneficial for hotter tropical areas where a large proportion of world population lives.

Projection of temperature-related mortality due to cardiovascular disease in beijing under different climate change, population, and adaptation scenarios

Human health faces unprecedented challenges caused by climate change. Thus, studies of the effect of temperature change on total mortality have been conducted in numerous countries. However, few of those studies focused on temperature-related mortality due to cardiovascular disease (CVD) or considered future population changes and adaptation to climate change. We present herein a projection of temperature-related mortality due to CVD under different climate change, population, and adaptation scenarios in Beijing, a megacity in China. To this end, 19 global circulation models (GCMs), 3 representative concentration pathways (RCPs), 3 socioeconomic pathways, together with generalized linear models and distributed lag non-linear models, were used to project future temperature-related CVD mortality during periods centered around the years 2050 and 2070. The number of temperature-related CVD deaths in Beijing is projected to increase by 3.5–10.2% under different RCP scenarios compared with that during the baseline period. Using the same GCM, the future daily maximum temperatures projected using the RCP2.6, RCP4.5, and RCP8.5 scenarios showed a gradually increasing trend. When population change is considered, the annual rate of increase in temperature-related CVD deaths was up to fivefold greater than that under no-population-change scenarios. The decrease in the number of cold-related deaths did not compensate for the increase in that of heat-related deaths, leading to a general increase in the number of temperature-related deaths due to CVD in Beijing. In addition, adaptation to climate change may enhance rather than ameliorate the effect of climate change, as the increase in cold-related CVD mortality greater than the decrease in heat-related CVD mortality in the adaptation scenarios will result in an increase in the total number of temperature-related CVD mortalities.

Different Mortality Effects of Extreme Temperature Stress in Three Large City Clusters of Northern and Southern China

Extreme temperature events have affected Chinese city residents more frequently and intensively since the early 2000s, but few studies have identified the impacts of extreme temperature on mortality in different city clusters of China. This study first used a distributed lag, nonlinear model to estimate the county/district-specific effects of extreme temperature on nonaccidental and cardiovascular mortality. The authors then applied a multivariate meta-analysis to pool the estimated effects in order to derive regional temperature–mortality relationship in three large city clusters—the Beijing-Tianjin-Hebei (BTH) region, the Yangtze River Delta (YRD), and the Pearl River Delta (PRD), which represent northern and southern regions. With 0–3 days’ lag, the strongest heat-related mortality effect was observed in the BTH region (with relative risk (RR) of 1.29; 95% confidence interval (CI): 1.13–1.47), followed by the YRD (RR = 1.25; 95% CI: 1.13–1.35) and the PRD (RR = 1.14; 95% CI: 1.01–1.28) areas. With 0–21 days’ lag, the cold effect was pronounced in all city clusters, with the highest extreme cold-related mortality risk found in the PRD area (RR = 2.27; 95% CI: 1.63–3.16), followed by the YRD area (RR = 1.85; 95% CI: 1.56–2.20) and BTH region (RR = 1.33; 95% CI: 0.96–1.83). People in the southern regions tended to be more vulnerable to cold stress, but the northern population was more sensitive to heat stress. By examining the effects of extreme temperature in city clusters of different regions, our findings underline the role of adaptation towards heat and cold, which has important implications for public health policy making and practice.

Biometeorological Assessment of Mortality Related to Extreme Temperatures in Helsinki Region, Finland, 1972-2014.

