Sandra Mallone

Saharan dust and associations between particulate matter and daily mortality in Rome, Italy.

Background: Outbreaks of Saharan-Sahel dust over Euro-Mediterranean areas frequently induce exceedances of the Europen Unions 24-hr standard of 50 μg/m3 for particulate matter (PM) with aerodynamic diameter ≤ than 10 μm (PM10). Objectives: We evaluated the effect of Saharan dust on the association between different PM fractions and daily mortality in Rome, Italy. Methods: In a study of 80,423 adult residents who died in Rome between 2001 and 2004, we performed a time-series analysis to explore the effects of PM2.5, PM2.5–10, and PM10 on natural, cardiac, cerebrovascular, and respiratory mortality. We defined Saharan dust days by combining light detection and ranging (LIDAR) observations and analyses from operational models. We tested a Saharan dust–PM interaction term to evaluate the hypothesis that the effects of PM, especially coarse PM (PM2.5–10), on mortality would be enhanced on dust days. Results: Interquartile range increases in PM2.5–10 (10.8 μg/m3) and PM10 (19.8 μg/m3) were associated with increased mortality due to natural, cardiac, cerebrovascular, and respiratory causes, with estimated effects ranging from 2.64% to 12.65% [95% confidence interval (CI), 1.18–25.42%] for the association between PM2.5–10 and respiratory mortality (0- to 5-day lag). Associations of PM2.5–10 with cardiac mortality were stronger on Saharan dust days (9.73%; 95% CI, 4.25–15.49%) than on dust-free days (0.86%; 95% CI, –2.47% to 4.31%; p = 0.005). Saharan dust days also modified associations between PM10 and cardiac mortality (9.55% increase; 95% CI, 3.81–15.61%; vs. dust-free days: 2.09%; 95% CI, –0.76% to 5.02%; p = 0.02). Conclusions: We found evidence of effects of PM2.5–10 and PM10 on natural and cause-specific mortality, with stronger estimated effects on cardiac mortality during Saharan dust outbreaks. Toxicological and biological effects of particles from desert sources need to be further investigated and taken into account in air quality standards.

The Protective Effect of the Mediterranean Diet on Lung Cancer

There has been growing interest over recent years in the potential preventive role of the Mediterranean diet in the development of cardiovascular disease and cancer. The present study was designed to evaluate the relationship between the components of the Mediterranean diet and lung cancer. A hospital-based, case-control study of lung cancer was conducted on subjects aged 35 + yr living in the Lazio region and admitted to one of the main hospitals in Rome in the period from 1993 to 1996. Cases (n = 342) were patients with newly diagnosed primary lung cancer. Controls (n = 292) were recruited from departments of general surgery, orthopedics, ENT, and general medicine and were frequency matched by sex and age(±5yr) to the cases. Exposure characteristics were obtained by interviewing study subjects. A self-administered food-frequency questionnaire was used. After careful control for several smoking variables, we found a protective effect for high consumption of carrots (odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.42-1.05), tomatoes (OR = 0.59, 95% CI = 0.34-1.03), white meat (OR = 0.66, 95% CI = 0.42-1.02), exclusive use of olive oil (OR = 0.67, 95% CI = 0.45-0.99),and regular consumption of sage(OR=0.43,95% CI=0.29-0.65). In a multivariate model, considering all food items simultaneously, the protective effect of exclusive olive oil use and sage remained statistically significant. Our results indicate that some food items typical of the Mediterranean diet are associated with decreased lung cancer risk.

Short-Term Effects of Nitrogen Dioxide on Mortality and Susceptibility Factors in 10 Italian Cities: The EpiAir Study

Background: Several studies have shown an association between nitrogen dioxide (NO2) and mortality. In Italy, the EpiAir multicentric study, “Air Pollution and Health: Epidemiological Surveillance and Primary Prevention,” investigated short-term health effects of air pollution, including NO2. Objectives: To study the individual susceptibility, we evaluated the association between NO2 and cause-specific mortality, investigating individual sociodemographic features and chronic/acute medical conditions as potential effect modifiers. Methods: We considered 276,205 natural deaths of persons > 35 years of age, resident in 10 Italian cities, and deceased between 2001 and 2005. We chose a time-stratified case-crossover analysis to evaluate the short-term effects of NO2 on natural, cardiac, cerebrovascular, and respiratory mortality. For each subject, we collected information on sociodemographic features and hospital admissions in the previous 2 years. Fixed monitors provided daily concentrations of NO2, particulate matter ≤ 10 μm in aerodynamic diameter (PM10) and ozone (O3). Results: We found statistically significant associations with a 10-μg/m3 increase of NO2 for natural mortality [2.09% for lag 0–5; 95% confidence interval (CI), 0.96–3.24], for cardiac mortality (2.63% for lag 0–5; 95% CI, 1.53–3.75), and for respiratory mortality (3.48% for lag 1–5; 95% CI, 0.75–6.29). These associations were independent from those of PM10 and O3. Stronger associations were estimated for subjects with at least one hospital admission in the 2 previous years and for subjects with three or more specific chronic conditions. Some cardiovascular conditions (i.e., ischemic heart disease, pulmonary circulation impairment, heart conduction disorders, heart failure) and diabetes appeared to confer a strong susceptibility to air pollution. Conclusions: Our results suggest significant and likely independent effects of NO2 on natural, cardiac, and respiratory mortality, particularly among subjects with specific cardiovascular preexisting chronic conditions and diabetes.

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 daily mortality - A case-crossover analysis of individual effect modifiers

Background: Several time-series studies have established the relationship between particulate matter (PM10) and mortality. We adopted a case-crossover design to evaluate whether individual socio-demographic characteristics and chronic or acute medical conditions modify the PM10-mortality association. Methods: We selected all natural deaths (321,024 subjects) occurring among adult (aged 35+ years) residents of 9 Italian cities between 1997 and 2004. We had access to individual information on socio-demographic variables, location of death, and chronic conditions (hospital admissions in the preceding 2-year period). For in-hospital deaths, we collected information on treatment wards at time of death and acute medical conditions. In a case-crossover analysis we adjusted for time, population changes, and meteorological conditions. Results: PM10 was associated with mortality among subjects age 65 years and older (0.75% increase per 10 &mgr;g/m3 [95% confidence interval = 0.42% to 1.09%]), with a more pronounced effect among people age 85 and older. A weaker effect was found among the most affluent people. The effect was present for both out-of-hospital and in-hospital deaths, especially among those treated in general medicine and other less specialized wards. PM10 effects were stronger among people with diabetes (1.03% [0.28% to 1.79%]) and chronic obstructive pulmonary disease (0.84% [0.17% to 1.52%]). The acute conditions with the largest effect estimates were acute impairment of pulmonary circulation (4.56% [0.75% to 8.51%]) and heart failure (1.67% [0.30% to 3.04%]). Conclusions: Several factors, including advanced age, type of hospital ward, and chronic and acute health conditions, modify the PM10-related risk of death. Altered pulmonary circulation and heart failure are important effect modifiers, suggesting that cardiac decompensation is a possible mechanism of the fatal PM10 effect.

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 &mgr;m (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 &mgr;g/m3 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.

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

Objectives We evaluated the association between PM10 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 PM10 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 μg/m3 increase in PM10 was estimated. Results A statistically significant increase in out-of-hospital coronary deaths was related to a 10 μg/m3 increase in PM10: 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 PM10 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 PM10 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.