Health Effects In Population Research Articles

Synthetically lagged models

Epidemiologic studies often report health risk due to short-term air pollution exposure through examination of lagged association, expressing manifestation of population health effects over time. We develop a new approach to the problem of lagged manifestation of air pollution exposure: synthetically lagged models. This approach also generalizes to other lagged time series regression models.

Population health effects and health-related costs of extreme temperatures: Comprehensive evidence from Germany

This study assesses the short and medium-term impact of extreme temperatures on population health and health-related costs in Germany. For 1999 to 2008, we link the universe of 170 million hospital admissions and all 8 million deaths with weather and pollution data at the day-county level. Extreme heat significantly and immediately increases hospitalizations and deaths. This finding holds irrespective of whether we employ econometric models that are standard in economics or models that are standard in epidemiology; we compare and discuss both approaches. We find evidence for partial “harvesting.” At the end of a 30-day window, the immediate health effects are, on average, one quarter lower, but this reduction is primarily evident for cardiovascular and neoplastic diseases. Moreover, aggregating at the yearly level reduces the effect size by more than 90 percent. The health-related economic costs accumulate up to €5 million per 10 million population per hot day with maximum temperatures above 30 °C (86 °F).

Space-time PM2.5 mapping in the severe haze region of Jing-Jin-Ji (China) using a synthetic approach

Long- and short-term exposure to PM2.5 is of great concern in China due to its adverse population health effects. Characteristic of the severity of the situation in China is that in the Jing-Jin-Ji region considered in this work a total of 2725 excess deaths have been attributed to short-term PM2.5 exposure during the period January 10–31, 2013. Technically, the processing of large space-time PM2.5 datasets and the mapping of the space-time distribution of PM2.5 concentrations often constitute high-cost projects. To address this situation, we propose a synthetic modeling framework based on the integration of (a) the Bayesian maximum entropy method that assimilates auxiliary information from land-use regression and artificial neural network (ANN) model outputs based on PM2.5 monitoring, satellite remote sensing data, land use and geographical records, with (b) a space-time projection technique that transforms the PM2.5 concentration values from the original spatiotemporal domain onto a spatial domain that moves along the direction of the PM2.5 velocity spread. An interesting methodological feature of the synthetic approach is that its components (methods or models) are complementary, i.e., one component can compensate for the occasional limitations of another component. Insight is gained in terms of a PM2.5 case study covering the severe haze Jing-Jin-Ji region during October 1–31, 2015. The proposed synthetic approach explicitly accounted for physical space-time dependencies of the PM2.5 distribution. Moreover, the assimilation of auxiliary information and the dimensionality reduction achieved by the synthetic approach produced rather impressive results: It generated PM2.5 concentration maps with low estimation uncertainty (even at counties and villages far away from the monitoring stations, whereas during the haze periods the uncertainty reduction was over 50% compared to standard PM2.5 mapping techniques); and it also proved to be computationally very efficient (the reduction in computational time was over 20% compared to standard mapping techniques).

Potential geography and productivity of “Hass” avocado crops in Colombia estimated by ecological niche modeling

Abstract Variation in environmental suitability across the geographic range of a species is common, with consequences for population health and production. Ecological niche modeling (ENM) is an effort to estimate environmental requirements of species based on associations between known geographic occurrences and environmental conditions at those sites, to allow estimation of the potential distribution of the species. We developed an ENM for Hass avocado production fields in Colombia, in which we related the distribution of avocado production lots to environmental information derived from multitemporal MODIS satellite imagery and digital elevation models. Models were calibrated using maximum entropy approaches, using likelihood and information content metrics to optimize model selection; model performance was measured in terms of omission error with respect to independent testing data. Two models were selected that presented best combinations of high information content, significance, and performance based on lower values of Akaike Information Criterion (AICc), partial receiver operating characteristic (partialROC), and low omission of independent testing data records. Suitability values from those models were compared to Hass avocado production; models were able to identify both novel areas with potential for cultivation, and sites where this crop has been planted in relatively unsuitable areas. A statistically significant positive relationship existed between suitability values from the models and avocado production, with different relationships for three technological levels. ENM approaches thus offer a useful and novel tool for exploring and designing sustainable agriculture systems, identifying areas with environmental potential in Colombia and currently not planted with Hass avocado.