Climate change is expected to increase heat-related and decrease cold-related mortality. The extent of acclimatization of the population to gradually-changing thermal conditions is not well understood. We aimed to define the relationship between mortality and temperature extremes in different age groups in the Helsinki-Uusimaa hospital district in Southern Finland, and changes in sensitivity of the population to temperature extremes over the period of 1972–2014. Time series of mortality were made stationary with a method that utilizes 365-day Gaussian smoothing, removes trends and seasonality, and gives relative mortality as the result. We used generalized additive models to examine the association of relative mortality to physiologically equivalent temperature (PET) and to air temperature in the 43-year study period and in two 21-year long sub-periods (1972–1992 and 1994–2014). We calculated the mean values of relative mortality in percentile-based categories of thermal indices. Relative mortality increases more in the hot than in the cold tail of the thermal distribution. The increase is strongest among those aged 75 years and older, but is somewhat elevated even among those younger than 65 years. Above the 99th percentile of the PET distribution, the all-aged relative mortality decreased in time from 18.3 to 8.6%. Among those ≥75 years old, the decrease in relative mortality between the sub-periods were found to be above the 90th percentile. The dependence of relative mortality on cold extremes was negligible, except among those ≥75 years old, in the latter period. Thus, heat-related mortality is also remarkable in Finland, but the sensitivity to heat stress has decreased over the decades.

Projected temperature-related deaths in ten large U.S. metropolitan areas under different climate change scenarios

BackgroundThere is an established U-shaped association between daily temperature and mortality. Temperature changes projected through the end of century are expected to lead to higher rates of heat-related mortality but also lower rates of cold-related mortality, such that the net change in temperature-related mortality will depend on location. ObjectivesWe quantified the change in heat-, cold-, and temperature-related mortality rates through the end of the century across 10 large US metropolitan areas. MethodsWe applied location-specific projections of future temperature from over 40 downscaled climate models to exposure-response functions relating daily temperature and mortality in 10 US metropolitan areas to estimate the change in temperature-related mortality rates in 2045–2055 and 2085–2095 compared to 1992–2002, under two greenhouse gas emissions scenarios (RCP 4.5 and 8.5). We further calculated the total number of deaths attributable to temperature in 1997, 2050, and 2090 in each metropolitan area, either assuming constant population or accounting for projected population growth. ResultsIn each of the 10 metropolitan areas, projected future temperatures were associated with lower rates of cold-related deaths and higher rates of heat-related deaths. Under the higher-emission RCP 8.5 scenario, 8 of the 10 metropolitan areas are projected to experience a net increase in annual temperature-related deaths per million people by 2086–2095, ranging from a net increase of 627 (95% empirical confidence interval [eCI]: 239, 1018) deaths per million in Los Angeles to a net decrease of 59 (95% eCI: −485, 314) deaths per million in Boston. Applying these projected temperature-related mortality rates to projected population size underscores the large public health burden of temperature. ConclusionsIncreases in the heat-related death rate are projected to outweigh decreases in the cold-related death rate in 8 out of 10 cities studied under a high emissions scenario. Adhering to a lower greenhouse gas emissions scenario has the potential to substantially reduce future temperature-related mortality.

Mortality of overwintering emerald ash borer (Coleoptera: Buprestidae) associated with an extreme cold event in New York, United States of America

AbstractSevere mortality (93%) of overwintering larvae of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was recorded in March 2016 from green ash, Fraxinus pennsylvanica Marshall (Oleaceae), in Syracuse, New York, United States of America. In contrast, larvae collected from the same area in January exhibited &lt;1% mortality. A strong cold front moved across New York from 13 to 15 February 2016 with temperatures plunging to nearly −40 °C in some areas. In many regions of New York where A. planipennis is established, temperatures dropped well below the reported supercooling point of overwintering larvae. To evaluate whether the extreme cold was linked to extensive mortality of larvae, trees were sampled from four areas that experienced a gradient of minimum temperatures on 14 February 2016. Overwintering mortality varied from ⩽5% to 93% among regions, with lowest survival in the coldest regions. When excised from their galleries, dead larvae were discoloured with brown spots or had black necrotic tissue in the spiracles or foregut. This is the first report of extensive cold-related mortality for this species in North America and highlights the stochastic nature of climatic extremes on invasive species populations.

