Do exposure to outdoor temperatures, NO2 and PM10 affect the work-related injuries risk? A case-crossover study in three Italian cities, 2001-2010.

OBJECTIVES: Studies on the effect of temperature on rates of work-related injuries (WRIs) are very recent, and are evolving in depth and scope. However, less is known about potential effects of air pollutants. Our objective was to analyse the association between WRI and NO2, PM10 and air temperature in three major Italian cities, and to identify groups of workers more at risk in Italy. DESIGN: Time-stratified case-crossover study. SETTINGS: Milan, Turin, Rome, years 2001-2010. PARTICIPANTS: A total of 468 816 WRI occurred between 2001 and 2010 in Milan, Turin and Rome were extracted from the Italian national workers' compensation authority database. MAIN OUTCOMES: Associations between WRI and temperature, PM10, NO2, separately in the warm and in the cold season (WS, May-September; CS, November-February). Effect modification was studied by economic sector, occupational activity and indoor/outdoor job activity. RESULTS: Exposure to NO2 (lag 0-8) showed the highest effect on the risk of WRI,with ORs ranging from 1.20 (95% CI 1.16 to 1.24) in Milan to 1.30 (95% CI 1.24 to 1.37) in Turin in the WS. The effect of exposure to PM10 was milder but consistent across all cities: ORs from 1.09 (95% CI 1.05 to 1.12) in Turin to 1.15 (95% CI 1.11 to 1.18) in Rome. Temperature was associated with risk of WRI only among those working in construction (highest association in Rome 1.06; 95% CI 1.01 to 1.12), transportation (highest association in Milan 1.05; 95% CI 0.96 to 1.14) and the energy industry (highest association in Milan 1.57; 95% CI 1.03 to 2.38) in the WS in all cities. A weak effect of low temperatures was observed in the CS only in Rome. CONCLUSIONS: Exposures to NO2 resulted as strongest hazard for WRIs, mainly in warm months, while the independent effect of temperature was significant only in specific subgroups of workers. These results could be considered to better plan safety prevention programmes.

[Effects of high temperature and air pollution on the risk of preterm births. Analysis in six Italian cities, 2001-2010]. / Effetti delle alte temperature e dell'inquinamento atmosferico sul rischio di nascita pretermine. Analisi in sei città italiane, 2001-2010.

OBJECTIVES: to evaluate the association between short term maternal exposure to high temperature and air pollution on preterm births (PBs), which represent the first cause of perinatal mortality and morbidity in developed Countries, and to identify maternal risk factors enhancing individual susceptibility. DESIGN: time series. SETTING E PARTICIPANTS: all singleton live-births occurred in six Italian cities between 1st April and 31st October of each year in the period 2001-2010 were identified through the Certificate of Delivery Care Registry (CedAP). MAIN OUTCOME MEASURES: births occurred between 22nd and 36th week of gestation were defined as preterm births. Daily values were obtained for maximum apparent temperature (MAT), PM10, NO2, and O3. Exposures-preterm births association was estimated using a generalized additive model (GAM) with a Poisson distribution. Exposure and city-specific lag structure were computed using a non-linear distributed lag model (DLNM). RESULTS: 121,797 newborns were enrolled, 6,135 (5.0%) of which were PBs. For MAT, a linear relationship was observed for Turin (Piedmont Region, Northern Italy), Trieste (Friuli Venezia Giulia Region, Northern Italy), Rome (Lazio Region, Central Italy), and Palermo (Sicily Region, Southern Italy), while non-linear relationship was found for Bologna (Emilia-Romagna Region, Northern Italy) and Venice (Veneto Region, Northern Italy). The relative risks (RR) for MAT, computed comparing the 90th vs. the 75th percentile, vary from 1.02 (95%CI 0.95-1.09; lag 0-2) in Palermo to 1.94 (95%CI 1.32-2.85; lag 0-3) in Venice. For pollutants, a significant effect for 10 µg/m3 (IQR) increase of PM10 in Rome (RR: 1.07; 95%CI 1.02-1.12; lag 12-22) and for 16 µg/m3 (IQR) increase of O3 in Palermo (RR: 1.29; 95%CI 1.03-1.62; lag 2-9) was detected. In Rome, a significant effect modification by age and education level of the MAT-PB relationship and by education level and clinical conditions of PM10-PB was found. CONCLUSIONS: results showed a clear positive association between MAT and the risk of NP and a lower and variable effect of pollutants. It is important and necessary to limit the impact of these risk factors on the probability of NP with appropriate prevention programmes.

