[Long-term exposure to air pollution and natural mortality: variations related to the use of different exposure indicators in the cohorts of BIGEPI project]. / Esposizione di lungo periodo all'inquinamento atmosferico e mortalità naturale: variazioni legate all'utilizzo di diversi indicatori di esposizione nelle coorti del progetto BIGEPI.

OBJECTIVES: appropriate assessment of exposure to air pollution is crucial for the estimation of adverse effects on human health, both in the short and long term. Within the BIGEPI project, different indicators of long-term exposure to air pollution, in association with mortality by cause, were tested within the Italian longitudinal metropolitan studies (LMS). This allowed an evaluation of differences in effect estimates using the different exposure indicators. DESIGN: closed cohort. SETTING AND PARTICIPANTS: subjects aged >=30, who took part in the 2011 census, residents in 5 cities (Turin, Bologna, Rome, Brindisi and Taranto). MAIN OUTCOME MEASURES: at the time of enrolment, residential exposure levels to particulate matter <=10 µm (PM10), PM <=2.5 µm (PM2.5), nitrogen dioxide (NO2) and ozone (O3) for the period April-September (O3 warm season) were obtained from models at different spatial resolutions, from 1x1km to 200x200m (from the BEEP project) to 100x100m (ELAPSE project). In addition, locally developed models were used in each area (FARM photochemical model at 1x1-km for the cities of Rome, Taranto and Brindisi, Land-Use Regression (LUR) model for the city of Turin, PESCO model for Bologna). Cox proportional hazards models were applied to assess the association between exposure to air pollution (assessed using different exposure indicators) and natural mortality, adjusting for both individual and area covariates. RESULTS: the exposure levels derived by the different models varied between pollutants, with differences between the averages ranging from 3 to 20% for PM10, from 1 to 23% for PM2.5, and from 3 to 28% for NO2; the results for O3 were more heterogeneous. A total of 267,350 deaths from natural causes were observed. There is low heterogeneity in the effect estimates calculated from different environmental models, while there is greater variability in average exposure values, with different behaviour depending on the model and the characteristics of the area investigated. Differences are more pronounced where local risk factors are relevant, e.g., in industrial cities, thus suggesting the need of considering industrial exposure separately from other sources. CONCLUSIONS: the numerous heterogeneities in the data used make it difficult to draw conclusions about the comparisons studied. Nevertheless, this study suggests that different approaches to the assessment of environmental exposure should be evaluated depending on the national or local level of interest, also according to the specifities of the investigated areas.

[Long-term exposure to air pollution and incidence of coronary heart diseases and stroke in the longitudinal metropolitan studies (LMS) network: the BIGEPI project]. / Esposizione di lungo periodo all'inquinamento atmosferico e incidenza di malattia coronarica acuta e ictus nella rete degli studi longitudinali metropolitani: il progetto BIGEPI.

OBJECTIVES: to assess the potential of using longitudinal metropolitan studies (LMS) to study the association between long-term exposure to air pollution and the incidence of acute coronary events and stroke. DESIGN: closed cohort. SETTING AND PARTICIPANTS: subjects aged >=30 years, who took part in the 2011 census, residents in 5 cities (Turin, Bologna, Rome, Brindisi and Taranto). Annual concentrations of particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2) and warm-season ozone (O3) (annual O3 in Taranto and Brindisi), estimated through satellite (Turin, Bologna, Rome) or photochemical models (Taranto and Brindisi) with a spatial resolution of 1 km2, were assigned to the census address. MAIN OUTCOME MEASURES: incidence of coronary heart disease (CHD) and stroke until 31.12.2018 (2019 in Bologna). Cohort-specific Hazard Ratios (HRs), estimated using Cox regression models progressively adjusting for individual and contextual covariates, were pooled with random-effect meta-analysis. RESULTS: there were 71,872 incident CHD cases and 43,884 incident cases of stroke in almost 18 million person-years. No association was observed between the exposures studied and incidence of CHD and stroke, except for an increase in the incidence of CHD associated with warm-season O3 exposure (HR 1.034 per 5 µg/m3 increase). Some positive associations were found in specific cities (both outcomes in Brindisi with PM10 exposure and in Taranto with NO2 exposure, stroke in Rome with both PM10 and PM2.5), although estimates were not significant in some instances. CONCLUSIONS: LMS are a high potential tool for the study of comparative medium- and long-term effects of air pollution. Their further development (different definitions of exposure, outcomes, characteristics of the urban areas and extension to other LMS) may make them even more valuable tools for monitoring and planning public health interventions.