Socioenvironmental factors associated with heat and cold-related mortality in Vadu HDSS, western India: a population-based case-crossover study

Ambient temperatures (heat and cold) are associated with mortality, but limited research is available about groups most vulnerable to these effects in rural populations. We estimated the effects of heat and cold on daily mortality among different sociodemographic groups in the Vadu HDSS area, western India. We studied all deaths in the Vadu HDSS area during 2004–2013. A conditional logistic regression model in a case-crossover design was used. Separate analyses were carried out for summer and winter season. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for total mortality and population subgroups. Temperature above a threshold of 31 °C was associated with total mortality (OR 1.48, CI = 1.05–2.09) per 1 °C increase in daily mean temperature. Odds ratios were higher among females (OR 1.93; CI = 1.07–3.47), those with low education (OR 1.65; CI = 1.00–2.75), those owing larger agricultural land (OR 2.18; CI = 0.99–4.79), and farmers (OR 1.70; CI = 1.02–2.81). In winter, per 1 °C decrease in mean temperature, OR for total mortality was 1.06 (CI = 1.00–1.12) in lag 0–13 days. High risk of cold-related mortality was observed among people occupied in housework (OR = 1.09; CI = 1.00–1.19). Our study suggests that both heat and cold have an impact on mortality particularly heat, but also, to a smaller degree, cold have an impact. The effects may differ partly by sex, education, and occupation. These findings might have important policy implications in preventing heat and cold effects on particularly vulnerable groups of the rural populations in low and middle-income countries with hot semi-arid climate.

Analysis of the synoptic winter mortality climatology in five regions of England: Searching for evidence of weather signals

Although heat-related mortality has received considerable research attention, the impact of cold weather on public health is less well-developed, probably due to the fact that physiological responses to cold weather can vary substantially among individuals, age groups, diseases etc., depending on a number of behavioral and physiological factors. In the current work we use the classification techniques provided by the COST-733 software to link synoptic circulation patterns with excess cold-related mortality in 5 regions of England. We conclude that, regardless of the classification scheme used, the most hazardous conditions for public health in England are associated with the prevalence of the Easterly type of weather, favoring advection of cold air from continental Europe. It is noteworthy that there has been observed little-to-no regional variation with regards to the classification results among the 5 regions, suggestive of a spatially homogenous response of mortality to the atmospheric patterns identified. In general, the 10 different groupings of days used reveal that excess winter mortality is linked with the lowest daily minimum/maximum temperatures in the area. However it is not uncommon to observe high mortality rates during days with higher, in relative terms, temperatures, when rapidly changing weather results in an increase of mortality. Such a finding confirms the complexity of cold-related mortality and highlights the importance of synoptic climatology in understanding of the phenomenon.

Temporal Changes in Mortality Related to Extreme Temperatures for 15 Cities in Northeast Asia: Adaptation to Heat and Maladaptation to Cold.

Understanding how the temperature-mortality association worldwide changes over time is crucial to addressing questions of human adaptation under climate change. Previous studies investigated the temporal changes in the association over a few discrete time frames or assumed a linear change. Also, most studies focused on attenuation of heat-related mortality and studied the United States or Europe. This research examined continuous temporal changes (potentially nonlinear) in mortality related to extreme temperature (both heat and cold) for 15 cities in Northeast Asia (1972-2009). We used a generalized linear model with splines to simultaneously capture 2 types of nonlinearity: nonlinear association between temperature and mortality and nonlinear change over time in the association. We combined city-specific results to generate country-specific results using Bayesian hierarchical modeling. Cold-related mortality remained roughly constant over decades and slightly increased in the late 2000s, with a larger increase for cardiorespiratory deaths than for deaths from other causes. Heat-related mortality rates have decreased continuously over time, with more substantial decrease in earlier decades, for older populations and for cardiorespiratory deaths. Our findings suggest that future assessment of health effects of climate change should account for the continuous changes in temperature-related health risk and variations by factors such as age, cause of death, and location.