The Modifying Role of Socioeconomic Position and Greenness on the Short-Term Effect of Heat and Air Pollution on Preterm Births in Rome, 2001-2013.

Urban green spaces have been associated with health benefits, but few studies have evaluated the role of greenness on pregnancy outcomes. We examined how the association between short-term exposure to heat and air pollution on the probability of preterm delivery is affected by the spatial variation of socioeconomic position (SEP) and greenness. We analyzed a cohort of newborns in Rome, from April to October of 2001-2013, defining preterm as births between the 22nd and the 36th week of gestation. We used a time series approach, with maximum apparent temperature (MAT), PM10, NO2, and O3 as exposure variables. As greenness indicators, we considered maternal residential proximity to green spaces and the Normalized Difference Vegetation Index (NDVI) within a 100 m buffer around each woman's residential address. We enrolled 56,576 newborns (5.1% preterm). The effect of a 1 °C increase in temperature on the daily number of preterm births was higher in women with low SEP (+2.49% (90% CI: 1.29-3.71)) and among those living within 100 m from green spaces (+3.33% (90% CI: 1.82-4.87)). No effect modification was observed for NDVI or PM10. SEP was an important effect modifier of the heat-preterm birth relationship. The role of greenness in modifying this association between heat and preterm delivery should be further investigated.

[A systematic review of epidemiological cohort studies based on the Italian Medical Birth Register. Is it time to think of a multicentric birth cohort?] / Una revisione sistematica degli studi epidemiologici basati su coorti CeDAP in Italia. Possibile pensare a una coorte di nascita multicentrica?

INTRODUCTION: birth cohorts are a necessary tool for the study of the effects of exposures which can occur during pregnancy and early life on the development and health status in paediatric and adult life. The Italian Medical Birth Register (CeDAP), linked with other health administrative data, allows to build population based births cohorts to be followed over time. OBJECTIVES: to sistematically review all published scientific papers using data extracted from the (CeDAP) in order to give a picture of their current use for epidemiological aims; to describe advantages and limits of these data and possible future developments for epidemiological purposes. METHODS: a systematic review was conducted using PubMed, identifying all peer-reviewed research papers in English or Italian published by November 2015, by combining of free text and MeSH terms, where available. Features of included papers have been double checked and possible disagreements have been discussed to reach consensus. RESULTS: the research strategy found 720 papers, 35 of which fulfilling the required criteria. Only few Italian regions used CeDAP data for epidemiological studies, particularly Lazio and Umbria (Central Italy) and Emilia-Romagna and Friuli Venezia Giulia (Northern Italy). About half of the included papers were analytical, while the others were descriptive. Occurrence of caesarean deliveries and the prevalence of malformations were the most recurrent topics. Almost all papers used only data at delivery, whereas 5 papers used a longitudinal design with follow-up after birth. CONCLUSIONS: the Italian CeDAP registry is an important source of information for epidemiological research and its use for both aetiological aims and health services assessment should be enhanced. Furthermore, its characteristics, in particular its homogeneity among all Italian regions, might allow to create a multiregional birth cohort to be regularly followed up.

[An example of the integrated use of administrative health databases for the study of childhood cancer clusters]. / Un esempio di uso integrato di banche dati sanitarie correnti per lo studio dei cluster di tumori infantili.

We developed an algorithm to select incident cases of lymphatic and haematopoietic system in children, in order to create a timely and accurate database of incident cases to answer the needs of cluster analysis. This group of cancers is by far the most frequent in the paediatric age. The procedure has been applied to identify incident cases in children aged 0-14 years, resident in Rome (Central Italy), and diagnosed between 2000 and 2011. The algorithm links hospital discharge records (SDO), the hospital registry of the Italian Association of paediatric haematology and oncology (AIEOP), and the Population Registry. We identified 391 cases of cancers of lymphatic and haematopoietic system; among them, the most frequent pathology is the lymphoid leukaemia, which represents 52% of total cases, followed by non-Hodgkin lymphoma (21% of total cases). Results correspond to data from literature and to the estimates from the Italian Association of cancer registries (AIRTUM), giving value to the used procedure.

