Exposición a temperaturas extremas y riesgo de parto pretérmino en Valencia

Antecedentes y objetivos Durante las últimas décadas se ha observado un cambio en los patrones de temperatura y de determinados fenómenos meteorológicos debido al cambio climático. En el futuro se prevé además que dichas condiciones climáticas se agraven, consistentes por ejemplo con un aumento en la frecuencia, duración e intensidad de los eventos extremos de temperatura debido al calentamiento global. Existe una creciente preocupación en la comunidad científica acerca de los efectos que dichos episodios meteorológicos pueden provocar sobre la salud humana. Paralelamente, la prematuridad al nacer supone una de las principales causas de muerte infantil en todo el mundo y está asociada a la aparición de comorbilidades durante los primeros años de vida y de secuelas durante la etapa adulta. Dada la importancia que supone el periodo perinatal para el desarrollo normal del neonato a lo largo de su vida, los posibles factores de riesgo que afectan la salud de la mujer embarazada han sido objeto de estudio, especialmente durante las últimas décadas. Sin embargo, las evidencias científicas respecto al efecto de la exposición a temperaturas elevadas sobre la mujer embarazada son limitadas. El objetivo del presente trabajo es examinar la relación entre la exposición a temperaturas elevadas y el aumento de nacimientos prematuros en la zona metropolitana de Valencia durante la estación cálida del periodo 2006-2010. Metodología Se recogió información los nacimientos ocurridos durante la estación cálida (Mayo-Septiembre) del periodo 2006-2010 en la zona metropolitana de la ciudad de Valencia (N=18.026). Se obtuvo los datos de variables meteorológicas registradas en la estación del Aeropuerto de Manises, así como los diarios niveles de dióxido de nitrógeno, ozono y partículas en suspensión registrados en diferentes monitores situados en la zona de estudio. Se llevó a cabo un análisis de series temporales mediante modelos aditivos generalizados con regresión de tipo quasi-Poisson. Como confusores se introdujeron los términos de estacionalidad y largo periodo, día de la semana, vacaciones y otras variables meteorológicas (presión atmosférica y humedad relativa). La selección del modelo se realizó en base al criterio de validación cruzada generalizada. Se incluyeron funciones flexibles en forma de splines naturales en ambas dimensiones de la relación y estructura de los retardos. Se estimó el efecto de la temperatura en el riesgo de prematuridad a través de tres indicadores diferentes (temperatura aparente máxima, temperatura mínima y temperatura media diaria) en una ventana temporal de hasta tres semanas antes del parto mediante modelos no-lineales de retardos distribuidos. Para los valores de temperatura se estableció como referencia el valor de la mediana de la serie anual completa, y se estimó los riesgos relativos específicos para cada día de retardo en los percentiles 50, 90 y 99 de las series en la estación cálida. Se evaluó la asociación entre temperatura y riesgo de prematuridad en cada rango de temperatura entre los percentiles seleccionados. Se analizó el efecto de los episodios de ola de calor según la definición de EuroHeat, pero utilizando los percentiles de la distribución anual y mensual de temperaturas. Se aplicó un denominador con la población a riesgo corregido por la distribución de la edad gestacional de ésta en cada día. Se observó si el efecto principal de temperatura se modificaba al introducir los niveles de contaminación atmosférica en el modelo. Resultados Se ha obtenido un efecto inmediato con un aumento del riesgo de prematuridad de hasta casi el 30% durante los 2-3 días siguientes a la exposición a una temperatura aparente máxima superior al percentil 90. Estimaciones similares se han obtenido para la temperatura media. Para la temperatura mínima, se ha observado un incremento menor del riesgo pero un poco más duradero en el tiempo consistente en un incremento del 10% entre los 3 a 6 días después de alcanzarse valores extremos. Se observan diferencias en el patrón de distribución del efecto global de la temperatura en cada uno de los intervalos e indicadores de temperatura evaluados, con un efecto inmediato para el intervalo de temperatura aparente máxima más suave, mientras que para el rango más alto se obtiene un incremento del riesgo de prematuridad más retardado y de menor magnitud. El efecto inmediato observado en el análisis principal para temperatura mínima se obtiene sólo para el intervalo más suave. Mientras que se obtienen tres patrones claramente diferentes en el caso de la temperatura media, con un un efecto inmediato para el más suave, y efectos de similar magnitud pero más retardados para exposiciones más extremas, mientras que no se observan cambios en el riesgo de prematuridad para valores de temperatura en el intervalo intermedio. No se observan efectos consistentes de los episodios de ola de calor. Sin embargo, los resultados sugieren un posible efecto de la exposición a días de calor extremo persistente. La introducción de contaminantes en el modelo no modificó el efecto principal de la temperatura. Conclusiones La exposición a temperaturas elevadas se asoció a un aumento del riesgo de parto prematuro durante las tres semanas siguientes. Se encontró variabilidad en la magnitud y el retardo de las estimaciones del riesgo de prematuridad en función del nivel de temperatura alcanzado y del indicador de temperatura utilizado. Es necesaria la realización de futuros trabajos para avanzar en el conocimiento respecto al efecto de las temperaturas extremas sobre la salud de la mujer embarazada y el desarrollo fetal. Debido a las condiciones climáticas, ambientales y sociodemográficas específicas