Cristina Linares

Saharan dust and association between particulate matter and case-specific mortality: A case-crossover analysis in Madrid (Spain)

BackgroundSaharan dust intrusions are a common phenomenon in the Madrid atmosphere, leading induce exceedances of the 50 μg/m3- EU 24 h standard for PM10.MethodsWe investigated the effects of exposure to PM10 between January 2003 and December 2005 in Madrid (Spain) on daily case-specific mortality; changes of effects between Saharan and non-Saharan dust days were assessed using a time-stratified case-crossover design.ResultsSaharan dust affected 20% of days in the city of Madrid. Mean concentration of PM10 was higher during dust days (47.7 μg/m3) than non-dust days (31.4 μg/m3). The rise of mortality per 10 μg/m3 PM10 concentration were always largely for Saharan dust-days. When stratifying by season risks of PM10, at lag 1, during Saharan dust days were stronger for respiratory causes during cold season (IR% = 3.34% (95% CI: 0.36, 6.41) versus 2.87% (95% CI: 1.30, 4.47)) while for circulatory causes effects were stronger during warm season (IR% = 4.19% (95% CI: 1.34, 7.13) versus 2.65% (95% CI: 0.12, 5.23)). No effects were found for cerebrovascular causes.ConclusionsWe found evidence of strongest effects of particulate matter during Saharan dust days, providing a suggestion of effect modification, even though interaction terms were not statistically significant. Further investigation is needed to understand the mechanism by which Saharan dust increases mortality.

Short-term effect of PM2.5 on daily hospital admissions in Madrid (2003–2005)

The aim of this paper was to analyse the effect of particulate matter PM2.5, a recent air quality guideline value for the protection of health, on hospital admissions in Madrid, Spain. This dependent variable was used as a measure against the daily number of emergency hospital admissions from 2003–2005. The causes analysed were: all causes, respiratory and circulatory. The independent variables were daily records of PM2.5, PM10, NO2, NOx, SO2 and O3. Seasonalities, trend, flu epidemics, noise and pollen were used as control variables. Poisson Regression Models were performed to calculate the Relative Risk (RR) and the Attributable Risk (AR). The function relationship with hospital admissions was linear and without threshold. The RR for an increase of 25 μg/m3 in PM2.5 concentrations was 1.07 IC 95% (1.05 1.09) for all causes; for circulatory was 1.08 IC 95%: (1.03 1.13) and for respiratory was 1.07 IC 95% (1.02 1.11). PM2.5 concentrations were the only primary pollutant that showed a statistical association with hospital admissions in Madrid.

Impact of temperature and air pollution on the mortality of children in Madrid.

Learning ObjectivesAppraise the effects of individual air pollutants on mortality in children less than 10 years of age who lived in Madrid, Spain.Describe the effects of air temperature on child mortality and how pollutant levels vary seasonally.Identify biological mechanisms that may underlie the adverse effects of high pollutant levels and temperature extremes on child mortality. Abstract This work analyzes the impact of temperature and air pollution on infant mortality in Madrid. Daily values of mortality of children younger than 10 years, maximum and minimum temperatures, and air pollutants were considered for an 11-year period. In winter, mortality was mostly associated with very low temperatures and high total suspended particles (TSP) concentrations, whereas summer mortality depended crucially on the occurrence of high TSP and nitrogen oxides concentrations. In winter, the temperature effect increases dramatically for daily maximum temperature values lower than 6°C. This pattern is rather different from the one obtained for older age groups in the same location, which show the well-known V relationship between temperature and mortality. The association with TSP shows 2 linear branches without threshold and a strong increase in mortality for concentrations more than 100 &mgr;g/m3.

Desert Dust Outbreaks in Southern Europe: Contribution to Daily PM10 Concentrations and Short-Term Associations with Mortality and Hospital Admissions