[The Integrated Environmental Health Impact of emissions from a steel plant in Taranto and from a power plant in Brindisi, (Apulia Region, Southern Italy)]. / L'impatto ambientale e sanitario delle emissioni dell'impianto siderurgico di Taranto e della centrale termoelettrica di Brindisi.

OBJECTIVES: to estimate the environmental and health impact attributable to PM2.5 emissions from the ex-ILVA steel plant in Taranto and the ENEL power plant in Brindisi (Apulia Region, Southern Italy). DESIGN: a SPRAY Lagrangian dispersion model was used to estimate PM2.5 concentrations and population weighted exposures following the requirements of the Integrated Environmental Authorization (IEA) of the two plants under study. Available concentration-response functions (OMS/HRAPIE and updates) were used to estimate the number of attributable premature deaths. SETTING AND PARTICIPANTS: residents in the 40 municipalities of the domains of the VDS (assessment of health damage, according to the Regional Law n. 21/2012) of Brindisi (source: Italian National Institute of Statistics 2011 Census) and residents in Taranto, Statte, and Massafra (source: cohort study). MAIN OUTCOME MEASURES: mortality from natural causes, cardiovascular and respiratory diseases, and lung cancer attributable to PM2.5. Incremental lifetime cumulative risks (ILCRs) for lung cancer associated to PM2.5 exposure. RESULTS: there was a reduction of the estimated impacts from the pre to the post IEA-scenarios in both Taranto and Brindisi. In Taranto, ILCRs greater than 1x10-4; were estimated in 2010 and 2012; the ILCR was greater than 1x10-4; in the district of Tamburi (near the plant) also for the 2015 scenario. ILCRs estimated for Brindisi were between 1x10-6; and 4x10-5;. CONCLUSIONS: the Integrated Environmental Health Impact Assessment confirmed the results of the VDS conducted according to the toxicological risk assessment approach. An unacceptable risk was estimated for Tamburi also for the 2015 scenario, characterized by a production of 4.7 million tons of steel, about half compared to one foreseen by the IEA (8 mt.).

Non-occupational exposure to heavy metals of the residents of an industrial area and biomonitoring.

In areas at high environmental risk, a major issue is the assessment of the exposure of the general population to industrial pollutants. To date, few studies have investigated exposure to heavy metals in a population residing in a high risk environmental area. The aim of this study is to evaluate the exposure to heavy metals in the industrial area of Taranto, Southern Italy, through biological monitoring techniques. We measured the levels of inorganic arsenic and methylated metabolites, lead, cadmium, chromium, and manganese in the urine samples of 279 subjects residing in Taranto and neighboring areas. After obtaining informed consent from each participant, qualified health staff administered a standardized structured questionnaire investigating lifestyle habits and assessing any confounding factors. The biological monitoring data showed high urinary concentrations of nearly all of the heavy metals investigated. These findings could be related to the presence of industrial plants and is sufficient to warrant the expectation that local and national institutions should be required to adopt preventive measures to reduce the environmental exposure of the general population to heavy metals.

[Environmental indicators in EpiAir2 project: air quality data for epidemiological surveillance]. / Indicatori ambientali nello studio EpiAir2: i dati di qualità dell'aria per la sorveglianza epidemiologica.

OBJECTIVE: construction of environmental indicators of air pollution suitable for epidemiological surveillance in 25 Italian cities for EpiAir2 project (2006-2010) and presentation of the results from a 10 years of surveillance system (2001-2010) in 10 Italian cities. DESIGN: data on particulate matter (PM10 and its fine fraction PM2.5), nitrogen dioxide (NO2), and ozone (O3), measured in the 2006-2010 calendar period, were collected. Meteorological data needed to estimate unbiased measures of the effect of pollutants are: temperature, relative humidity (estimated "apparent temperature"), and barometric pressure. In continuity with the previous EpiAir project, the same criteria for the selection of monitoring stations were applied and standard methods to estimate daily environmental indicators were used. Furthermore, it was checked the adequacy of the selected data to represent the population exposure. SETTING AND PARTICIPANTS: EpiAir2 project, relative to the period 2006-2010, involves the cities of Milano, Mestre-Venezia, Torino, Bologna, Firenze, Pisa, Roma, Taranto, Cagliari, and Palermo, already included in the previous study. The city of Treviso, Trieste, Padova, Rovigo, Piacenza, Parma, Ferrara, Reggio Emilia, Modena, Genova, Rimini, Ancona, Bari, Brindisi, and Napoli are added to the previous group. RESULTS: particulate matter concentrations have decreased in most cities during the study period, while concentrations of NO2 and ozone do not show a similar clear trend. The analysis of the trend showed annual mean values of PM10 higher than 40 µg/m(3) in some areas of the Po Valley, and annual mean values of NO2 higher than 40 µg/m(3) in the cities of Trieste, Milano, Padova, Torino, Modena, Bologna, Roma, and Napoli. CONCLUSION: the enlargement of the EpiAir project to 13 other cities has highlighted critical issues related to the different geographical areas under study. Results of EpiAir2 project point out the need of a monitoring system of air pollution concentrations in both urban and industrial sites, in order to obtain reliable estimates of exposure for resident populations and to evaluate the related time trend.