Impacts of cold weather on all-cause and cause-specific mortality in Texas, 1990–2011

Cold weather was estimated to account for more than half of weather-related deaths in the U.S. during 2006–2010. Studies have shown that cold-related excessive mortality is especially relevant with decreasing latitude or in regions with mild winter. However, only limited studies have been conducted in the southern U.S. The purpose of our study is to examine impacts of cold weather on mortality in 12 major Texas Metropolitan Areas (MSAs) for the 22-year period, 1990–2011. Our study used a two-stage approach to examine the cold-mortality association. We first applied distributed lag non-linear models (DLNM) to 12 major MSAs to estimate cold effects for each area. A random effects meta-analysis was then used to estimate pooled effects. Age-stratified and cause-specific mortalities were modeled separately for each MSA. Most of the MSAs were associated with an increased risk in mortality ranging from 0.1% to 5.0% with a 1 °C decrease in temperature below the cold thresholds. Higher increased mortality risks were generally observed in MSAs with higher average daily mean temperatures and lower latitudes. Pooled effect estimate was 1.58% (95% Confidence Interval (CI) [0.81, 2.37]) increase in all-cause mortality risk with a 1 °C decrease in temperature. Cold wave effects in Texas were also examined, and several MSAs along the Texas Gulf Coast showed statistically significant cold wave-mortality associations. Effects of cold on all-cause mortality were highest among people over 75 years old (1.86%, 95% CI [1.09, 2.63]). Pooled estimates for cause-specific mortality were strongest in myocardial infarction (4.30%, 95% CI [1.18, 7.51]), followed by respiratory diseases (3.17%, 95% CI [0.26, 6.17]) and ischemic heart diseases (2.54%, 95% CI [1.08, 4.02]). In conclusion, cold weather generally increases mortality risk significantly in Texas, and the cold effects vary with MSAs, age groups, and cause-specific deaths.

Cold- and heat-related mortality: a cautionary note on current damage functions with net benefits from climate change

Several economic assessments of climate change build on the assumption that reductions of cold-related mortality will overcompensate increases in heat-related mortality at least for moderate levels of global warming. Due to the lack of suitable epidemiological studies with sufficient spatial coverage, many of these assessments rely on one particular dataset: projections of temperature-related mortality in 17 countries published almost 20 years ago. Here, we reanalyse this dataset with a focus on cardiovascular mortality and present evidence for two flaws in the original analysis, which would imply a significant bias towards finding net mortality benefits from climate change: (i) the combination of mortality data for all ages with data specific to the elderly and (ii) the confounding of seasonal effects with direct temperature effects on mortality. This bias appears to be further amplified in the integrated assessment models FUND and ENVISAGE, and related economic assessment tools relying on the same calibration scheme, because heat-related cardiovascular mortality is assumed to affect urban populations only in these models. In an exemplary calculation, we show that while FUND currently projects a net reduction of approximately 380,000 deaths from cardiovascular diseases globally per year at 1 °C of global warming, correcting for the two potential flaws and assuming equal vulnerability of urban and rural populations would result in a net increase of cardiovascular mortality, with approximately 150,000 net additional deaths globally per year. Our findings point to the urgent need of renewing damage functions on temperature-related mortality currently applied in some of the most widely used integrated assessment models.

Temperature and Cardiovascular Mortality Associations in Four Southern Chinese Cities: A Time-Series Study Using a Distributed Lag Non-Linear Model

Few studies on population-specific health effects of extreme temperature on cardiovascular diseases (CVDs) deaths have been conducted in the subtropical and tropical climates of China. We examined the association between extreme temperature and CVD across four cities in China. We performed a two-stage analysis; we generated city-specific estimates using a distributed lag non-linear model (DLNM) and estimated the overall effects by conducting a meta-analysis. Heat thresholds of 29 °C, 29 °C, 29 °C, and 30 °C and cold thresholds of 6 °C, 10 °C, 14 °C, and 15 °C were observed in Hefei, Changsha, Nanning, and Haikou, respectively. The lag periods for heat-related CVD mortality were observed only for 0–2 days, while those of cold-related CVD mortality were observed for 10–15 days. The meta-analysis showed that a 1 °C increase above the city-specific heat threshold was associated with average overall CVD mortality increases of 4.6% (3.0%–6.2%), 6.4% (3.4%–9.4%), and 0.2% (−4.8%–5.2%) for all ages, ≥65 years, and &lt;65 years over a lag period of 0–2 days, respectively. Similarly, a 1 °C decrease below the city-specific cold threshold was associated with average overall CVD mortality increases of 4.2% (3.0%–5.4%), 4.9% (3.5%–6.3%), and 3.1% (1.7%–4.5%), for all ages, ≥65 years, and &lt;65 years over a lag period of 0–15 days, respectively. This work will help to take appropriate measures to reduce temperature-mortality risk in different populations in the subtropical and tropical climates of China.

