| Objective 1. To investigate acute damage effects of fine particle (PM2.5) in sand dust storm on lung cells ,alveolar macrophages(AM)alveolus,neutrophil (PMN) in rat. 2. To study the acute and chronic effects of sand dust storm on the human health. Methods: 1. Male Wistar rats were randomly divided into control group, low-dose group, midst-dose group and high-dose group, each with six rats. The rats were perfused with particulate suspensions of 0, 1.5, 7.5,37.5 mg/kg dose by intratracheal instillation. After being instilled, rats were sacrificed at 12,24,48 hours respectively, eath sacrificed about 24 .DNA damage of lung cells of rats was detected with single cell gel electrophoresis(SCGE) technique, the morphology of living cells , apoptosis and necrosis in lung cells , dealed with apoptosis detection kit ,were observed by fluorescence microscope. The lung macrophages, neutrophils of rats were observed and counted through microscope. 2.About 1583 inhabitants and 1134 juveniles who were in grade 3,6,7,8 from district where sand dust storm happened frequently and infrequently were selected by stratified sampling and cluster sampling method and visited face-to-face to collect the information of diseases and symptoms in respiratory, circulatory system and so on. 428 of juveniles were selected to measure the activity of saliva Lysozyme in saliva by turbidimetric method. Results: 1 .Experimental result of toxicology. (1) DNA damages were observed in rat lung cells of every sect time and concentration of fine particles(PM2.5) in sand dust storm , It showed the longest trail at 12th hour, followed by 48th hour, the shortest trail at 24th hour. There exist dose-effect relation in each group. (2).After instilled at the 24th hour, with the increase of instill dose, the rate of apoptosis and necrosis in lung cell of rats showed dose-effect relationships . The rate of apoptosis and necrosis in high dose group was respectively 1.11,2.32 times higher than the control group. (3).There was a significant declining in the rate of pulmonary macrophage phagocytosis of rats of each sect time and concentration. Some effects of fine particles(PM2.5) in sand dust storm on the index of phagocytosis have been found in the pulmonary macrophage of rats, but there was no statically significance. With the increase of instill dose, the rates of neutrophil phagocytosis of rats declined. 2.Results of inhabitants' health survey:(1). The incidence of various diseases and symptoms of inhabitants and juveniles in district where sand dust storm frequently happened were found higher than that sand dust storm infrequently proceed, the incidence of pharyngitis, heart disease, neuralgia, arthritis were found to be respectively 6.5,4,6.65,2.28 times higher. Flu, chronic bronchitis, hypertension, heart disease, gastritis, arthritis were found to be strongly relevant with effective protecting measures during sand dust storm (2).The results of saliva lysozyme assay of juveniles showed that each section of juveniles of saliva lysozyme assay activity in territory sand dust storm frequently proceed were lower than that in district sand dust storm infrequently proceed. The influencing factors of salivary lysozyme were analysised by multiple regression analysis which showed the salivary lysozyme level was concerned with gender (X1), age (X2), time of daily outdoor activities during sand dust storm (X7).Conclusions: 1. Fine particles(PM2.5) in sand dust storm could cause oxidative damage in DNA of lung cells of rats, could weaken the phagocytosis function of alveolar macrophages and neutrophils. PM2.5 in Dust storm could impact the apoptosis and necrosis of lung cells of rats ,the greater the concentration of particulate matter, the more obvious would be the injury. 2. Sand dust storm can cause acute and chronic injury, and cumulative damage on the human. Sand dust storm can depree activity saliva lysozyme of juveniles, impair the non-specific immune function of juveniles. |
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