RESUMO
Objective To survey free crystalline silica[SiO_2(F)]content,particle size and water-soluble components concentration in the sand-dust storm dust,in order to prevent large-scale non-occupational silicosis(desert lung) prevalence in northwest desert area of China.Methods Atmospheric dust(falldust) were collected in Hetian,Minqin,Zhongwei and Lanzhou city when sand-dust storm befallen and free crystalline silica,particle size ratio and water-soluble components were analyzed according to GB 5748—1985.Results The rate of SiO_2(F) component was over 50%in the original sand,the rate of SiO2(F) component was from 17.36% to 48.09%in the falldust of sand-dust storm,the falldust belongs to crystal dust.The inhaleble particle(particles with amedian diameter of 0.5-10?m) ratio was from 63.3%to 84.1%.The water-soluble components concentration increased as sand-dust storm moving.C1,SO_4~(2-) and NO_3~- content was from 220?g/g,870?g/g and 230?g/g of Hetian to 980?g/g,5 400?g/g and 1 400?g/g of Lanzhou(P
RESUMO
Objective To study the effects of PM2.5 and PM10 of dust storm on the secretion of nitrogen oxide(NO), interleukin-8 (IL-8) and tumor necrosis factor-?(TNF-?)in the alveolar macrophages(AM)of rat in vitro. Methods PM2.5 and PM10 were collected during dust storm period in the urban area of Beijing. The tested cells were primary cultured alveolar macrophages. Cytotoxicity of the particles was measured by MTT assay. The content of NO was determined using Griess reagent. The levels of cytokines IL-8 and TNF-? were determined using radioimmunity assay. Results After treatment for 24 h, PM2.5 and PM10 caused cytotoxicity to AM and the survival rate of the cells was decreased with the increasing exposure dose of the dust to the rats and the survival rate of the cells in the high dosage group was 80% of the control group. At concentrations of 20～150 ?g/ml, PM2.5 and PM10 increased the secretion of NO, TNF-? and IL-8 in AM in a dose-dependent manner. The cytotoxicity of PM2.5 was stronger than that of the PM10 at the same concentration, while the effects on the increasing secretion of NO, IL-8 and TNF-? induced by PM2.5 was smaller than that of the PM10. Conclusion PM2.5 and PM10 of dust storm could induce the secretion of inflammatory factors NO, IL-8 and TNF-? in rat AM.
RESUMO
Objective To investigate the genetic damage of dust storm fine particles on human blood lymphocytes. Methods The chromosomal aberration test and cytochalasin B blocked test were used to investigate the effect in vitro of dust storm fine particles (PM2.5) (0, 33, 100, 300 ?g/ml)collected in Baotou and Wuwei cities on human lymphocytes. Results In both dust storm and normal ambient air fine particles treated cells revealed an increase in the chromosomal aberration level and micronuclei frequency (MNF). The chromosomal aberration(CA)were characterized as chromatid break, chromosome break, acentric fragment, dicentric chromosome and gaps. With the increase of treatment concentrations the aberration level and MNF increased and the mitotic index(MI) and the nuclear division index (NDI) values declined in a dose-response manner(P0.05). The treatments of normal ambient air PM2.5 from Baotou City were significant higher than those of Wuwei City, but the treatments of dust storm PM2.5 were not significant different between the cities. Conclusion Dust storm PM2.5 from Baotou City and Wuwei City may cause human lymphocytes genetic damage and its genetic toxicity is related to the dose.
RESUMO
Objective To make it clear whether dust storms may produce same acute adverse impacts on community population. Methods 2 primary schools in Baotou City were selected. During the period of dust storm in March of 2004 an investigation among 918 pupils from third to fifth grades and 1 770 parents of them was conducted by questionnaires. Meanwhile the concentrations of PM2.5 were also determined. Results On the day of dust storms developed the concentrations of PM2.5 obviously increased (212.9 ?g/m3)then decreased rapidly(