| The potential for airborne particulate matter at high concentrations to cause excess deaths was established in the mid-twentieth century by a series of air pollution "disasters" in the US and Europe which followed striking increases in mortality. By the early1990’s, time series studies, conducted at different locations, showed that air pollution levels, even at much lower concentrations can provoke increased airway resistance, bronchial inflammatory changes and genetic damage. While pollution caused by submicron particles in coal-fired fumes is serious in China, which is hazard to the atmospheric environment and people in the high risk groups, it is of great importance to find if daily exposure of airborne particulate matter would also do harm to normal adults. This study involved repeated-measure study design among a panel of46adult volunteers before and after their relocation movement from a town in rural area (A County town in Shandong Province) to urban area in Shanghai with changing air pollution levels and contents during10days’period in Shanghai.The24-h average personal samples of PM2.5ranged from108.7to736.7μg/m3in the County town in Shandong and38.6to231.9μg/m3in Shanghai while PM10levels ranged from144.9to734.3μg/m3in the town of Shandong and58.0to444.4μg/m3in urban area of Shanghai. Both PM2.5and PM10mass samples were analyzed in the laboratory for carbon black and Polycyclic Aromatic Hydrocarbons using professional techniques. The content of Polycyclic Aromatic Hydrocarbons in Shanghai were5times higher than those in the County town, and the ratio of organic to elemental carbon(OC/EC) was9.59±3.30in Shanghai and7.72±0.37in the County town, while the ratio of organic and elemental carbon(OC/EC) can be used as an auxiliary index of different air pollution type. The higher ratio in Shanghai suggested more serious secondary particles pollution compared with the County town.A total of46normal adults took part in the study with five times of repeated measurements. A10μ.g/m3decrease of PM2.5was associated with increased forced vital capacity (FVC) ranging0.78-2.69%and forced expiratory flow in1second (FEV1) was weakly associated with a0.026%(95%CI:-0.003,0.054) increase compared with the base line. Compared with PM2.5, PM10showed weak correlation with the lung function index but still was statistically significant. Association of lung function with current day PM level was more evident than that in previous1and2 days; Data on PM and its effects on the immunoglobulin shown positive correlation, significantly in the case of lag=0; Cytokinesis-block micronucleus (CBMN) assay in peripheral blood lymphocytes were used for chromosomal damage detection. The results showed that:Average MN frequency of last test in Shanghai was lower than initial one with the time span of ten days.(FR=0.72,FR95%CI=0.56-0.93;p<0.01). The changes were associated most consistently with exposures to PM2.5and elemental carbon.While acute effects are transient and due to personal-varying. Panel studies enroll a cohort of individuals and follow them over time to "catch" these changes in repeated outcome measures. This panel study design involves collecting repeat health outcome data for all46subjects over the entire study period. The pollution exposure measurement data got from personal monitors combined with fixed-site ambient monitors.In summary, the health effects of particulate matter on normal adults of daily exposure should be concerned. The results of this study might be served as evidence for optimal scheme design and basis for scientific decision in environmental management. |
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