EUROEPI2010 -EPIDEMIOLOGY AND PUBLIC HELTH IN AN EVOLVING EUROPE XXXIV Congresso dell’Associazione Italiana di Epidemiologia - Florence, 6-9 Novembre 2010 PARTICULATE MATTER FROM A PARTICLE NUMBER COUNTER AND HEALTH EFFECTS IN TURIN, ITALY: PRELIMINARY RESULTS. M. Serinelli1, A. Tittarelli2, G. Berti3, M. Bertoldi2, A. Borgini2, P. Crosignani2, E. Cadum3 1Regional Environmental Protection Agency, Puglia, Bari, Italy, 2Cancer Registry and Environmental Epidemiology Unit, National Cancer Institute, Milan, Italy 3Epidemiology and Environmental Health, Regional Environmental Protection Agency, Piedmont, Italy INTRODUCTION AND OBJECTIVES Epidemiological research has found correlation between exposure to particulate matter (PM) and health effects. Supposing that the total surface of the particles closer correlate with tissue damage, we evaluated the daily PM concentration, usually expressed as a mass, through a measurement of the number of particles. To evaluate the associations between PM levels and acute health effects using innovative monitoring instruments that will allow the fine fraction analysis. RESULTS In the first step, for the mortality, except that for cardiac causes, we observed percent increases always above 0 but never statistically significant, with higher risks for respiratory causes. Among subjects aged 75-84 years, we observed significant effects of PM on cerebrovascular (PM10: 3.95%; CI 95% 0.42; 7.60; PM2.5: 6.18%; CI 95%: 0.33;12.37) and respiratory mortality (PM10: 5.59%; CI 95% 1.03 ;10.36; PM2.5: 8.6%, CI 95%; 1.13; 16.64). Subjects aged 75-84 years were at risk for hospital admission for cerebrovascular and respiratory diseases (PM10: 2.53%, CI95%: 0.74;4.36 ; PM2.5: 3.57%; CI 95% 0.93; 6.28). Figure 1 and 2 show the results of the case-crossover analysis of the effect of particle numbers on deaths of subjects aged over 35 and on morbidity (all ages). The highest and most significant values were found both for respiratory mortality (n5:10.63% CI 95%: 0.29; 22.05) and morbidity (n5: 4.55%, CI95:.0.56; 8.69 ) at lag 0-1. among those aged over 65 years old. In the case-crossover analysis by subgroup, the findings were very similar to the first step: the age groups most clearly susceptible to the effects of air pollution were the 75 - 84 groups. for respiratory mortality (n5: 32.25%, CI95%: 4.95; 66.66) and cerebrovascular (n1: 23.29%, CI 95%: 3.10; 47.43 ) and for respiratory hospital admissions (ranged from 12.63% for n2 to 9.34% for n5) . The effect appears stronger among the men and in cold season for cerebrovascular mortality and hospital admissions and for respiratory mortality. 1 MATERIAL AND METHODS 7.144 subjects resident in Turin, aged over 35 years and died for all causes (ICD 9: 1-799), cardiac (390-429), cerebrovascular (430-438) and respiratory causes (460-519) were considered, as well as acute hospital admissions (all ages) for the same diseases (excluded all causes). An optical particle counter was placed over a period of one year (from August 2005 to July 2006) in an urban background station in the city of Turin. In a first step, particle masses were calculated from the particle counter data, and expressed as m/m3. A case-crossover analysis was applied using a “time-stratified” approach, controlling for influenza, holidays, population decrease, temperature. Analyses were stratified for gender, age classes and season of death or hospitalization (cold: 1st October -31th March; warm: 1st April-30th September). In the firtst step, results are expressed as percent increase mortality/hospitalization for 10 m/m3 PM increase for single-day lags (0) (only for cardiac and cerebrovascular hospital admissions) and for a cumulative lag (0-1) for mortality and for respiratory hospital admissions. Then, in a second step, percent increase of risk was calculated for an increment in exposure corresponding to the interquartile range of particle numbers in the following range of diameters: n1: 0.3–0.5 mm n2: >0.5–0.7 mm n3: >0.7–1.0 mm n4: >1.0–2.5 mm n5: >2.5–10 mm. Table 1 displays levels of the environmental variables considered in analyses, Figure 1 - Association between particle numbers deaths (over 35 ys): percent increases of risk associated with an interquartile range variation of particle numbers for cumulative lag 0-1, Turin, 2005–2006 Figure 2- Association between air pollutants and hospital diseases (all ages): percent increases of risk associated with an interquartile range variation of particle numbers for single and cumulative lag Turin, 2005–2006 Table 1 Description of environmental variables CONCLUSION We analyzed short terms effects for a short period (about 1 year) of available data. The preliminary findings suggest that: a particle counter might be suitable for assessing particular matter variability; further investigation are necessary for particulate fine fraction