Figure 2 Scheme for ultrafine particle concentrator

1. Subchronic Effects of Concentrated Ambient Particles on Cardiovascular Toxicity in Rats with Myocardial Injury Chen, PJ1; Huang, CH3; Li, WL1; Wang, PY2; Yan, YH1,4; Cheng, TJ1 1Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University ; 2Institute of Environmental Engineering, National Central University ; 3Department of Emergency Medicine, National Taiwan University Hospital; 4Department of Internal Medicine, Chia-Yi Christian Hospital Background and objective Result • Epidemiologic studies have shown that ambient particulate matter (PM) is associated with the mortality and hospital admissions of congestive heart failure. However, the mechanism is still unclear. The objective of this study is to investigate the subchronic effects of concentrated ambient particles (CAPs) on cardiovascular toxicity in rats with myocardial injury. Method Male SD rats received 150 mg/kg isoproterenol by subcutaneous injection to induce myocardial injury. Ultrafine particle concentrator (UFPC) was used for subchronic CAPs exposure (Whole body inhalation exposure, 5 hours/day, 4 days/week for 13 weeks). We used markers of left ventricle dysfunction, inflammation and coagulation (BNP, CRP, fibrinogen)and hemodynamic test to evaluate the effect of CAPs on cardiovascular toxicity. (figure 1, 2) Table 1 Heart weight, BALF and biomarkers in CAPs and filtered air group Figure 2 Scheme forultrafine particle concentrator Figure 4 CAPs mass concentration during exposure (148.6 ± 83 µg/m3 in average during exposure; 23.2 µg/m3 in average in 13 weeks) Figure 3 Enrichment factor of concentrator during exposure (6.4 ± 1.3 folds in average) N=5 in CAPs group, N=5 in filtered air group * p<0.05 Table 3 Heart rate variability in CAPs and filtered air group Table 2 Hemodynamic test in CAPs and filtered air group Figure 1 Experimental framework N=4 in CAPs group, N=3 in filtered air group * p<0.05 †p<0.1 N=4 in CAPs group, N=4 in filtered air group N=3 in CAPs group for LV pressure and dp/dt measurement * p<0.05 Conclusion Figure 5 Particle size distribution in exposure chamber Our results showed that PM exposure in rats with myocardial injury had no obvious acute or chronic effect in left ventricle, but increased fibrinogen level and altered cardiac autonomic function. Our results suggest cardiovascular risk factors may increase after chronic exposure to ambient particle under present PM concentration.