Short-term association between air temperature and mortality in seven cities in Norway: A time series analysis.

BACKGROUND: The association between ambient air temperature and mortality has not been assessed in Norway. This study aimed to quantify for seven Norwegian cities (Oslo, Bergen, Stavanger, Drammen, Fredrikstad, Trondheim and Tromsø) the non-accidental, cardiovascular and respiratory diseases mortality burden due to non-optimal ambient temperatures. METHODS: We used a historical daily dataset (1996-2018) to perform city-specific analyses with a distributed lag non-linear model with 14 days of lag, and pooled results in a multivariate meta-regression. We calculated attributable deaths for heat and cold, defined as days with temperatures above and below the city-specific optimum temperature. We further divided temperatures into moderate and extreme using cut-offs at the 1st and 99th percentiles. RESULTS: We observed that 5.3% (95% confidence interval (CI) 2.0-8.3) of the non-accidental related deaths, 11.8% (95% CI 6.4-16.4) of the cardiovascular and 5.9% (95% CI -4.0 to 14.3) of the respiratory were attributable to non-optimal temperatures. Notable variations were found between cities and subgroups stratified by sex and age. The mortality burden related to cold dominated in all three health outcomes (5.1%, 2.0-8.1, 11.4%, 6.0-15.4, and 5.1%, -5.5 to 13.8 respectively). Heat had a more pronounced effect on the burden of respiratory deaths (0.9%, 0.2-1.0). Extreme cold accounted for 0.2% of non-accidental deaths and 0.3% of cardiovascular and respiratory deaths, while extreme heat contributed to 0.2% of non-accidental and to 0.3% of respiratory deaths. CONCLUSIONS: Most of the burden could be attributed to the contribution of moderate cold. This evidence has significant implications for enhancing public-health policies to better address health consequences in the Norwegian setting.

Temperature modifies the association between air pollution and respiratory disease mortality in Cape Town, South Africa.

The aim of this 10-year study was to investigate whether and how temperature modifies the association between daily ambient PM10, NO2, SO2 air pollution and daily respiratory disease mortality in Cape Town. A time-stratified case-crossover epidemiological design was applied. Susceptibility by sex and age groups (15-64 years and ≥65 years) was also investigated. On days with medium Tapp levels, NO2 displayed a stronger association with respiratory mortality than PM10 or SO2. Females appeared to be more susceptible to NO2 at medium Tapp levels to males. The 15-64-year-old age group seemed to be more vulnerable to NO2 and PM10 at medium Tapp levels compared to the elderly (≥65 years). At high Tapp levels, females were more susceptible to PM10. The 15-64-year-old group were more vulnerable to NO2 and SO2. The results can be used in present-day early warning systems and in risk assessments to estimate the impact of increased air pollution and temperature.

Acute effect of fine particulate matter and respiratory mortality in Changsha, China: a time-series analysis.

BACKGROUND: Previous studies have confirmed that exposure to fine particulate matter (PM2.5) is associated with respiratory disease mortality. However, due to the differences in PM2.5 concentration, composition and population susceptibility within different regions, the estimates of the association between PM2.5 concentration and mortality are different. Moreover, few studies have examined the potential hazard of excessive PM2.5 exposure in terms of respiratory disease mortality. METHODS: Daily recorded data on meteorological indices, environmental pollutants, and causes of death data in Changsha from January 2015 to December 2018 were obtained. The potential relationship between PM2.5 concentrations and respiratory disease mortality was determined using distributed lag nonlinear model (DLNM), which includes the relative risk (RR) and cumulative relative risk (CRR) of the lagged effect. The synergistic effects of other air pollutants were also considered. RESULTS: A total of 8,825 cases of respiratory disease mortality occurred in Changsha between 2015 and 2018. The acute effect of PM2.5 concentration was associated with an increased risk of respiratory disease mortality. Regarding the lag specific effect, a 10 µg/m3 increase in PM2.5 concentration on respiratory disease mortality was statistically significant at lag day 0 and lag day 7 with a relative risk of 1.019 (95% CI 1.007- 1.031) and 1.013(95%CI: 1.002-1.024). As for the cumulative lag effect, a 4-day moving average of PM2.5 concentrations was significantly associated with a cumulative relative risk of 1.027 (95%CI: 1.011-1.031). The single-day lag effect and cumulative 4-day lag effect for male individuals were more significant than those observed in females. The effect of PM2.5 concentrations and respiratory disease mortality remained statistically significant in the multi-pollutant models (SO2, NO2, and O3). A higher risk was observed in the cold season than in the warm season. CONCLUSIONS: Our findings show a potential association between exposure to PM2.5 concentration and respiratory disease mortality in Changsha, with male individuals observed to have particularly higher risk.