Human Exposure Assessment of Airborne Pollutants for Residents in Gwangyang City Near Industrial Plants (I)

The object of this study is to analyze metabolites of environmental chemicals and to identify possible health hazards to obtain reliable levels of exposure in Gwangyang city in the vicinity of a refinery and steel industrial complex in the year 2011-2012. Participant age in each gender was significantly >59 years comprising more than 90% of the total participants and female participants were almost double males. Target metabolites included 21 chemicals of 3 heavy metals, 4 polycyclic aromatic hydrocarbons (PAHs), 7 volatile organic compounds (VOCs), 5 phthalates and creatinine. We found some interesting points of comparison. The geometric mean values of metabolites in control area were similar to or slightly higher overall than those in the exposed area. Some metabolites, such as urinary (U)-Hg and organic metabolites like VOCs, PAHs and phthalates, significantly showed higher concentrations in the control area. Whilst their highest (max.) values for three metabolites (U-m-methylhippuric acid (MHA), U-p-MHA and U-monobenzyl phthalate) in the exposed was always higher than the control. Moreover U-Cadmium, U-2-Naphtol and U-ttmuconic acid (MA) in the exposed area far exceeded the national average and average of 50+ age group. Interesting gender-specific differences in three VOC metabolites (U-t,t-MA, U-hippuric acid (HA), U-mandelic acid (MA) (female specific, females>males) and blood (B)-lead (Pb) (male specific, males>females) were seen, and were always higher in males or females in both areas. Accordingly, the present study indicates that heavy metals and VOCs appear to be the most noteworthy pollutants that may cause adverse health effects in the human population near Gwangyang city. In conclusion, observed metabolite levels did not exceed health-based reference values and/or guidelines available. Nevertheless, continuing biomonitoring surveillance is necessary to watch on hazardous air pollutants (HAPs) to protect public health in industrial sites.

Early life exposure to ethinylestradiol enhances subsequent responses to environmental estrogens measured in a novel transgenic zebrafish

Estrogen plays fundamental roles in a range of developmental processes and exposure to estrogen mimicking chemicals has been associated with various adverse health effects in both wildlife and human populations. Estrogenic chemicals are found commonly as mixtures in the environment and can have additive effects, however risk analysis is typically conducted for single-chemicals with little, or no, consideration given for an animal’s exposure history. Here we developed a transgenic zebrafish with a photoconvertable fluorophore (Kaede, green to red on UV light exposure) in a skin pigment-free mutant element (ERE)-Kaede-Casper model and applied it to quantify tissue-specific fluorescence biosensor responses for combinations of estrogen exposures during early life using fluorescence microscopy and image analysis. We identify windows of tissue-specific sensitivity to ethinylestradiol (EE2) for exposure during early-life (0–5 dpf) and illustrate that exposure to estrogen (EE2) during 0–48 hpf enhances responsiveness (sensitivity) to different environmental estrogens (EE2, genistein and bisphenol A) for subsequent exposures during development. Our findings illustrate the importance of an organism’s stage of development and estrogen exposure history for assessments on, and possible health risks associated with, estrogen exposure.

The Montreal heat response plan: evaluation of its implementation towards healthcare professionals and vulnerable populations.

Since 2004, the Montreal heat response plan (MHRP) has been developed and implemented on the Island of Montreal to reduce heat-related health effects in the general population. In this paper, we aimed to assess the barriers and facilitators to implementation of the MHRP and evaluate the awareness of key elements of the plan by healthcare professionals and individuals from vulnerable populations. Data were gathered from monitoring reports and a questionnaire administered to managers of healthcare institutions and healthcare workers in Montreal-area health and social services institutions. Individual interviews and focus groups with healthcare workers and with individuals with schizophrenia or suffering from drug or alcohol dependencies were performed. Data were categorized according to predefined subthemes. Coding matrices were then used to determine the most frequently occurring elements in the subthemes. Our results indicate that actions are progressively implemented each year in the healthcare network. Intensification of surveillance for signs of heat-related illness is the most frequently reported measure. Identification and prioritization of clientele and homecare patients are identified as a challenge, as is ensuring the availability of sufficient personnel during a heat wave. Analysis of practice and awareness in healthcare professionals reveals that preventive measures are known and applied by the personnel. Individuals from vulnerable population groups were not uniformly aware of preventive measures, and consequently, variability was observed in their application. The framework proposed in this study revealed valuable information that can be useful to improve plans aimed at reducing heat-related health effects in the population.