Background: Evidence on the association between short-term exposure to desert dust and health outcomes is controversial. Objectives: We aimed to estimate the short-term effects of particulate matter ≤ 10 μm (PM10) on mortality and hospital admissions in 13 Southern European cities, distinguishing between PM10 originating from the desert and from other sources. Methods: We identified desert dust advection days in multiple Mediterranean areas for 2001–2010 by combining modeling tools, back-trajectories, and satellite data. For each advection day, we estimated PM10 concentrations originating from desert, and computed PM10 from other sources by difference. We fitted city-specific Poisson regression models to estimate the association between PM from different sources (desert and non-desert) and daily mortality and emergency hospitalizations. Finally, we pooled city-specific results in a random-effects meta-analysis. Results: On average, 15% of days were affected by desert dust at ground level (desert PM10 > 0 μg/m3). Most episodes occurred in spring–summer, with increasing gradient of both frequency and intensity north–south and west–east of the Mediterranean basin. We found significant associations of both PM10 concentrations with mortality. Increases of 10 μg/m3 in non-desert and desert PM10 (lag 0–1 days) were associated with increases in natural mortality of 0.55% (95% CI: 0.24, 0.87%) and 0.65% (95% CI: 0.24, 1.06%), respectively. Similar associations were estimated for cardio-respiratory mortality and hospital admissions. Conclusions: PM10 originating from the desert was positively associated with mortality and hospitalizations in Southern Europe. Policy measures should aim at reducing population exposure to anthropogenic airborne particles even in areas with large contribution from desert dust advections. Citation: Stafoggia M, Zauli-Sajani S, Pey J, Samoli E, Alessandrini E, Basagaña X, Cernigliaro A, Chiusolo M, Demaria M, Díaz J, Faustini A, Katsouyanni K, Kelessis AG, Linares C, Marchesi S, Medina S, Pandolfi P, Pérez N, Querol X, Randi G, Ranzi A, Tobias A, Forastiere F, MED-PARTICLES Study Group. 2016. Desert dust outbreaks in Southern Europe: contribution to daily PM10 concentrations and short-term associations with mortality and hospital admissions. Environ Health Perspect 124:413–419;u2002http://dx.doi.org/10.1289/ehp.1409164

Efectos de los extremos térmicos sobre la mortalidad diaria en Castilla-La Mancha: evolución temporal 1975-2003

OBJECTIVESnTo determine time trends and the geographical distribution of mortality trigger temperature thresholds due to extreme temperatures in Castile-La Mancha (central Spain) between 1975 and 2003.nnnMETHODSnThe analysis was divided into three periods (1975-1984, 1985-1994 and 1995-2003) for each province of the region. Daily mortality due to organic causes (dependent variable) was modelled using autoregressive integrated moving average (ARIMA) procedures. The resulting residual series was related to the maximum temperature series grouped in 2 degrees C intervals to obtain a threshold temperature for cold or heat when the residuals rose significantly (p<0,05) above the mean residual mortality value of the corresponding study period.nnnRESULTSnMortality trigger temperature thresholds decreased over time in Castile- La Mancha. In Toledo, the trigger temperature diminished from 40 degrees C to 38 degrees C. In Cuenca and Guadalajara, threshold temperatures for heat events were obtained in the last few decades but not in the first. These thresholds varied from the 92nd percentile in Cuenca to the 98th percentile in Albacete in the last decade. No threshold temperatures for cold spells were observed in any province or period.nnnCONCLUSIONSnCastile-La Mancha registered an upward trend in the relationship between high temperatures and mortality, probably due to population aging. This trend could have been influenced by the increased frequency of extremely hot days. Prevention plans should be periodically reviewed.

The time trend temperature-mortality as a factor of uncertainty analysis of impacts of future heat waves.