[Air pollution and urgent hospital admissions in 25 Italian cities: results from the EpiAir2 project]. / Inquinamento atmosferico e ricoveri ospedalieri urgenti in 25 città italiane: risultati del progetto EpiAir2.

OBJECTIVE: to evaluate the relationship between air pollution and hospital admissions in 25 Italian cities that took part in the EpiAir (Epidemiological surveillance of air pollution effects among Italian cities) project. DESIGN: study of time series with case-crossover methodology, with adjustment for meteorological and time-dependent variables. The association air pollution hospitalisation was analyzed in each of the 25 cities involved in the study; the overall estimates of effect were obtained subsequently by means of a meta-analysis. The pollutants considered were PM10, PM2.5 (in 13 cities only), NO2 and ozone (O3); this last pollutant restricted to the summer season (April-September). SETTING AND PARTICIPANTS: the study has analyzed 2,246,448 urgent hospital admissions for non-accidental diseases in 25 Italian cities during the period 2006- 2010; 10 out of 25 cities took part also in the first phase of the project (2001-2005). MAIN OUTCOME MEASURES: urgent hospital admissions for cardiac, cerebrovascular and respiratory diseases, for all age groups, were considered. The respiratory hospital admissions were analysed also for the 0-14-year subgroup. Percentage increases risk of hospitalization associated with increments of 10 µg/m(3) and interquartile range (IQR) of the concentration of each pollutant were calculated. RESULTS: reported results were related to an increment of 10 µg/m(3) of air pollutant. The percent increase for PM10 for cardiac causes was 0.34% at lag 0 (95%CI 0.04-0.63), for respiratory causes 0.75% at lag 0-5 (95%CI 0.25-1.25). For PM2.5, the percent increase for respiratory causes was 1.23% at lag 0- 5 (95%CI 0.58-1.88). For NO2, the percent increase for cardiac causes was 0.57% at lag 0 (95%CI 0.13-1.02); 1.29% at lag 0-5 (95%CI 0.52-2.06) for respiratory causes. Ozone (O3) did not turned out to be positively associated neither with cardiac nor with respiratory causes as noted in the previous period (2001-2005). CONCLUSION: the results of the study confirm an association between PM10, PM2.5, and NO2 on hospital admissions among 25 Italian cities. No positive associations for ozone was noted in this period.

[Air pollution and mortality in twenty-five Italian cities: results of the EpiAir2 Project]. / Inquinamento atmosferico e mortalità in venticinque città italiane: risultati del progetto EpiAir2.

