Association Between Short-term Exposure to Ultrafine Particles and Mortality in Eight European Urban Areas.

BACKGROUND: Epidemiologic evidence on the association between short-term exposure to ultrafine particles and mortality is weak, due to the lack of routine measurements of these particles and standardized multicenter studies. We investigated the relationship between ultrafine particles and particulate matter (PM) and daily mortality in eight European urban areas. METHODS: We collected daily data on nonaccidental and cardiorespiratory mortality, particle number concentrations (as proxy for ultrafine particle number concentration), fine and coarse PM, gases and meteorologic parameters in eight urban areas of Finland, Sweden, Denmark, Germany, Italy, Spain, and Greece, between 1999 and 2013. We applied city-specific time-series Poisson regression models and pooled them with random-effects meta-analysis. RESULTS: We estimated a weak, delayed association between particle number concentration and nonaccidental mortality, with mortality increasing by approximately 0.35% per 10,000 particles/cm increases in particle number concentration occurring 5 to 7 days before death. A similar pattern was found for cause-specific mortality. Estimates decreased after adjustment for fine particles (PM2.5) or nitrogen dioxide (NO2). The stronger association found between particle number concentration and mortality in the warmer season (1.14% increase) became null after adjustment for other pollutants. CONCLUSIONS: We found weak evidence of an association between daily ultrafine particles and mortality. Further studies are required with standardized protocols for ultrafine particle data collection in multiple European cities over extended study periods.

Mortality related to air pollution with the moscow heat wave and wildfire of 2010.

BACKGROUND: Prolonged high temperatures and air pollution from wildfires often occur together, and the two may interact in their effects on mortality. However, there are few data on such possible interactions. METHODS: We analyzed day-to-day variations in the number of deaths in Moscow, Russia, in relation to air pollution levels and temperature during the disastrous heat wave and wildfire of 2010. Corresponding data for the period 2006-2009 were used for comparison. Daily average levels of PM10 and ozone were obtained from several continuous measurement stations. The daily number of nonaccidental deaths from specific causes was extracted from official records. Analyses of interactions considered the main effect of temperature as well as the added effect of prolonged high temperatures and the interaction with PM10. RESULTS: The major heat wave lasted for 44 days, with 24-hour average temperatures ranging from 24°C to 31°C and PM10 levels exceeding 300 µg/m on several days. There were close to 11,000 excess deaths from nonaccidental causes during this period, mainly among those older than 65 years. Increased risks also occurred in younger age groups. The most pronounced effects were for deaths from cardiovascular, respiratory, genitourinary, and nervous system diseases. Continuously increasing risks following prolonged high temperatures were apparent during the first 2 weeks of the heat wave. Interactions between high temperatures and air pollution from wildfires in excess of an additive effect contributed to more than 2000 deaths. CONCLUSIONS: Interactions between high temperatures and wildfire air pollution should be considered in risk assessments regarding health consequences of climate change.

Short-term effects of ambient particulates and gaseous pollutants on the incidence of transient ischaemic attack and minor stroke: a case-crossover study.

BACKGROUND: While several studies have investigated the effects of short-term air pollution on cardiovascular disease, less is known about its effects on cerebrovascular disease, including stroke and transient ischaemic attack (TIA). The aim of the study was to assess the effects of short-term variation in air pollutants on the onset of TIA and minor stroke. METHODS: We performed secondary analyses of data collected prospectively in the North West of England in a multi-centre study (NORTHSTAR) of patients with recent TIA or minor stroke. A case-crossover study was conducted to determine the association between occurrence of TIA and the concentration of ambient PM10 or gaseous pollutants. RESULTS: A total of 709 cases were recruited from the Manchester (n = 335) and Liverpool (n = 374) areas. Data for the Manchester cohort showed an association between ambient nitric oxide (NO) and risk of occurrence of TIA and minor stroke with a lag of 3 days (odds ratio 1.06, 95% CI: 1.01 - 1.11), whereas negative association was found for the patients from Liverpool. Effects of similar magnitude, although not statistically significant, were generally observed with other pollutants. In a two pollutant model the effect of NO remained stronger and statistically significant when analysed in combination with CO or SO2, but was marginal in combination with NO2 or ozone and non-significant with PM10. There was evidence of effect modification by age, gender and season. CONCLUSIONS: Our data suggest an association between NO and occurrence of TIA and minor stroke in Greater Manchester.

Urban background particulate matter and allergic sensitization in adults of ECRHS II.

BACKGROUND: Epidemiological studies have shown weak or inconsistent associations between ambient air pollutants and allergic sensitization. The aim of this study was to evaluate whether regional urban air pollution may partly explain the large variation in the prevalence of allergic sensitization across cities of the European Community Respiratory Health Survey (ECRHS) II. METHODS: ECRHS is a cross-sectional survey initiated in 29 countries across Europe in the 1990s (ECRHS I) with a follow-up conducted 10 years later (ECRHS II). Subject characteristics were measured by questionnaires and blood tests conducted for the measurement of specific immunoglobulin E. Fine particle mass (PM(2.5), <2.5 microm) and sulphur on PM(2.5) were measured in 21 centres and annual averages of urban regional background air pollution were calculated. Results were scaled by an interquartile range increase in ambient PM(2.5) (6.03 microg/m(3)) and sulphur (1336 ng/m(3)). Generalized estimating equations were applied to compute population average effect estimates with adjustment for age, gender, smoking habit, education and number of siblings. RESULTS: A notable variation in pollution level and prevalence of allergic sensitization was observed. Moreover, exposure to urban regional background air pollution was not associated with allergic sensitization; adjusted odds ratios and 95% confidence interval were 1.02 (0.95-1.09) for PM(2.5) and 1.08 (0.86-1.31) for sulphur. These statistically non-significant associations were sensitive to model specification. CONCLUSIONS: The study suggests that regional air pollution measured at fixed sites is not associated with allergic sensitization among adults in ECRHS II.

Cat allergen level: its determinants and relationship to specific IgE to cat across European centers.

BACKGROUND: Cat allergen level in settled house dust and its determinants in Europe are unknown. OBJECTIVE: The aim of this study is to quantify the level of cat allergens in mattress dust, to study its determinants, and to analyze the relationship with cat specific IgE on community level across European centers. METHODS: Trained field workers collected dust from approximately 3000 mattresses during home visits in 22 European Community Respiratory Health Survey II centers. Sieved dust extracts were assayed for cat allergen using a mAb ELISA assay. RESULTS: The overall geometric mean cat allergen was 0.94 microg/g, ranging from 0.12 microg/g in Huelva, Spain, to 3.76 microg/g in Antwerp, Belgium. Current cat owners' homes showed substantially higher levels than past cat owners' and never cat owners' homes (geometric mean and 95% CI, 61.4 microg/g [48.4-77.9] vs 1.37 microg/g [0.97-1.9] vs 0.29 microg/g [0.27-0.31]). Community prevalence of cat ownership was moderately correlated with cat allergen levels in noncat owners (r(s) = 0.50), but not for past or current cat owners. The multilevel model identified community prevalence of cat keeping as the only statistically significant determinant of mattress cat allergen levels for noncat owners. However, averaged cat allergen levels per center were not related to community prevalence of detectable specific IgE to cat. CONCLUSION: Not having a cat in the home is associated with substantially lower Fel d 1 concentration, but does not protect against high Fel d 1 exposure in communities where cat ownership is common. CLINICAL IMPLICATIONS: People (including patients with cat allergy) who do not own cats may be exposed to high levels of cat allergen in their home, particularly if they live in communities with high levels of cat ownership.