The Effect of Shorter Treatment Regimens for Hepatitis C on Population Health and Under Fixed Budgets.

BackgroundDirect acting antiviral hepatitis C virus (HCV) therapies are highly effective but costly. Wider adoption of an 8-week ledipasvir/sofosbuvir treatment regimen could result in significant savings, but may be less efficacious compared with a 12-week regimen. We evaluated outcomes under a constrained budget and cost-effectiveness of 8 vs 12 weeks of therapy in treatment-naïve, noncirrhotic, genotype 1 HCV-infected black and nonblack individuals and considered scenarios of IL28B and NS5A resistance testing to determine treatment duration in sensitivity analyses.MethodsWe developed a decision tree to use in conjunction with Monte Carlo simulation to investigate the cost-effectiveness of recommended treatment durations and the population health effect of these strategies given a constrained budget. Outcomes included the total number of individuals treated and attaining sustained virologic response (SVR) given a constrained budget and incremental cost-effectiveness ratios.ResultsWe found that treating eligible (treatment-naïve, noncirrhotic, HCV-RNA <6 million copies) individuals with 8 weeks rather than 12 weeks of therapy was cost-effective and allowed for 50% more individuals to attain SVR given a constrained budget among both black and nonblack individuals, and our results suggested that NS5A resistance testing is cost-effective.ConclusionsEight-week therapy provides good value, and wider adoption of shorter treatment could allow more individuals to attain SVR on the population level given a constrained budget. This analysis provides an evidence base to justify movement of the 8-week regimen to the preferred regimen list for appropriate patients in the HCV treatment guidelines and suggests expanding that recommendation to black patients in settings where cost and relapse trade-offs are considered.

Confounding by ill health in the observed association between BMI and mortality: evidence from the HUNT Study using offspring BMI as an instrument

BackgroundThe observational association between mortality and body mass index (BMI) is U-shaped, leading to highly publicized suggestions that moderate overweight is beneficial to health. However, it is unclear whether elevated mortality is caused by low BMI or if the association is confounded, for example by concurrent ill health.MethodsUsing HUNT, a Norwegian prospective study, 32 452 mother-offspring and 27 747 father-offspring pairs were followed up to 2009. Conventional hazard ratios for parental mortality per standard deviation of BMI were estimated using Cox regression adjusted for behavioural and socioeconomic factors. To estimate hazard ratios with reduced susceptibility to confounding, particularly from concurrent ill health, the BMI of parents’ offspring was used as an instrumental variable for parents’ own BMI. The shape of mortality-BMI associations was assessed using cubic splines.ResultsThere were 18 365 parental deaths during follow-up. Conventional associations of mortality from all-causes, cardiovascular disease and cancer with parents’ own BMI were substantially nonlinear, with elevated mortality at both extremes and minima at 21–25 kg m−2. Equivalent associations with offspring BMI were positive and there was no evidence of elevated parental mortality at low offspring BMI. The linear instrumental variable hazard ratio for all-cause mortality per standard deviation increase in BMI was 1.18 (95% confidence interval: 1.10, 1.26), compared with 1.05 (1.03, 1.06) in the conventional analysis.ConclusionsElevated mortality rates at high BMI appear causal, whereas excess mortality at low BMI is likely exaggerated by confounding by factors including concurrent ill health. Conventional studies probably underestimate the adverse population health consequences of overweight.