OBJECTIVES: this study aims at presenting the results from the Italian EpiaAir2 Project on the short-term effects of air pollution on adult population (35+ years old) in 25 Italian cities. DESIGN: the short-term effects of air pollution on resident people died in their city were analysed adopting the time series approach. The association between increases in 10µg/m(3) in PM10, PM2.5, NO2 and O3 air concentration and natural, cardiac, cerebrovascular and respiratory mortality was studied. City-specific Poisson models were fitted to estimate the association of daily concentrations of pollutants with daily counts of deaths. The analysis took into account temporal and meteorological factors to control for potential confounding effect. Pooled estimates have been derived from random effects meta-analysis, evaluating the presence of heterogeneity in the city specific results. SETTING AND PARTICIPANTS: it was analysed 422,723 deaths in the 25 cities of the project among people aged 35 years or more, resident in each city during the period 2006-2010. MAIN OUTCOME MEASURES: daily counts of natural, cardiac, cerebrovascular, and respiratory mortality, obtained from the registries of each city. Demographic information were obtained by record linkage procedure with the civil registry of each city. RESULTS: mean number of deaths for natural causes ranged from 513 in Rovigo to 20,959 in Rome. About 25% of deaths are due to cardiac diseases, 10% to cerebrovascular diseases, and 7% to respiratory diseases. It was found an immediate effect of PM10 on natural mortality (0.51%; 95%CI 0.16-0.86; lag 0-1). More relevant and prolonged effects (lag 0-5) have been found for PM2.5 (0.78%; 95%CI 0.12-1.46) and NO2 (1.10%; 95%CI 0.63-1.58). Increases in cardiac mortality are associated with PM10 (0.93%; 95%CI 0.16-1.70) and PM2.5 (1.25%; 95%CI 0.17-2.34), while for respiratory mortality exposure to NO2 has an important role (1.67%; 95%CI 0.23-3.13; lag 2-5), as well as PM10 (1.41%; 95%CI - 0.23;+3.08). Results are strongly homogeneous among cities, except for respiratory mortality. No effect has been found for cerebrovascular mortality and weak evidence of association has been observed between ozone and mortality. CONCLUSIONS: a clear increase in mortality associated to air pollutants was observed. More important are the effects of NO2 (on natural mortality), mostly associated with traffic emissions, and of PM2.5 (on cardiac and respiratory mortality). Nitrogen dioxide shows an independent effect from the particulate matter, as observed in the bi-pollutant models.

Particulate air pollution and hospital admissions for cardiac diseases in potentially sensitive subgroups.

BACKGROUND: Although numerous studies have provided evidence of an association between ambient air pollution and acute cardiac morbidity, little is known regarding susceptibility factors. METHODS: We conducted a time-stratified case-crossover study in 9 Italian cities between 2001 and 2005 to estimate the short-term association between airborne particles with aerodynamic diameter <10 µm (PM10) and cardiac hospital admissions, and to identify susceptible groups. We estimated associations between daily PM10 and all cardiac diseases, acute coronary syndrome, arrhythmias and conduction disorders, and heart failure for 167,895 hospitalized subjects ≥ 65 years of age. Effect modification was assessed for age, sex, and a priori-defined hospital diagnoses (mainly cardiovascular and respiratory conditions) from the previous 2 years as susceptibility factors. RESULTS: The increased risk of cardiac admissions was 1.0% (95% confidence interval [CI] = 0.7% to 1.4%) per 10 µg/m PM10 at lag 0. The effect was slightly higher for heart failure (lag 0, 1.4% [0.7% to 2.0%]) and acute coronary syndrome (lag 0-1, 1.1% [0.4% to 1.9%]) than for arrhythmias (lag 0, 1.0% [0.2% to 1.8%]). Women were at higher risk of heart failure (2.0% [1.2% to 2.8%]; test for interaction, P = 0.022), whereas men were at higher risk of arrhythmias (1.9% [0.8% to 3.0%]; test for interaction, P = 0.020). Subjects aged 75-84 years were at higher risk of admissions for coronary events (2.6% [1.5% to 3.8%]; test for interaction, P = 0.001). None of the identified chronic conditions was a clear marker of susceptibility. CONCLUSIONS: An important effect of PM10 on hospitalizations for cardiac diseases was found in Italian cities. Sex and older age were susceptibility factors.

[Health impact assessment of pollution from incinerator in Modugno (Bari)]. / Valutazione ex-ante dell'impatto sulla salute attribuibile all'inquinamento da inceneritore a Modugno (Bari).

OBJECTIVES: the purpose of this study is to assess the potential health impact of the start-up of a new incinerator in general population living near the facility in Modugno, province of Bari (Puglia Region, Italy), in combination with the existent Combined-Cycle combustion Gas Turbine (CCGT) power generation facility. DESIGN: an algorithm was used to calculate the number of cases (deaths and hospital admissions) associated with a given concentrations of PM10, the exposed population, the specific mortality/morbidity rate. For every health end-point, an estimate of RR was obtained from the literature. Using PM10 as tracer, simulations were made of incinerator emissions fallout. Residents within 2 km radius from the plants were considered. RESULTS: with the reduction of the average concentration of PM10 to 40 µg/m(3), 0.12% of natural causes of death could be prevented. Proportionally, the increment in PM10 concentration of 1 µg/m(3) could be associated to 0.02% of deaths. CONCLUSIONS: the estimated health impact of the incinerator emissions doesn't modify the epidemiological profile for the population living nearby.