[Cluster statistical analysis in epidemiology]. / L'analisi statistica dei cluster in epidemiologia.

Statistical analysis represents a critical point in cluster analysis, because a methodology able to take into consideration the complexity of this analysis has not yet been developed. However, a common approach in statistical analysis of a suspected cluster is a necessary tool for public health operators who have to face population worries and requests. We propose an approach for the analysis of clusters and discuss the main limitations and strengths of the used methods. To this aim, we present, as a case study, the spatial clustering analysis of acute lymphoblastic leukaemia (ALL) cases among children in Rome between 2000 and 2011. Cases were selected through a record linkage of three different health and administrative current databases. Cases were geocoded at 3 spatial resolutions: 20 districts (D), 155 neighbourhoods (NB), and 5,812 census areas (CA). Indirect standardized incidence ratios (SIR) were computed for the NBs with Rome average incidence rate (IR) of ALL as reference and then smoothed by Besag-York-Mollie (BYM) model. General clustering was tested by Tango statistics, whereas localized clustering was detected through two different statistics: Besag and Newell's, and Kulldorf and Nagarwalla's. Both general and local clustering were tested at city level, using NBs as area units, and at district level, using CAs as area units. We identified 194 ALL cases in the 0-14 age group (IR: 43.7x1,000,000). SIRs ranged between 0.00 and 18.1 among NBs. After smoothing, a significant excess of cases was identified only in 3 Ds. At city level, no general clustering was highlighted (Tango's test p-value: 0.08), while both tests for local clustering were significant in one of the 3 Ds with the highest SIRs. Finally, at district level, although no general cluster was founded, a total of 7 clusters were identified in the 3 Ds with the highest SIRs, each cluster being composed by a number of cases ranging between 2 and 6. Results indicate the presence of clusters in some areas of Rome, which are evident only when the finest spatial resolution is used. This standardised procedure is an important tool to properly analyse potential clusters.

[Literature review of childhood leukaemia cluster investigations]. / Revisione degli studi di cluster di leucemia infantile.

Since the first report of a possible cluster of childhood leukaemia in 1963, many studies have shown a tendency to clustering in space and/or in time of this disease. This paper summarizes the studies about clusters of childhood leukaemia in the international context and in Italy, and discusses the aetiological hypotheses particularly in reference to exposures in the area of residence. Thirty-three cluster studies have been identified through a literature search performed using the PubMed bibliographic database, websites of main national and international health authorities, and relevant reviews published on this topic. Most of leukaemia cluster studies were conducted following an alarm in the nearby areas of a point source of toxic substances as nuclear power plants, chemical-industrial sites, military bases, broadcasting antennas. As alternative explanation, in several clusters an infectious aetiology was hypothesized (population mixing or delayed infection hypothesis). The uncertainty associated with cluster investigations underlines the importance of applying rigorous methods and transparent decision making, involving parents of children with cancer and the local community, and taking into account all potential aetiological factors, especially those for which a biological plausibility exists.

[Investigative model for the evaluation of spatio-temporal clusters of childhood cancers]. / Modelli di indagine per la valutazione di cluster spazio-temporali di tumori infantili.

This paper describes the conceptual framework and the critical issues of investigations of clusters of childhood cancers and defines an investigative model for the health authorities responsible for assessing a suspected cluster, taking into account the guidelines available and considering the most recent advances of the Geographical Information System and of the specific statistical methodology. Three main investigation phases are identified: the first consists in the preliminary study on the health of population living in the area where the cases are defined and aetiological hypotheses are formulated; the second is the cluster evaluation study using statistical methods assessing the spatial heterogeneity and collecting information about potential risk factors; the third is the analytical epidemiological study to test aetiological hypotheses suggested by the previous phases. The residential cohort approach is the most valid to date to assess long-term effects, and allows to reconstruct the lifetime residential history from the population registry. The researchers' decision on how detailed about a suspected cluster the investigation has to be needs to take into account both the level of alarm in the population and the limited resources available. The concern about a suspected cluster of cancer cases should always be addressed, even if this implies to acknowledge limits of research and uncertainty in results interpretation.