Impact of energy efficiency interventions in public housing buildings on cold-related mortality: a case-crossover analysis.

Interventions to mitigate fuel poverty and particularly energy efficiency façade retrofitting (EEFR) have demonstrated positive impacts on health but the impacts of EEFR interventions on cold-related mortality have not been studied in depth. We evaluated the impact of EEFR interventions in Barcelona on the association between cold outdoor temperatures and mortality (from all natural causes and from neoplasms, circulatory system and respiratory system causes) from 1986 to 2012. A time-stratified case-crossover analysis was used. Relative risks (RR) for death related to extreme cold (lowest fifth percentile) in the no-intervention and intervention groups were obtained for temperature lag windows covering the day of the death and the previous 20 days (0-2, 3-5, 6-8, 9-11, 12-14, 15-17, 18-20). The statistical significance of the observed changes was evaluated using the RR for the cold temperature-intervention interaction. In men, interventions significantly increased the extreme cold-death association for the lag window 15-17 [interaction RR 2.23, 95% confidence interval (CI) 1.14-4.36]. The impacts were stronger for respiratory system causes and in men aged 75 or older. In women, on lag window 0-2, the extreme cold-death association was not significantly reduced when analysing all natural causes of death (interaction RR 0.46, 95% CI 0.21-1.01), but it was reduced significantly when analysing only deaths from neoplasms, circulatory system and respiratory system causes together. The impacts were stronger in women who died from circulatory system causes, in women with no education and in those aged 75 or older. EEFR interventions had differentiated effects on cold-related mortality in men and women. Differentiated effects were also observed by cause, educational level and age.

Housing Policies and Health Inequalities

A large body of literature shows the link between inadequate housing conditions and poor physical and mental health. The aim of this paper is to summarize the research on the impact of local housing policies on health inequalities, focusing on the issues of access to housing and fuel poverty as studied in the SOPHIE project. Our case studies in Spain showed that people facing housing insecurity, experienced intense levels of mental distress. We found that access to secure and adequate housing can improve the health of these populations, therefore, public policies that address housing instability and their consequences are urgently needed. Housing conditions related to fuel poverty are associated with poorer health and are unevenly distributed across Europe. We found possible positive effects of façade insulation interventions on cold-related mortality in women living in social housing; but not in men. Policies on housing energy efficiency can reduce the health consequences of fuel poverty, but need to be free to users, target the most vulnerable groups and be adaptable to their needs.

What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes.

Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI=0.86-2.54%) per 1°C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI=0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

Socio-environmental factors associated with heat and cold related mortality in Vadu Health and Demographic Surveillance System, western India: A population based case-crossover study

Background: Ambient temperatures are associated with mortality, but limited research is available about groups most vulnerable to these effects in rural populations. We estimated the effects of heat and cold on daily mortality among different socio-demographic groups in the Vadu Health and Demographic Surveillance System (HDSS), western India. Method: We studied all daily deaths in the Vadu HDSS area during 2004-2013. A conditional logistics regression model in a case-crossover design was used. Separate analyses were carried out for summer (above a threshold of 31°C) and winter season temperature. Odd ratios and 95% confidence intervals were estimated for total mortality and population subgroups. Results: Temperature above 31°C was associated with total mortality (OR 1.48; CI=1.05-2.09) per °C increase in daily mean temperature. Odds ratios were higher among females (OR 1.93; CI=1.07-3.47), those with little education (OR 1.65; CI=1.00-2.75), higher socio-economic status (OR 2.18; CI= 0.99-4.79) and farmers (OR 1.70; CI=1.02-2.81). In winter, per °C decrease in temperature, OR for total mortality was 1.06 (CI=1.00-1.12) in lag 0-13 days. High risk of cold-related mortality was observed among people occupied in housework (OR=1.09; CI=1.00-1.19). Conclusion: Our study suggests that both heat and cold have an impact on mortality, and that effects differ partly by sex, education, occupation and socio-economic status. These findings might have important policy implications in preventing heat and cold effects on particularly vulnerable groups of the rural populations in low and middle-income countries with hot semi-arid climate.