Susceptibility factors to ozone-related mortality: a population-based case-crossover analysis.

RATIONALE: Acute effects of ozone on mortality have been extensively documented in clinical and epidemiological research. However, only a few studies have focused on subgroups of the population especially vulnerable to these effects. OBJECTIVES: To estimate the association between exposure to ozone and cause-specific mortality, and to evaluate whether individual sociodemographic characteristics or chronic conditions confer greater susceptibility to the adverse effects of ozone. METHODS: A case-crossover analysis was conducted in 10 Italian cities. Data on mortality were collected for the period 2001 to 2005 (April-September) for 127,860 deceased subjects. Information was retrieved on cause of death, sociodemographic characteristics, chronic conditions from previous hospital admissions, and location of death. Daily ozone concentrations were collected from background fixed monitors. MEASUREMENTS AND MAIN RESULTS: We estimated a 1.5% (95% confidence interval [CI], 0.9-2.1) increase in total mortality for a 10 microg/m(3) increase in ozone (8-h, lag 0-5). The effect lasted several days for total, cardiac and respiratory mortality (lag 0-5), and it was delayed for cerebrovascular deaths (lag 3-5). In the subgroup analysis, the effect was more pronounced in people older than 85 years of age (3.5%; 95% CI, 2.4-4.6) than in 35- to 64-year-old subjects (0.8%; 95% CI, -0.8 to 2.5), in women (2.2%; 95% CI, 1.4-3.1) than in men (0.8%; 95% CI, -0.1 to 1.8), and for out-of-hospital deaths (2.1%; 95% CI, 1.0-3.2), especially among patients with diabetes (5.5%; 95% CI, 1.4-9.8). CONCLUSIONS: A greater vulnerability of elderly people and women was indicated; subjects who died at home and had diabetes emerged as especially affected.

Particulate matter and out-of-hospital coronary deaths in eight Italian cities.

OBJECTIVES: We evaluated the association between PM(10) concentration and out-of-hospital coronary deaths in eight Italian cities during 1997-2004. METHODS: 16 989 subjects aged >35 years who died out-of-hospital from coronary causes were studied and hospital admissions in the previous 2 years identified. We studied the effect of the mean of current and previous day PM(10) values (lag 0-1). A city-specific case-crossover analysis was applied using a time-stratified approach considering as confounders weather, holidays, influenza epidemics, and summer decrease in population. The pooled percentage increase (95% CI) in mortality per 10 microg/m(3) increase in PM(10) was estimated. RESULTS: A statistically significant increase in out-of-hospital coronary deaths was related to a 10 microg/m(3) increase in PM(10): 1.46% (95% CI 0.50 to 2.43). Although no statistically significant effect modification by age was found, the effect was stronger among subjects aged >65 years (1.60%, 0.59 to 2.63), particularly those aged 65-74 (3.01%, 0.74 to 5.34). People in the lowest socio-economic category (3.34%, 1.28 to 5.45) had a stronger effect than those in the highest category. No clear effect modification was seen for gender, season or any specific comorbidity. An indication of negative effect modification was seen for previous admission for cardiac dysrhythmias. Subjects without hospital admissions in the previous 2 years were slightly more affected by PM(10) effects (1.91%, 0.28 to 3.47) than those with at least one previous hospital admission (1.44%, 0.09 to 2.82). CONCLUSIONS: Our results show that short term exposure to PM(10) is associated with coronary mortality especially among the elderly and socio-economically disadvantaged. No clear effect modification by previous hospitalisations was detected except for cardiac dysrhythmias, possibly due to protective treatment.

[Urban air pollution and children respiratory hospital admissions in Pisa (Italy): a time series and a case-crossover approach]. / Inquinamento urbano e ricoveri per cause respiratorie nei bambini a Pisa: confronto tra serie temporali e case-crossover.