The association between extreme weather conditions and work-related injuries and diseases. A systematic review of epidemiological studies.

INTRODUCTION: The relationship between extreme temperature and population health has been well documented. Our objective was to assess the evidence supporting an association between extreme temperature and work related injuries. METHODS: We carried out a systematic search with no date limits using PubMed, the Cochrane central register of controlled trials, EMBASE, Web of Science and the internet sites of key organizations on environmental and occupational health and safety. Risk of bias was evaluated with Cochrane procedure. RESULTS: Among 270 studies selected at the first step, we analyzed 20 studies according to inclusion criteria (4 and 16 referring to extreme cold and heat temperature, respectively). DISCUSSION: Despite the relevance for policy makers and for occupational safety authorities, the associations between extreme temperature and work related injuries is seldom analyzed. The estimation of risk, the identification of specific jobs involved and the characterization of the complex mechanisms involved could help to define prevention measures.

Temperature in summer and children's hospitalizations in two Mediterranean cities.

BACKGROUND AND OBJECTIVE: Children are potentially vulnerable to hot ambient temperature. However, the evidence on heat-related children's morbidity is still scarce. Our aim was to examine the association between temperatures in summer (May to September) and children's hospitalizations in two Mediterranean cities, Rome and Valencia, during the period 2001-2010. METHODS: Quasi-Poisson generalised additive models and distributed lag non-linear models were combined to study the relationship between daily mean temperature and hospital admissions for all natural, respiratory and gastrointestinal diseases in children under 15 years of age. Associations were summarised as the percentage of change (Ch%) in admissions at 50th, 75th, 90th, 95th and 98th percentiles of temperature in summer compared to 1.) the 50th percentile in the whole year (50th(y)) and 2.) the preceding percentile in the previous series. Cumulated risks were obtained for groups of lags showing a similar pattern: 0-1, 2-7, 8-14 and 15-21 days. RESULTS: Almost whatever increase of temperature from 50th(y) was significantly associated with an increase of paediatric hospitalizations by all natural diseases at short term (lag 0-1), while small increases at high temperatures only had a delayed effect on this outcome. The same pattern was observed in Rome for respiratory admissions, while in Valencia only a delayed association (days 8-14) was observed. The increase of temperature from 50th to 75th percentiles was associated at short time to an increase of gastrointestinal admissions in both cities. CONCLUSION: Children's hospitalizations rose with heat in Rome and Valencia. Patterns of delays and critical windows of exposure mainly varied according the outcome considered.

Heat and air pollution exposure as triggers of delivery: A survival analysis of population-based pregnancy cohorts in Rome and Barcelona.

INTRODUCTION: Environmental exposures have been linked to length of gestation but the question as to during which weeks of gestation pregnancies are most susceptible still remains little explored. We estimated the effect of maximum apparent temperature and air pollution levels on risk of birth by week of gestation. METHODS: We analyzed two cohorts of singleton live births in Rome (2001-2010) and Barcelona (2007-2012). Maximum apparent temperature (MAT), PM10, O3 and NO2 were analyzed in the warm period (1st April-31st October). Gestational week-specific hazard ratios of giving birth associated to a 1-unit increase in exposure were estimated fitting Cox regression models adjusted for seasonality, and demographic and clinical characteristics of the mother. RESULTS: We observed 78,633 births (5.5% preterm) in Rome and 27,255 (4.5% preterm) in Barcelona. The highest hazard ratios for 1°C increase in MAT were in the 22nd-26th weeks of gestation, 1.071, (95% CI 1.052-1.091) in Rome and 1.071 (95% CI 1.036-1.106) in Barcelona, and decreased to 1.032 (95% CI 1.026-1.038) and 1.033 (95% CI 1.020-1.045) at the 36th week of gestation, respectively. Similar associations and trends were observed for PM10 and NO2 after adjusting for MAT. O3 showed similar trends but weaker associations. CONCLUSIONS: We found, consistently in Rome and Barcelona, an increased risk of delivery for a unit increase in MAT, PM10, NO2 and O3, especially in the second half of the second trimester, thus effectively increasing the risk of preterm and particularly early preterm birth. Results may help to increase awareness of these risks among public-health regulators and clinicians, leading to better preventive strategies.