en cada lugar, y a la adaptación de las personas a las condiciones ambientales habituales en las que viven, los estudios deben realizarse sobre poblaciones concretas. De esta manera, se podrá obtener evidencias concluyentes para la realización de propuestas en materia de salud pública a los diferentes decisores, y con el objetivo final de diseñar planes de prevención específicos para el grupo de población de mujeres embarazadas que podrían ser potencialmente más vulnerables.Background and objectives In recent decades there has been a change in temperature and certain weather events patterns due to climate change. Future climate is predicted to have more intense, longer lasting and frequent extreme heat episodes due to global warming. There is growing concern in the scientific community about the effects that these weather events can cause on human health. Similarly, prematurity at birth is a major cause of infant death worldwide and is associated with the onset of comorbidities during the first years of life and sequelae in adulthood. Given the importance of the perinatal period for the normal development of the baby throughout his life, in recent decades the potential risk factors that can affect pregnant women’s health have been studied. However, scientific evidence regarding the effect of exposure to elevated temperatures on pregnant women is limited. The aim of this work is to examine the relationship between exposure to elevated temperatures and the increase of premature births in the metropolitan area of Valencia during the warm season of 2006-2010. Methodology Data of births occurred during the warm season (May-September) of 2006-2010 in the metropolitan area of the city of Valencia (N = 18,026) was collected. We gathered meteorological data registered at Manises Airport station, along with daily levels of nitrogen dioxide, ozone and particulate matter of different monitors located in the study area. We conducted a time series analysis using generalized additive models with quasi-Poisson regression. As confounding variables, we introduced the terms of seasonality and long-term trend, day of week, holidays and other meteorological variables (atmospheric pressure and relative humidity). Model selection was performed based on the generalized cross-validation criterion. Flexible functions were included with natural splines in both dimensions of the relationship and lag structure. Using nonlinear distributed lag models we estimated the effect of temperature on the risk of prematurity through three different indicators (daily apparent maximum temperature, minimum temperature and mean temperature) and for heat wave episode in a time window of up to three weeks. The median value of the complete annual series was established as reference, and lag-specific and accumulative relative risks in the percentiles 50, 90 and 99 of the warm season series were estimated. The association between temperature and risk of preterm birth was also evaluated in each temperature range between the selected percentiles. Heat wave effect was assessed based on the definition of EuroHeat using the percentile cutoffs of both the monthly and annual temperature distributions. We applied as denominator the pregnancies at-risk corrected for its gestational age distribution in each day. We evaluated whether the main effect of temperature was modified by introducing the levels of air pollutants in the model. Results We observed an immediate effect with an increased risk of preterm birth up to 30% 2-3 days after exposure to maximum apparent temperatures above the 90th percentile. Similar estimates were obtained for the average temperature. For minimum temperature, a milder and long-lasting effect was obtained with an increase up to 10% in the risk 3-6 days after exposure to extreme values. The results show differences in the distribution pattern of the overall effect of temperature on each of the intervals and temperature indicators evaluated, with an immediate effect for milder interval of maximum apparent temperatures, whereas a more delayed effect with lower magnitude for the extreme interval. The immediate effect observed in the main analysis of minimum temperature was only obtained in the milder interval. And three different patterns were obtained in the case of average temperature, with an immediate effect in the milder interval, and a more delayed but similar magnitude for more extreme exposures 3 weeks before childbirth, whereas no changes in preterm risk was observed for values in the intermediate interval. No consistent effects for the exposure to heat wave episode were obtained, but our results suggested a possible effect of the days with most extreme persistent temperatures during the warm season. The introduction of pollutants into the model did not alter the main effect of temperature. Conclusions The exposure to extreme temperatures was associated with an increased risk of preterm birth in the next three weeks. The risk of preterm birth varied in magnitude and delay according to the range of temperatures and the indicator. Further research is needed to advance knowledge about the effect of extreme temperatures on the health of pregnant woman. Due to the specific meteorological, environmental and socio-demographic conditions, and the adaptation that local people experience to the usual climatic conditions, studies should be performed in specific locations. Hence, conclusive evidences should be obtained with the aim of making proposals to stakeholders in the field of public health, with the ultimate goal of designing specific prevention and mitigation plans for the potentially vulnerable population group of pregnant women

Hands-on Tutorial on a Modeling Framework for Projections of Climate Change Impacts on Health.

