Haematological and lung inflammatory effects of short-term exposure to urban particulate matter – the PM-CARE study

Background Increase in daily exposure to particulate matter (PM) in urban settings contributes to increase acute cardio-respiratory morbidity and mortality, particularly in compromised subjects. Several biological mechanisms have been postulated, including direct effects on cardiovascular system, blood, lung and indirect effects mediated through pulmonary release of oxidative stress agents. Aim To understand the mechanisms through which urban air particulate matter causes harmful effects on cardiovascular and respiratory systems. Method Three panels of non-smoking adult subjects (mean-age=63; N=79), 34 with cardiovascular disease (heart group), 18 with chronic lung disease (COPD or asthma) (lung group) and 27 healthy subjects matched by age (control group) were recruited from the patients community of L. Sacco and S. Gerardo hospitals. Each subject was investigated at home for one day during and after his/her habitual activities in Summer 2005 and subsequently will repeat the same protocol in Winter 2005/2006. Summer and Winter data will be compared at the end of the survey. Investigation consisted in daily symptom/activity recording, measurement of heart and lung functions, analysis of biomarkers of cardio-respiratory injury in blood, sputum samples and monitoring of environmental parameters. Biological samples were collected at the end of 24-h investigation. Blood cells count, Hb-concentration, fibrinogen, PT, aPTT, PF100 and cytological analysis of sputum were measured within a day of sampling; while F1+2, vWF, t-PAI, D-dimer, inflammatory/anti-inflammatory parameters (TNF-α, sR-I and II of TNF-α, IL-8, IL-10), hs-CRP, s-Nt-proBNP in blood and IL-8, TNF-α in sputum will be measured in a large batch at the end of the survey. Results Preliminary results of the Summer session showed no significant alterations in blood cell count; mean white blood cells was 5.86 103/μl (SD 1.11) for control, 6.63 103/μl (SD 1.15) for heart group and 7.11 103/μl (SD 1.79) for lung group. Mean plasma fibrinogen concentration (normal value < 400 mg/dl) was 415 mg/dl (SD 89) for control, 437 mg/dl (SD 100) for heart and 500 mg/dl (SD 122) for lung group. The collection and analysis of results will be completed in the next months. The clinical results will be complemented with data on heart and cardiovascular function and compared with those of the Winter session for each subject. Moreover, correlation will be examined between clinical parameters and individual PM monitoring results.