Health Effects Related to Wind Turbine Sound, Including Low-Frequency Sound and Infrasound

A narrative review of observational and experimental studies was conducted to assess the association between exposure to wind turbine sound and its components and health effects in the general population. Literature databases Scopus, Medline and Embase and additional bibliographic sources such as reference sections of key publications and journal databases were systematically searched for peer-reviewed studies published from 2009 to 2017. For the period until early 2015 only reviews were included, while for the period between January 2015 and January 2017 all relevant publications were screened. Ten reviews and 22 studies met the inclusion criteria. Most studies examined subjective annoyance as the primary outcome, indicating an association between exposure levels and the percentage highly annoyed. Sound from wind turbines leads to a higher percentage of highly annoyed when compared to other sound sources. Annoyance due to aspects, like shadow flicker, the visual (in) appropriateness in the landscape and blinking lights, can add to the noise annoyance. There is no evidence of a specific effect of the low-frequency component nor of infrasound. There are indications that the rhythmic pressure pulses on a building can lead to additional annoyance indoors. Personal characteristics such as noise sensitivity, privacy issues and social acceptance, benefits and attitudes, the local situation and the conditions of planning a wind farm also play a role in reported annoyance. Less data are available to evaluate the effects of wind turbines on sleep and long-term health effects. Sleep disturbance as well as other health effects in the vicinity of wind turbines was found to be related to annoyance, rather than directly to exposure.

Co-occurrence of citrinin and ochratoxin A in rice in Asia and its implications for human health.

Citrinin (CIT) and ochratoxin A (OTA) are nephrotoxic mycotoxins, produced by several Aspergillus and Penicillium species and their co-occurrence in rice may cause health effects in humans. Rice is an important food crop worldwide and is a major staple food in Asia which may be invaded by CIT and OTA producing fungal spores in the field, during harvest and storage. Humans are exposed to these mycotoxins through ingestion of contaminated rice and other food commodities. Yet, data on the combined presence to these food contaminants are still insufficient to estimate human exposure in Asia. This review describes the prevalence of CIT and OTA in rice in Asia and its implications on human health, which may help in establishing and carrying out proper management strategies against mould development on rice. From the health point of view, combined exposition of CIT and OTA should be a public concern as both are nephrotoxic and long-term exposure can pose detrimental health effects. Thus, it is necessary for local farmers and food factories to implement strict measures and to improve methods for rice preservation during the distribution to consumers, particularly in the markets. Moreover, regular surveys for CIT and OTA occurrence in rice and human biomonitoring are recommended to reduce the health effects in Asian population. © 2017 Society of Chemical Industry.

Occurrence and dietary exposure assessment of PFOS and PFOA in cultured Trachinotus ovatus in China

ABSTRACTIn this study, investigation was conducted into concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in Chinese farmed Trachinotus ovatus between 2014 and 2015 using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method. The tissue distribution (muscle, skin, liver, kidney and gill) in Trachinotus ovatus was also assessed. The detection frequencies of PFOS and PFOA in fish were 92% and 3%, respectively, and the mean concentrations were 0.392 and 0.015 μg/kg wet weight. The analysis of PFOS distribution in different tissues in Trachinotus ovatus showed the following trend: skin> gill> kidney> liver> flesh. Results revealeded farmed Trachinotus ovatus in China to generally be contaminated with PFOS. Moreover, the average daily intake for Chinese urban residents calculated on the basis of pollution content was 0.268 ng/kg body weight/d (PFOS) and 0.014 ng/kg body weight /d (PFOA), respectively. Both hazard ratio values were less than 1, indicating that exposure levels of PFOS and PFOA through Trachinotus ovatus consumption may not lead to adverse health effects in the Chinese population.

Association of Electroconvulsive Therapy With Psychiatric Readmissions in US Hospitals