The impact of Long-Term PM2.5 constituents and their sources on specific causes of death in a US Medicare cohort.

BACKGROUND: Our understanding of the impact of long-term exposures to PM2.5 constituents and sources on mortality is limited. OBJECTIVES: To examine associations between long-term exposures to PM2.5 constituents and sources and cause-specific mortality in US older adults. METHODS: We obtained demographic and mortality data for 15.4 million Medicare beneficiaries living within the conterminous United States (US) between 2000 and 2008. We assessed PM2.5 constituents exposures for each beneficiary and used factor analysis and residual-based methods to characterize PM2.5 sources and mixtures, respectively. In age-, sex-, race- and site- stratified Cox proportional hazard models adjusted for neighborhood socio-economic status (SES), we assessed associations of individual PM2.5 constituents, sources, and mixtures and cause-specific mortality and examined modification of these associations by participant demographics and location of residence. We assessed the robustness of our findings to additional adjustment for behavioral risk factors and to alternate exposure definitions and exposure windows. RESULTS: Hazard ratios (HR) were highest for all causes of death, except COPD, for PM2.5 constituents and the coal combustion-related PM2.5 components, with no evidence of confounding by behavioral covariates. We further found Pb and metal-related PM2.5 components to be significantly associated with increased HR of all causes of death, except COPD and lung cancer mortality, and nitrate (NO3-) and silicon (Si) and associated source-related PM2.5 components (traffic and soil, respectively) to be significantly associated with increased all-cause, CVD, respiratory and all cancer-related mortality HR. Associations for other examined constituents and mortality were inconsistent or largely null. Our analyses of mixtures were generally consistent with these findings. Mortality HRs were greatest for minority, especially Black, low-income urban, younger, and male beneficiaries. DISCUSSION: PM2.5 components related to coal combustion, traffic, and to a lesser extent, soil were strongly associated with mortality from CVD, respiratory disease, and cancer.

The impact of long-term PM2.5 exposure on specific causes of death: exposure-response curves and effect modification among 53 million U.S. Medicare beneficiaries.

BACKGROUND: The shape of the exposure-response curve for long-term ambient fine particulate (PM2.5) exposure and cause-specific mortality is poorly understood, especially for rural populations and underrepresented minorities. METHODS: We used hybrid machine learning and Cox proportional hazard models to assess the association of long-term PM2.5 exposures on specific causes of death for 53 million U.S. Medicare beneficiaries (aged ≥65) from 2000 to 2008. Models included strata for age, sex, race, and ZIP code and controlled for neighborhood socio-economic status (SES) in our main analyses, with approximately 4 billion person-months of follow-up, and additionally for warm season average of 1-h daily maximum ozone exposures in a sensitivity analysis. The impact of non-traffic PM2.5 on mortality was examined using two stage models of PM2.5 and nitrogen dioxide (NO2). RESULTS: A 10 µg /m3 increase in 12-month average PM2.5 prior to death was associated with a 5% increase in all-cause mortality, as well as an 8.8, 5.6, and 2.5% increase in all cardiovascular disease (CVD)-, all respiratory-, and all cancer deaths, respectively, in age, gender, race, ZIP code, and SES-adjusted models. PM2.5 exposures, however, were not associated with lung cancer mortality. Results were not sensitive to control for ozone exposures. PM2.5-mortality associations for CVD- and respiratory-related causes were positive and significant for beneficiaries irrespective of their sex, race, age, SES and urbanicity, with no evidence of a lower threshold for response or of lower Risk Ratios (RRs) at low PM2.5 levels. Associations between PM2.5 and CVD and respiratory mortality were linear and were higher for younger, Black and urban beneficiaries, but were largely similar by SES. Risks associated with non-traffic PM2.5 were lower than that for all PM2.5 and were null for respiratory and lung cancer-related deaths. CONCLUSIONS: PM2.5 was associated with mortality from CVD, respiratory, and all cancer, but not lung cancer. PM2.5-associated risks of CVD and respiratory mortality were similar across PM2.5 levels, with no evidence of a threshold. Blacks, urban, and younger beneficiaries were most vulnerable to the long-term impacts of PM2.5 on mortality.