The effect of heat waves on mortality in susceptible groups: a cohort study of a mediterranean and a northern European City.

BACKGROUND: Climate change is projected to increase the number and intensity of extreme weather events, for example heat waves. Heat waves have adverse health effects, especially for the elderly, since chronic diseases are more frequent in that group than in the population overall. The aim of the study was to investigate mortality during heat waves in an adult population aged 50 years or over, as well as in susceptible subgroups of that population in Rome and Stockholm during the summer periods from 2000 to 2008. METHODS: We collected daily number of deaths occurring between 15th May and 15th September each year for the population above 50 as well as the susceptible subgroups. Heat wave days were defined as two or more days exceeding the city specific 95th percentile of maximum apparent temperature (MAT). The relationship between heat waves and all-cause non-accidental mortality was investigated through time series modelling, adjusting for time trends. RESULTS: The percent increase in daily mortality during heat waves as compared to normal summer days was, in the 50+ population, 22% (95% Confidence Interval (CI): 18-26%) in Rome and 8% (95% CI: 3-12%) in Stockholm. Subgroup specific increase in mortality in Rome ranged from 7% (95% CI:-17-39%) among survivors of myocardial infarction to 25% in the COPD (95% CI:9-43%) and diabetes (95% CI:14-37%) subgroups. In Stockholm the range was from 10% (95% CI: 2-19%) for congestive heart failure to 33% (95% CI: 10-61%) for the psychiatric subgroup. CONCLUSIONS: Mortality during heat waves increased in both Rome and Stockholm for the 50+ population as well as in the considered subgroups. It should be evaluated if protective measures should be directed towards susceptible groups, rather than the population as a whole.

Effect of ambient temperature and air pollutants on the risk of preterm birth, Rome 2001-2010.

INTRODUCTION: Although the prevalence of preterm births ranges from 5 to 13% and represents the leading cause of perinatal mortality and morbidity in developed countries, the etiology of preterm birth remains uncertain. We aimed to evaluate the effect of short-term exposure to high and low temperatures and air pollution on preterm delivery and to identify socio-demographic and clinical maternal risk factors enhancing individual susceptibility. METHODS: We analyzed all singleton live births by natural delivery that occurred in Rome in 2001-2010. A time-series approach was used to estimate the effect of exposure to minimum temperature, maximum apparent temperature, heat waves, particulate matter with an aerodynamic diameter of 10µm or less (PM10), ozone, and nitrogen dioxide in the month preceding delivery; the analysis was conducted separately for cold and warm seasons. Socio-demographic and clinical risk factors were included as interaction terms. RESULTS: Preterm births comprised nearly 6% of our cohort. An increase of 1.9% (95% confidence interval (CI) 0.86-2.87) in daily preterm births per 1°C increase in maximum apparent temperature in the 2days preceding delivery was estimated for the warm season. Older women, women with higher education levels, and women with obstetric or chronic pathologies reported during delivery had a lower effect of temperature on the risk of preterm birth, while women with a chronic disease in the two years before delivery and mothers<20years showed a higher effect. A +19% (95% CI 7.91-31.69) increase in preterm births was observed during heat waves. Temperature had no effect during the cold season. We detected a significant effect of PM10 on preterm-birth risk at a lag period of 12-22days during the warm season (+0.69%; 95% CI 0.23-1.15, for 1µg/m(3) increase of pollutant); women with obstetric pathologies and with a higher education level showed a higher risk. CONCLUSIONS: Our results suggest a possible short-term effect of heat and a more delayed and prolonged effect of PM10 exposure on preterm-birth risk, as well as the existence of more susceptible subgroups of women. Our observations support the few reported investigations, and may help to increase awareness among public-health stakeholders and clinicians regarding the role of these environmental exposures as risk factors for premature birth and health consequences for children later in life.