Although electroconvulsive therapy (ECT) is considered the most efficacious treatment available for individuals with severe affective disorders, ECT's availability is limited and declining, suggesting that information about the population-level effects of ECT is needed. To examine whether inpatient treatment with ECT is associated with a reduction in 30-day psychiatric readmission risk in a large, multistate sample of inpatients with severe affective disorders. A quasi-experimental instrumental variables probit model of the association correlation of ECT administration with patient risk of 30-day readmission was estimated using observational, longitudinal data on hospital inpatient discharges from US general hospitals in 9 states. From a population-based sample of 490 252 psychiatric inpatients, a sample was drawn that consisted of 162 691 individuals with a principal diagnosis of major depressive disorder (MDD), bipolar disorder, or schizoaffective disorder. The key instrumental variable used in the analysis was ECT prevalence in the prior calendar year at the treating hospital. To examine whether ECT's association with readmissions was heterogeneous across population subgroups, analyses included interactions of ECT with age group, sex, race/ethnicity, and diagnosis group. The study was conducted from August 27, 2015, to March 7, 2017. Readmission within 30 days of being discharged. Overall, 2486 of the 162 691 inpatients (1.5%) underwent ECT during their index admission. Compared with other inpatients, those who received ECT were older (mean [SD], 56.8 [16.5] vs 45.9 [16.5] years; P < .001) and more likely to be female (65.0% vs 54.2%; P < .001) and white non-Hispanic (85.3% vs 62.1%; P < .001), have MDD diagnoses (63.8% vs 32.0%; P < .001) rather than bipolar disorder (29.0% vs 40.0%; P < .001) or schizoaffective disorder (7.1% vs 28.0%; P < .001), have a comorbid medical condition (31.3% vs 26.6%; P < .001), have private (39.4% vs 21.7%; P < .001) or Medicare (49.2% vs 39.4%; P < .001) insurance coverage, and be located in urban small hospitals (31.2% vs 22.3%; P < .001) or nonurban hospitals (9.0% vs 7.6%; P = .02). Administration of ECT was associated with a reduced 30-day readmission risk among psychiatric inpatients with severe affective disorders from an estimated 12.3% among individuals not administered ECT to 6.6% among individuals administered ECT (risk ratio [RR], 0.54; 95% CI, 0.28-0.81). Significantly larger associations with ECT on readmission risk were found for men compared with women (RR, 0.44; 95% CI, 0.20-0.69 vs 0.58; 95% CI, 0.30-0.88) and for individuals with bipolar disorder (RR, 0.42; 95% CI, 0.17-0.69) and schizoaffective disorder (RR, 0.44; 95% CI, 0.11-0.79) compared with those who had MDD (RR, 0.53; 95% CI, 0.26-0.81). Electroconvulsive therapy may be associated with reduced short-term psychiatric inpatient readmissions among psychiatric inpatients with severe affective disorders. This potential population health effect may be overlooked in US hospitals' current decision making regarding the availability of ECT.

Long-term health consequences of recessions during working years

Economic crises may have severe consequences for population health. We investigate the long-term effects of macroeconomic crises experienced during prime working age (20–50) on health outcomes later in life using SHARE data (Survey of Health Aging and Retirement in Europe) from eleven European countries. Analyses are based on the first two waves of SHARE data collected in 2004 and 2006 (N = 22,886) and retrospective life history data from SHARELIFE collected in 2008 (N = 13,732). Experiencing a severe crisis in which GDP dropped by at least 1% significantly reduces health later in life. Specifically, respondents hit by such a shock rate their subjective health as worse, are more likely to suffer from chronic diseases and mobility limitations, and have lower grip strength. The effects are twice as large among low-educated respondents. A deeper analysis of critical periods in life reveals that respondents’ health is more affected by crises experienced later in the career (between age 41 and 50). The labor market patterns show that these people drop out of the labor force. While men retire early, women are more likely to become home makers. In line with the literature on the negative consequences of retirement on health, this suggests that early retirement in times of economic crises might be detrimental to health.

Long-term effects of total and source-specific particulate air pollution on incident cardiovascular disease in Gothenburg, Sweden