Circulating 25-hydroxyvitamin D concentration and cause-specific mortality in the Melbourne Collaborative Cohort Study.

Vitamin D deficiency is associated with higher all-cause mortality, but associations with specific causes of death are unclear. We investigated the association between circulating 25-hydroxyvitamin D (25(OH)D) concentration and cause-specific mortality using a case-cohort study within the Melbourne Collaborative Cohort Study (MCCS). Eligibility for the case-cohort study was restricted to participants with baseline dried blood spot samples and no pre-baseline diagnosis of cancer. These analyses included participants who died (n = 2307) during a mean follow-up of 14 years and a sex-stratified random sample of eligible cohort participants ('subcohort', n = 2923). Concentration of 25(OH)D was measured using liquid chromatography-tandem mass spectrometry. Cox regression, with Barlow weights and robust standard errors to account for the case-cohort design, was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for cause-specific mortality in relation to 25(OH)D concentration with adjustment for confounders. Circulating 25(OH)D concentration was inversely associated with risk of death due to cancer (HR per 25 nmol/L increment = 0.88, 95 % CI 0.78-0.99), particularly colorectal cancer (HR = 0.75, 95 % CI 0.57-0.99). Higher 25(OH)D concentrations were also associated with a lower risk of death due to diseases of the respiratory system (HR = 0.62, 95 % CI 0.43-0.88), particularly chronic obstructive pulmonary disease (HR = 0.53, 95 % CI 0.30-0.94), and diseases of the digestive system (HR = 0.44, 95 % CI 0.26-0.76). Estimates for diabetes mortality (HR = 0.64, 95 % CI 0.33-1.26) and cardiovascular disease mortality (HR = 0.90, 95 % CI 0.76-1.07) lacked precision. The findings suggest that vitamin D might be important for preventing death due to some cancers, respiratory diseases, and digestive diseases.

Periodontitis increases the risk of respiratory disease mortality in older patients.

Evidence for an association between periodontitis and respiratory disease in the older patients is limited. Additionally, little information exists regarding the role of potential effect modifiers. The aim of this study is to examine whether periodontitis increases the risk of respiratory disease mortality in older patients. Between January 2010 and December 2014, 1385 patients aged 75 years and above who underwent radiographic examination in the largest dental hospital in Shanghai, China were included in this retrospective cohort study. The dental examination was made with the panoramic radiographs. Demographic information and comorbid health conditions were collected from local health authorities. Participant follow up was continued until either the occurrence of mortality, or the end of the study on December 31, 2018. Cox proportional hazards regression and competing risk hazard models were performed to examine the association between periodontitis and respiratory disease mortality. We found that periodontitis was associated with total respiratory disease mortality. Compared with healthy participants, the hazards ratio and 95% confidence interval for total respiratory disease mortality in patients with severe periodontitis was 2.72(1.04,7.11) after adjusting for relevant confounding variables. With increasing severity of periodontitis, risks for chronic obstructive pulmonary disease (COPD) mortality also increased significantly (P = .038). Smokers and participants with body mass index (BMI) < 25 kg/m2 were at increased risk. Loss of teeth was not associated with either total respiratory disease or COPD mortality. Although the present study cannot ascertain causal association, it provides substantial evidence that poor periodontal health is associated with respiratory disease in the older patients, particularly in smokers and patients with BMI < 25 kg/m2.

Vitamin D Status and Mortality: A Systematic Review of Observational Studies.

Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality, but it is unclear whether this is explained by reverse causation, and if there are specific causes of death for which vitamin D might be important. We conducted a systematic review of observational studies investigating associations between circulating 25-hydroxyvitamin D (25(OH)D) concentration and all-cause or cause-specific mortality in generally healthy populations. Relevant studies were identified using PubMed and EMBASE searches. After screening 722 unique records and removing those that were ineligible, 84 articles were included in this review. The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality. This association appeared to be non-linear, with progressively lower mortality with increasing 25(OH)D up to a point, beyond which there was no further decrease. There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases, while for cardiovascular mortality, there is weak evidence of an association in observational studies, which is not supported by the data from intervention or Mendelian randomization studies. The relationship between vitamin D status and other causes of death remains uncertain due to limited data. Larger long-term studies are required to clarify these associations.