Reliable estimates of future health impacts due to climate change are needed to inform and contribute to the design of efficient adaptation and mitigation strategies. However, projecting health burdens associated to specific environmental stressors is a challenging task because of the complex risk patterns and inherent uncertainty of future climate scenarios. These assessments involve multidisciplinary knowledge, requiring expertise in epidemiology, statistics, and climate science, among other subjects. Here, we present a methodologic framework to estimate future health impacts under climate change scenarios based on a defined set of assumptions and advanced statistical techniques developed in time-series analysis in environmental epidemiology. The proposed methodology is illustrated through a step-by-step hands-on tutorial structured in well-defined sections that cover the main methodological steps and essential elements. Each section provides a thorough description of each step, along with a discussion on available analytical options and the rationale on the choices made in the proposed framework. The illustration is complemented with a practical example of study using real-world data and a series of R scripts included as Supplementary Digital Content; http://links.lww.com/EDE/B504, which facilitates its replication and extension on other environmental stressors, outcomes, study settings, and projection scenarios. Users should critically assess the potential modeling alternatives and modify the framework and R code to adapt them to their research on health impact projections

Exploring the association between precipitation and hospital admission for mental disorders in Switzerland between 2009 and 2019.

While several studies proved the relationship between increasing temperatures and poor mental health, limited evidence exists on the effect of other weather factors, such as precipitation. This study assessed the impact of precipitation on hospital admissions for mental disorders in Switzerland between 2009-2019. We defined different precipitation events based on the duration (daily precipitation ≥1mm for 2, 3, or 4 days; PP.2/PP.3/PP.4) and intensity (≥90th percentile for 2 consecutive days; PEP90.2). First, we conducted aggregated time-stratified case-crossover analysis in eight main Swiss cities with distributed lag models to assess the association up to 3 days after the exposure. Then, we pooled the estimates in each city using a multivariate random effects meta-analysis for all hospital admissions and by subgroups (sex, age, diagnosis). Evidence of an association between precipitation and hospital admission for mental disorders was not found in Switzerland (PP.2: 1.003[0.978-1.029]; PP.3: 1.005[0.985-1.026]; PP.4: 0.994[0.960-1.030]; PEP90.2: 1.000[0.953-1.050]). Although the results were highly uncertain, we found an indication of increasing risks of hospital admission with increasing intensity of precipitation in warmer seasons (PP.2: 1.001[0.971-1.032] vs PEP90.2: 1.014[0.955-1.078]), while the risks of hospital admission slightly increased by the duration in colder season (PP.2: 1.009[0.981-1.039]; PP.3: 1.008[0.980-1.036]; PP.4: 1.017[0.956-1.081]). Overall, risks tend to be higher in people aged < 65 years. Duration of the events may influence more than intensity in females, while opposite patterns were observed in males. Risks tended to be larger but still uncertain for schizophrenia, mood disorders, and adult personality disorders. An indication of a negative association was found in neurotic disorders and null risks in the remaining groups. Although our findings did not show a clear association between precipitation and mental disorders, further research is required to clarify the role of precipitation and the potential implications of climate change and extreme precipitation events on mental health

Climate change and respiratory disease: clinical guidance for healthcare professionals.