Home Energy Efficiency Interventions and Cold-Related Mortality in England, 2000-2010

Introduction: The relationship between home energy efficiency (HEE) investments and health is of interest because of its relevance to policies aimed at tackling excess winter mortality/morbidity an...

Heat and cold related-mortality in France: from time-series studies to prevention

Context: Heat waves are a major health risk in France, as 2015 event recently recalled. Cold-related impacts are still discussed. A better characterization of the temperature-risk association is important to support policy-making. We investigated the heat and cold mortality impacts in 18 French cities between 2000 and 2010. Methods: Cities were selected to represent the diversity of the French climate. A Poisson regression model was fitted in each city, controlling for seasonality, long-term trend, day of the week, holiday, PM10 and ozone. The temperature-mortality associations were estimated with a distributed lag non-linear model considering daily mean temperature with lags up to 21 days as the exposure variable. City specific results were pooled in a multivariate meta-analysis. A meta-regression that included environmental, demographic and socioeconomic variables was performed. Results: Cold and warm temperatures have a significant impact on mortality in France, but their effects present contrasted temporal dynamics. After exposure to extremely warm temperatures (percentile P99.9 of the temperatures distribution), an increase in mortality of 80% was observed during the first three days compared to the P50 mortality used as reference. At temperatures between P99 and P90, we observed a rapid increase in mortality during the first 3 days, followed by a moderate harvesting effect. Exposure to very cold (P0.1) and cold temperature (P1) results in a low mortality impact, but maintained over 21 days. The relative risk (RR) cumulated over 21days was 1.96 [1.59:2.42] for extreme heat (P99.9 versus P50) and 1.38 [1.26:1.51] for extreme cold (P0.1 versus P50). RR were modified by population density and percent of low-income inhabitants. Discussion: These results support the setting of an immediate public health response for heat, and longer term prevention for cold. They call for strengthening heat-related adaptation in the context of climate change.

Association of cold temperature and mortality and effect modification in the subtropical plateau monsoon climate of Yuxi, China

BackgroundConsistent evidence has shown excess mortality associated with cold temperature, but some important details of the cold–mortality association (e.g. slope and threshold) have not been adequately investigated and few studies focused on the cold effect in high-altitude areas of developing countries. We attempted to quantify the cold effect on mortality, identify the details, and evaluate effect modification in the distinct subtropical plateau monsoon climate of Yuxi, a high plateau region in southwest China. MethodsFrom daily mortality and meteorological data during 2009–2014, we used a quasi-Poisson model combined with a “natural cubic spline–natural cubic spline” distributed lag non-linear model to estimate the temperature–mortality relationship and then a simpler “hockey-stick” model to investigate the cold effect and details. ResultsCold temperature was associated with increased mortality, and the relative risk of cold effect (1st relative to 10th temperature percentile) on non-accidental, cardiovascular, and respiratory mortality for lag 0–21 days was 1.40 (95% confidence interval: 1.19–1.66), 1.61 (1.28–2.02), and 1.13 (0.78–1.64), respectively. A 1°C decrease below a cold threshold of 9.1°C (8th percentile) for lags 0–21 was associated with a 7.35% (3.75–11.09%) increase in non-accidental mortality. The cold–mortality association was not significantly affected by cause-specific mortality, gender, age, marital status, ethnicity, occupation, or previous history of hypertension. ConclusionsThere is an adverse impact of cold on mortality in Yuxi, China, and a temperature of 9.1°C is an important cut-off for cold-related mortality for residents.