Long-Term PM2.5 Exposure and Respiratory, Cancer, and Cardiovascular Mortality in Older US Adults.

The impact of chronic exposure to fine particulate matter (particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (PM2.5)) on respiratory disease and lung cancer mortality is poorly understood. In a cohort of 18.9 million Medicare beneficiaries (4.2 million deaths) living across the conterminous United States between 2000 and 2008, we examined the association between chronic PM2.5 exposure and cause-specific mortality. We evaluated confounding through adjustment for neighborhood behavioral covariates and decomposition of PM2.5 into 2 spatiotemporal scales. We found significantly positive associations of 12-month moving average PM2.5 exposures (per 10-µg/m3 increase) with respiratory, chronic obstructive pulmonary disease, and pneumonia mortality, with risk ratios ranging from 1.10 to 1.24. We also found significant PM2.5-associated elevated risks for cardiovascular and lung cancer mortality. Risk ratios generally increased with longer moving averages; for example, an elevation in 60-month moving average PM2.5 exposures was linked to 1.33 times the lung cancer mortality risk (95% confidence interval: 1.24, 1.40), as compared with 1.13 (95% confidence interval: 1.11, 1.15) for 12-month moving average exposures. Observed associations were robust in multivariable models, although evidence of unmeasured confounding remained. In this large cohort of US elderly, we provide important new evidence that long-term PM2.5 exposure is significantly related to increased mortality from respiratory disease, lung cancer, and cardiovascular disease.

Ozone, Fine Particulate Matter, and Chronic Lower Respiratory Disease Mortality in the United States.

RATIONALE: Short-term effects of air pollution exposure on respiratory disease mortality are well established. However, few studies have examined the effects of long-term exposure, and among those that have, results are inconsistent. OBJECTIVES: To evaluate long-term association between ambient ozone, fine particulate matter (PM2.5, particles with an aerodynamic diameter of 2.5 µm or less), and chronic lower respiratory disease (CLRD) mortality in the contiguous United States. METHODS: We fit Bayesian hierarchical spatial Poisson models, adjusting for five county-level covariates (percentage of adults aged ≥65 years, poverty, lifetime smoking, obesity, and temperature), with random effects at state and county levels to account for spatial heterogeneity and spatial dependence. MEASUREMENTS AND MAIN RESULTS: We derived county-level average daily concentration levels for ambient ozone and PM2.5 for 2001-2008 from the U.S. Environmental Protection Agency's down-scaled estimates and obtained 2007-2008 CLRD deaths from the National Center for Health Statistics. Exposure to ambient ozone was associated with an increased rate of CLRD deaths, with a rate ratio of 1.05 (95% credible interval, 1.01-1.09) per 5-ppb increase in ozone; the association between ambient PM2.5 and CLRD mortality was positive but statistically insignificant (rate ratio, 1.07; 95% credible interval, 0.99-1.14). CONCLUSIONS: This study links air pollution exposure data with CLRD mortality for all 3,109 contiguous U.S. counties. Ambient ozone may be associated with an increased rate of death from CLRD in the contiguous United States. Although we adjusted for selected county-level covariates and unobserved influences through Bayesian hierarchical spatial modeling, the possibility of ecologic bias remains.

Association of fine particles with respiratory disease mortality: a meta-analysis.

Short-time exposure to high levels of fine particles (particulate matter with an aerodynamic diameter≤2.5 µm; PM2.5) may trigger respiratory disease, but this association has not been determined. The objective of this study was to evaluate and quantify the short-time exposure to fine particles on respiratory disease mortality. Published articles were obtained from electronic databases and a validity assessment was used. The meta-analysis was conducted with the incorporation of good-quality studies. After applying the inclusion criteria, 9 articles were included in the study. The methodological qualities of the published studies were good, and every study achieved a score of 3. Fine particles were significantly associated with an increase in respiratory mortality risk (for every 10 µg/m3 increment, rate difference [RD]=1.32%, 95% confidence interval [CI]: 0.95%-1.68%; p=.000). These findings indicate that short-time exposure to fine particles could increase the risk of respiratory disease mortality.