Recently, the paper by Wu et al. (2014), “Estimation and Uncertainty Analysis of Impacts of Future Heat Waves on Mortality in the Eastern United States,” concluded that “the major sources of uncertainty were the relative risk estimates for mortality on heat wave versus non–heat wave days, the RCP scenarios, and the heat wave definitions.” One conclusion to be drawn from reading this manuscript might be that a good definition of “heat wave” based on epidemiological studies and accurate determination of the risks associated with such temperatures would greatly reduce these uncertainties. Although the authors allude to the possible geographic variability of these risks, there is nevertheless no mention of the possible evolution over time that can take place both in heat-wave definition temperatures and in the modifications of these possible impacts, beyond those stemming from the use of air-conditioning equipment and the implementation of heat-wave prevention plans. n nAlong these lines, recent studies have found that demographic and socioeconomic factors may be behind the trend in minimum mortality temperatures (Miron et al. 2008). Hence, in Castile-La Mancha (Spain) the minimum mortality temperature went from 32°C in the decade 1975–1985 to 28°C in 1995–2003 as a consequence of population aging. This fact influences the heat-wave definition temperatures, which are very closely linked to the age group > 65 years (Montero et al. 2012). n nAdded to this uncertainty are the shifts over time observed in the impact of heat waves. Studies conducted in different parts of the world show that, far from remaining constant, these impacts are changing over time, with a trend toward minimizing such effects (Schifano et al. 2012): Although the effect is most pronounced in cardiovascular mortality (Ha and Kim 2013), it has remained practically constant in the case of respiratory mortality (Miron et al, in press). These results, obtained from a time series covering > 30 years, show that the increase in risk of heat-related mortality for each degree centigrade that the threshold temperature is exceeded went from 13.7% in 1975–1985 to 7.4% in 1997–2008, and specifically that this decline was attributable to circulatory causes, going from 18.2% in 1975–1985 to 5.8% in 1997–2008. In the case of respiratory causes, however, no such decline was in evidence, with the respective figures remaining practically constant: 11.8% in 1975–1985 versus 13.5% in 1997–2008. This pattern would seem to be linked to improvements in health care services (particularly in the case of patients with cardiovascular diseases), socioeconomic improvements, and the provision of infrastructures for better living conditions. It therefore follows that any changes in the trend of these parameters could reverse the situation and increase the effects of temperature extremes on mortality. This decline in heat wave–related mortality does not appear to be connected with the implementation of prevention plans, in Spain at least (Culqui et al. 2013). n nBecause the factors that appear to influence the shifts in the relationship between temperature and mortality are not local and are thus extrapolatable to a large proportion of developed countries, their relevance is self-evident. n nThese uncertainties add to those already cited in the paper by Wu et al. and highlight the need for more in-depth knowledge, not only of temperature forecasts at the different time horizons, but also of the behavior pattern over time of the temperature–mortality relationship. Far from being constant, this relationship displays a time trend that is seldom taken into account in the models used to predict the impact of climate change on human health.

Difficulties of defining the term, “heat wave”, in public health

Health Sciences Institute, Castile-La Mancha Regional Health & Social Welfare Authority, Talavera de la Reina (Toledo), Spain; Torrijos Health District, Castile-La Mancha Regional Health & Social Welfare Authority, Torrijos, Spain; Castile-La Mancha Health Service (Servicio de Salud de Castilla-La Mancha SESCAM), Talavera de la Reina (Toledo), Spain; Centro Nacional de Epidemiologia, Area de epidemiologı́a ambiental y cáncer, Madrid 28029, Spain; Instituto de Salud Carlos III. Escuela Nacional de Sanidad, Sinesio Delgado 8, Madrid 28029, Spain

Efecto de las partículas de diámetro inferior a 2,5 micras (PM 2,5 ) sobre los ingresos hospitalarios en niños menores de 10 años en Madrid

INTRODUCTIONnThe last report of World Health Organizations Air Quality Guidelines establishes a value of 10 microg/m3 as the annual mean particulate PM2.5 concentration. However, in large cities such as Madrid, this value is doubled and consequently an association between PM2.5 values and effects on morbidity and mortality is to be expected.nnnOBJECTIVEnTo analyze and quantify the influence of PM2.5 concentrations on daily hospital admissions in 0-10-year-olds in Madrid.nnnMATERIAL AND METHODSnWe analyzed the daily number of emergency hospital admissions for all causes (ICD-10: A00-R99) except traumatisms to the Gregorio Marañón General University Hospital in Madrid from 2003 to 2005. The age groups analyzed were 0-10 years and 0-1 year. A longitudinal ecological analysis of time series was performed using Poisson Regression Models. Seasonalities, trends, days of the week, and autocorrelation between morbidity series were controlled. Influenza epidemics, air pollutants, and noise and pollen concentrations were used as control variables.nnnRESULTSnThe only primary pollutant found to be statistically significant in the models was PM2.5 concentration. The relative risk associated with an increase of 10 microg/m3 in PM2.5 concentration was 1.03 (95%CI 1.00-1.05) for children less than 10 years old and 1.03 (95%CI 1.00-1.06) for infants less than 1 year old. The attributable risk was 2.7 and 2.8%, respectively.nnnCONCLUSIONSnPM2.5 concentrations are an excellent indicator of the health impact of primary pollutants in Madrid. The results obtained demonstrate the need to implement measures to reduce PM2.5 concentrations in the atmosphere in large cities.