Background and aimsLong-term exposure to air pollution increases cardiopulmonary morbidity and mortality, but it is not clear which components of air pollution are the most harmful, nor which time window of exposure is most relevant. Further studies at low exposure levels have also been called for. We analyzed two Swedish cohorts to investigate the effects of total and source-specific particulate matter (PM) on incident cardiovascular disease for different time windows of exposure. MethodsTwo cohorts initially recruited to study predictors of cardiovascular disease (the PPS cohort and the GOT-MONICA cohort) were followed from 1990 to 2011. We collected data on residential addresses and assigned each individual yearly total and source-specific PM and Nitrogen Oxides (NOx) exposures based on dispersion models. Using multivariable Cox regression models with time-dependent exposure, we studied the association between three different time windows (lag 0, lag 1–5, and exposure at study start) of residential PM and NOx exposure, and incidence of ischemic heart disease, stroke, heart failure and atrial fibrillation. Results and discussionDuring the study period, there were 2266 new-onset cases of ischemic heart disease, 1391 of stroke, 925 of heart failure and 1712 of atrial fibrillation. The majority of cases were in the PPS cohort, where participants were older. Exposure levels during the study period were moderate (median: 13µg/m3 for PM10 and 9µg/m3 for PM2.5), and similar in both cohorts. Road traffic and residential heating were the largest local sources of PM air pollution, and long distance transportation the largest PM source in total. In the PPS cohort, there were positive associations between PM in the last five years and both ischemic heart disease (HR: 1.24 [95% CI: 0.98–1.59] per 10µg/m3 of PM10, and HR: 1.38 [95% CI: 1.08–1.77] per 5µg/m3 of PM2.5) and heart failure. In the GOT-MONICA cohort, there were positive but generally non-significant associations between PM and stroke (HR: 1.48 [95% CI: 0.88–2.49] per 10µg/m3 of PM10, and HR: 1.50 [95% CI: 0.90–2.51] per 5µg/m3 of PM2.5, in the last five years). Effect estimates were stronger for women, non-smokers, and higher socioeconomic classes. Exposure in the last five years seemed to be more strongly associated with outcomes than other exposure time windows. Associations between source-specific PM air pollution and outcomes were mixed and generally weak. High correlations between the main pollutants limited the use of multi-pollutant models. ConclusionsThe main PM air pollutants were associated with ischemic heart disease and stroke (in women) at the relatively low exposure levels in Gothenburg, Sweden. The associations tended to be stronger for women than for men, for non-smokers than for smokers, and for higher socioeconomic classes than for lower. The associations could not be attributed to a specific PM source or type, and differed somewhat between the two cohorts. The results of this study confirm that further efforts to reduce air pollution exposure should be undertaken in Sweden to reduce the negative health effects in the general population.

A scientific tool to address severe haze in Equatorial Asia

BackgroundAcross Indonesia, fires are frequently used to clear forests and manage land for plantations and smallholder farms. The smoke from these fires contain particles that can work their way deep into the lungs and cause premature mortality from cardiovascular disease, stroke, and lung infections, along with many other health effects. These particles can travel hundreds of kilometres downwind, leading to high levels of exposure and adverse health effects in dense population centres across Equatorial Asia. However, accurate prediction of the public health effects from these fires is complicated by links between land use decisions in Indonesia, fire emissions, and transport from source regions to population centres. We aimed to quantify how future scenarios of land management could affect local and regional exposure to smoke concentrations. MethodsWe used satellite observations to quantify the relationships between land management and fires. Using these relationships, we then estimate the cumulative fire emissions of different land management strategies, including (1) “business-as-usual” trends in deforestation and development, (2) increased conversion of forests to oil palm and timber plantations, and (3) successful implementation of the Indonesian Government's moratorium on development and burning in fuel-rich peatlands. We subsequently use the adjoint of the GEOS-Chem chemical transport model to estimate the public health implications of exposure to smoke concentrations from fires in these scenarios. FindingsOur satellite-based analysis shows that most emissions arise from non-forested peatland landscapes with mosaics of degraded lands and agriculture. When combined with three future land management strategies, we find substantial declines in regional smoke concentrations and health impacts when Indonesian peatlands are protected from fires and future development. Results from these initial scenarios show the capabilities of our modelling framework in diverse situations and introduce the capabilities of an online decision support instrument for policymakers. InterpretationWe are now synthesising these efforts to calculate the cumulative health and economic effects over coming decades associated with different land management scenarios in the region. FundingThe Rockefeller Foundation and the Gordon and Betty Moore Foundation through the Health & Ecosystems: Analysis of Linkages (HEAL) programme and the Winslow Foundation.