UNLABELLED Climate change is one of the major public health emergencies with already unprecedented impacts on our planet, environment and health. Climate change has already resulted in substantial increases in temperatures globally and more frequent and extreme weather in terms of heatwaves, droughts, dust storms, wildfires, rainstorms and flooding, with prolonged and altered allergen and microbial exposure as well as the introduction of new allergens to certain areas. All these exposures may have a major burden on patients with respiratory conditions, which will pose increasing challenges for respiratory clinicians and other healthcare providers. In addition, complex interactions between these different factors, along with other major environmental risk factors (e.g. air pollution), will exacerbate adverse health effects on the lung. For example, an increase in heat and sunlight in urban areas will lead to increases in ozone exposure among urban populations; effects of very high exposure to smoke and pollution from wildfires will be exacerbated by the accompanying heat and drought; and extreme precipitation events and flooding will increase exposure to humidity and mould indoors. This review aims to bring respiratory healthcare providers up to date with the newest research on the impacts of climate change on respiratory health. Respiratory clinicians and other healthcare providers need to be continually educated about the challenges of this emerging and growing public health problem and be equipped to be the key players in solutions to mitigate the impacts of climate change on patients with respiratory conditions. EDUCATIONAL AIMS To define climate change and describe major related environmental factors that pose a threat to patients with respiratory conditions.To provide an overview of the epidemiological evidence on climate change and respiratory diseases.To explain how climate change interacts with air pollution and other related environmental hazards to pose additional challenges for patients.To outline recommendations to protect the health of patients with respiratory conditions from climate-related environmental hazards in clinical practice.To outline recommendations to clinicians and patients with respiratory conditions on how to contribute to mitigating climate change

Trends in tropical nights and their effects on mortality in Switzerland across 50 years

Increasing temperatures and more frequent and severe heat waves in Switzerland are leading to a larger heat-related health burden. Additionally, high nighttime temperatures or tropical nights (TNs) also affect the well-being of the population. We aimed to assess the spatiotemporal patterns in the frequency and the exposed population to TNs, and its mortality effect in Switzerland. We identified the TNs (minimum nighttime temperature >20˚C) in each district in Switzerland using population-weighted hourly temperature series (ERA5- Land reanalysis data set) between 1970–2019. We assessed the change in the frequency of TNs and the exposed population per district and decade through a spatiotemporal analysis. We then performed a case time series analysis to estimate the TN-mortality association (controlled for the daily mean temperature) by canton and for the main 8 cities using data on all-cause mortality at the district level between 1980–2018. We found an overall increase in the annual frequency of TN (from 90 to 2113 TNs per decade) and the population exposed (from 3.7 million to over 157 million population-TN per decade) in Switzerland between 1970–2019, mainly in the cities of Lausanne, Geneva, Basel, Lugano, and Zurich, and during the last two decades. The TN-mortality association was highly heterogeneous across cantons and cities. In particular, TNs were associated with an increase of 22–37% in the risk of mortality in the cantons of Vaud (Relative risk: 1.37 (95%CI:1.19–1.59)), Zurich (1.33 (0.99–1.79)), Lucerne (1.33 (0.95–1.87)) and Solothurn (1.22 (0.88–1.69)), while a negative association was observed in Ticino (0.51 (0.37–0.7)), Basel-Land (0.4 (0.24–0.65)) and Thurgau (0.65 (0.5–0.85)), and a null association in the remaining cantons. Our findings indicate that TNs are a relevant health hazard for a large part of the Swiss population leading to potentially larger impacts in the future due to climate change and increasing urbanization

Investigating changes in mortality attributable to heat and cold in Stockholm, Sweden.

Projections of temperature-related mortality rely upon exposure-response relationships using recent data. Analyzing long historical data and trends may extend knowledge of past and present impacts that may provide additional insight and improve future scenarios. We collected daily mean temperatures and daily all-cause mortality for the period 1901-2013 for Stockholm County, Sweden, and calculated the total attributable fraction of mortality due to non-optimal temperatures and quantified the contribution of cold and heat. Total mortality attributable to non-optimal temperatures varied between periods and cold consistently had a larger impact on mortality than heat. Cold-related attributable fraction (AF) remained stable over time whereas heat-related AF decreased. AF on cold days remained stable over time, which may indicate that mortality during colder months may not decline as temperatures increase in the future. More research is needed to enhance estimates of burdens related to cold and heat in the future

Allergies to food and airborne allergens in children and adolescents: role of epigenetics in a changing environment.

Allergic diseases affect millions of children and adolescents worldwide. In this Review, we focus on allergies to food and airborne allergens and provide examples of prevalence trends during a time when climate change is of increasing concern. Profound environmental changes have affected natural systems in terms of biodiversity loss, air pollution, and climate. We discuss the potential links between these changes and allergic diseases in children, and the clinical implications. Several exposures of relevance for allergic disease also correlate with epigenetic changes such as DNA methylation. We propose that epigenetics could be a promising tool by which exposures and hazards related to a changing environment can be captured. Epigenetics might also provide promising biomarkers and help to elucidate the mechanisms related to allergic disease initiation and progress