Gaceta Sanitaria en 2016. Una nueva etapa, fortalecimiento de eGaceta e internacionalización

ria con la conformación de un nuevo equipo editorial, después de 6 años de servicio del equipo liderado por Carme Borrell y Felicitas Domínguez Berjón. El comité editorial se ha constituido tras convocatoria pública, usando las figuras que están representadas en el reglamento de SESPAS, e incluye miembros de fuera de España. El nuevo equipo firmó un acuerdo explicitando el trabajo a desarrollar en cuanto a volumen, puntualidad y calidad del servicio prestado, salvaguardando los aspectos éticos de la publicación científica y representando todas las sensibilidades profesionales que conforman SESPAS. Nuestra propuesta editorial pretende dar respuesta a los nuevos desafíos y aprovechar las oportunidades que ofrece el medio editorial actual, a la vez que continuar el excelente trabajo desarrollado por el equipo anterior1–3. Creemos que las acciones propuestas permitirán la consolidación del liderazgo de la revista en la salud pública y la gestión sanitaria en español, hacer de puerta de entrada de nuevos conceptos y profundizar en temas relevantes para la comunidad científica hispanoparlante. La propuesta fue descrita de manera detallada en un post de nuestro blog4. En ella destacan como líneas más estratégicas el desarrollo de e-Gaceta (presencia en Internet) y la internacionalización de la revista, fundamentalmente a Latinoamérica. Además, disponemos de editores/as invitados/as para desarrollar cinco estrategias: 1) evaluación de tecnologías sanitarias, 2) género, 3) comunicación, 4) e-learning y 5) salud comunitaria. Este editorial pretende dar continuidad a la ya tradicional rendición de cuentas anual dirigida a nuestros lectores/as, revisores/as y autores/as. A continuación, presentaremos brevemente las actividades realizadas durante el año pasado, así como información sobre el desempeño de la revista.

Comment on "Using Satellite-Based Spatiotemporal Resolved Air Temperature Exposure to Study the Association between Ambient Air Temperature and Birth Outcomes in Massachusetts".

In a recently published paper using space-time satellite data to determine air temperature (Ta), Kloog et al. concluded that Ta during pregnancy was associated with lower birth weight and shorter gestational age in the study population. The results obtained pointed to associations between Ta and birth weight during the last trimester, and between Ta and preterm delivery and low birth weight during the entire pregnancy. These results agree with those obtained by Dadvand et al. (2014), indicating Ta has a stressful role influencing low birth weight. n nThere are many epidemiological studies reporting a nonlinear J- or U-shaped relationship between Ta and health indicators such as mortality (Basu and Samet 2002) and morbidity (Ye et al. 2012), with different response times for heat and cold waves (Gasparrini et al. 2015). When Kloog et al. performed linear and logistic models, Ta was introduced with a linear component in multiple time windows before birth. Models also were adjusted for different environmental and sociodemographic factors. However, the authors did not control for heat and cold episodes during pregnancy. From our point of view, a similar nonlinear behavior could be expected or would at least be worth analyzing in the case of adverse birth variables. As a susceptible population group, pregnant women may be more sensitive to changes in temperature and may be at a greater risk of heat stress, because during pregnancy the increase in fat deposition and associated decrease in the ratio of body surface area to body mass result in less capacity for heat loss to the environment (Wells and Cole 2002). n nA study conducted in Rome with time-series analysis methodology (Schifano et al. 2013) showed that heat, as measured by the maximum temperature during warmer periods, was associated in the short term with preterm birth. This association with temperature was not observed in the cold periods. Similar results were obtained in Madrid (Linares et al. in press). This study considered daily maximum temperatures during heat waves (defined in Madrid during 2001–2009 as daily maximum temperatures above 34°C) and during cold waves (defined in Madrid during 2001–2009 as daily maximum temperatures below –2°C). The results for the influence of high temperatures on low birth weight were similar to those found in Rome, with the same short-term association between temperature rise and increased cases of premature birth and, consequently, low birth weight. n nThis suggests heat waves are an acute stressor on pregnant women, not the chronic stressor described by Kloog et al. The mechanism is unclear by which high temperatures may increase the risk of preterm birth, but there is evidence in the literature that supports a relationship (Carolan-Olah and Frankowska 2014). This short-term effect of Ta on adverse birth outcomes is similar to that already described for traffic noise as a factor in adverse birth outcomes in Madrid (Diaz and Linares in press). n nAlthough Kloog et al. introduced Ta values with linear components, from our point of view introducing Ta as a linear component and not taking into account the effects of heat and cold separately minimizes the authors’ ability to draw conclusions about potential impacts. The effects of high temperatures may be offset by cold temperatures. Therefore, it would be interesting to improve the analysis of Kloog et al. by taking into account the effect of Ta, but separating its effect by warm and cold seasons, especially for days within heat and cold waves.