A system dynamics modelling approach to assess the impact of launching a new nicotine product on population health outcomes

In 2012 the US FDA suggested the use of mathematical models to assess the impact of releasing new nicotine or tobacco products on population health outcomes. A model based on system dynamics methodology was developed to project the potential effects of a new nicotine product at a population level. A model representing traditional smoking populations (never, current and former smokers) and calibrated using historical data was extended to a two-product model by including electronic cigarettes use statuses. Smoking mechanisms, such as product initiation, switching, transition to dual use, and cessation, were represented as flows between smoking statuses (stocks) and the potential effect of smoking renormalisation through a feedback system. Mortality over a 50-year period (2000–2050) was the health outcome of interest, and was compared between two scenarios, with and without e-cigarettes being introduced. The results suggest that by 2050, smoking prevalence in adults was 12.4% in the core model and 9.7% (including dual users) in the counterfactual. Smoking-related mortality was 8.4% and 8.1%, respectively. The results suggested an overall beneficial effect from launching e-cigarettes and that system dynamics could be a useful approach to assess the potential population health effects of nicotine products when epidemiological data are not available.

Investigation of source locations and contributions using an integrated trajectory-source apportionment method with multiple time resolution data

Fine particulate matter (PM2.5) and volatile organic compounds (VOCs) coexist in ambient air and contribute to adverse health effects in human populations. Thus, it is helpful to identify the contributions of air pollutants from different sources in order to design effective control strategies. Nevertheless, different sampling time schedules for VOCs and PM2.5 result in difficulties for conventional receptor modeling. Additionally, a receptor model is unable to link the retrieved factors directly with actual source locations. To address these gaps, this study integrated back-trajectory data into an improved source apportionment model suitable for multiple time resolution data to estimate the locations of the regional transport-related factor. Within six potential source regions (PSRs) outlined by the above method, PSR 5 was suggested the primary one located near the industrial regions in the northeastern China. Constrained model results showed that the source contribution estimates with back trajectories passing over the PSRs were 3 and 9% of the selected VOCs and PM2.5 mass, respectively.

Impact of vaccination on influenza mortality in children

BackgroundInfluenza is a leading cause of respiratory tract infections among children. In Mexico, influenza vaccination was included in the National Immunization Program since 2004. However, the population health effects of the vaccine on children have not been fully described. Thus, we estimated the impact of influenza immunization in terms of mortality associated with this virus among children younger than 5years of age in Mexico. MethodsMortality rates and years of life lost associated with influenza were estimated using national mortality register data for the period 1998–2012. Age-stratified and cause-specific mortality rates were estimated for all-cause, respiratory and cardiovascular events. Influenza-associated mortality was compared between the period prior to introduction of the influenza vaccine as part of the National Immunization Program (1998–2004) and the period thereafter (2004–2012). ResultsDuring the 1998–2012 winter seasons, the average number of all-cause, respiratory and cardiovascular deaths attributable to influenza were 1186, 794 and 21, respectively. Influenza-associated mortality was higher prior to the vaccination period than after influenza was included in the immunization program for all-cause (mean 1660 vs. 780) and respiratory (mean 1063 vs. 563) mortality, but no reduction was seen for cardiovascular mortality. The proportion of all-cause and respiratory deaths attributable to influenza was significantly lower in the post-vaccine period compared with the pre-vaccine period (P<0.001), but no reduction was seen in the proportion of cardiovascular deaths. There was an average annual reduction of 66,558years of life lost in the post-vaccine compared with the pre-vaccine period. ConclusionThe introduction of influenza vaccination within the Mexican Immunization Program was associated with a reduction in mortality rates attributable to this virus among children younger than 5years of age.

Effectiveness and Usability of a Web-Based Mindfulness Intervention for Families Living with Mental Illness

Families living with mental illness express needs of support and experiences of burden that may affect their own health detrimentally and hence also their ability to support the patient. Mindfulness-based interventions have shown beneficial health effects in both clinical and healthy populations. The aim of the current study was to explore the effectiveness and usability of a web-based mindfulness program for families living with mental illness, which was first tested in a feasibility study. The study was designed as a randomized controlled trial with an experiment group and a wait-list control group with assessments on primary and secondary outcomes at baseline, post-intervention, and at a 3-month follow-up. Significant positive improvements in mindfulness and self-compassion, and significant decreases in perceived stress and in certain dimensions of caregiver burden were found, with good program usability. Easily accessible mindfulness-based interventions may be useful in addressing caregivers’ needs of support and in preventing further ill health in caregivers. Further studies are needed, among others, to further customize interventions and to investigate the cost-effectiveness of such programs.