OBJECTIVES: we evaluated the association of daily pollutants' concentrations with daily hospital admissions for respiratory causes in children residents in Pisa during 1998-2002. We compared the results obtained with two methods of statistical analyses. A total of 657 children under ten years and admitted to local hospitals for respiratory diseases (ICD 9: 460-469, 480- 519) were included in the study. DESIGN: both time-series and case-crossover analysis were applied, controlling for temperature, holidays, influenza epidemics,rain and relative humidity. Pollutants' effects are expressed as percentage increase (and 95% CI) of hospital admissions for an increase of 10 µg/m³ of pollutants (1 mg/m³ for CO). RESULTS: with both analyses, children's hospital admissions for respiratory conditions were significantly associated to increasing daily levels of PM10 and CO at different time lags, while no association was found for NO2 and O3. In the case-crossover analysis, for a daily increase of 10 µg/m³ in PM10, a significant increment of 8.5% (CI 95% 0.02; 17.6) in children respiratory admissions was observed at lag 0-3. Results were stronger for males and during the warm season. A 1 mg/m³ increment in daily CO levels was associated with an increase of respiratory admissions at lag 0 (20.2%, CI 95% 5.3; 37.2) and at all cumulative lags: the maximum value was observed at lag 0-3 (32.6%, CI 95%8.3; 62.2). Time series analyses provides similar results, although the estimates were lower than with the other method, in terms of percentage increment and length of confidence intervals. CONCLUSIONS: this study indicates adverse effects of air pollution on respiratory health of children living in urban environment. The results of both analyses were consistent.

[Acute effects of air pollution in Brindisi (Italy): a case-crossover analysis]. / Effetti acuti dell'inquinamento a Brindisi: analisi case-crossover.

OBJECTIVE: To evaluate the association between daily air pollutant concentration and daily data regarding mortality and hospital admissions among residents of Brindisi (Southern Italy) in the years 2003-2006. DESIGN: The association between the time series of daily mortality (2003-2005) and hospital admissions (2003-2006) and the time series of daily pollutant concentration were analyzed using a case-crossover method and a conditional logistic regression. Bi-directional control periods were selected using a time-stratified approach. Models include mean temperature, relative humidity, influence of epidemics, summer decrease of resident population and holidays as confounders. Specific models with the following variables: cause of death or hospital admission, gender, age and season have been fitted. As hazard periods the following lags have been considered: single lag (from 0 to five) and cumulative lag (lag 0-1 for mortality and 0-3 for hospital admissions). MAIN OUTCOME MEASURES: A total of 1,792 subjects deceased of all natural causes (including cardiovascular and respiratory causes) and 6,925 hospital admissions for acute conditions (cardiac, cerebrovascular and respiratory diseases) were considered. PM10, NO2 and CO daily pollutant concentration series were examined. RESULTS: PM10 was associated with mortality from all natural causes (10.36%; 95% CI 1.83-19.61 at lag 0-1). The risk was more pronounced for cardiovascular mortality (14.35%; 95% CI 2.11; 28.07 at lag 1). The association with hospitalization for cerebrovascular diseases was statistically significant for PM10 among females (13.4%; 95% CI 1.7; 26.4 at lag 4) and elderly over 75 years old (13.6%; 95% CI 0.4; 28.6 at lag 4). In specific population groups, increased mortality and hospital admissions have been associated with NO2. CONCLUSION: This study found strong and consistent associations between outdoor air pollution (coming from both industrial emissions and urban traffic) and short-term increases in both mortality and morbidity. Precautionary measures should be taken.

[Methods of statistical analysis to evaluate the short term effects of air pollution in the EpiAir Project]. / I metodi di analisi statistica per la valutazione degli effetti a breve termine dell'inquinamento atmosferico nel Progetto EpiAir.

The EpiAir Project, which is funded by the Italian Center for disease prevention and control, Ministry of Health, involves 10 Italian cities for the period 2001-2005, and has the following objectives: to monitor the environmental characteristics associated with relevant health effects; to systematically collect data on relevant health outcomes, such as mortality and hospitalizations, for which the impact of air pollution has been established; to report estimates of the health effects attributable to air pollution; to identify the subgroups of the population most vulnerable to the effects of air pollution. An important part of the project deals with estimating the association between several air pollutants (PM10, NO2, O3 ) and adverse health outcomes, such as mortality for a broad spectrum of causes and hospital admissions for single disease diagnoses or diseases groups. The analyses are implemented at the city level, and then pooled estimates are calculated with random-effects metaanalyses. The present paper provides details on the statistical methodology applied, focusing on: the definition of and control for the confounding factors in the city-specific analyses, estimating the association between health outcomes and air pollution at different temporal latencies (lags), identifying population subgroups most vulnerable to PM10, and analysing the heterogeneity of the city-specific results.