权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Inhalation Toxicity of Man-Made Mineral Fiber (MMMF)

人造矿物纤维的吸入毒性 (MMMF)

基本信息

批准号：
02454207
负责人：
TANAKA Isamu
金额：
$ 4.1万
依托单位：
University of Occupational and Environmental Health
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02454207/
关键词：
MMMF Glass Fibers Lung Deposition Inhalation

项目摘要

Pulmonary deposition and the clearance of deposited particles from lungs are very important factors to induce pneumoconioses and tumors.In this experiment, 42 Wistar male and 45 Wistar female rats were exposed to glass fiber (GB-100R, Advantec Toyo, Co., Japan) (content : SiO_2 63 %) for 6 hrs/day, 5 days/week for 4 weeks, and for chronic inhalation toxicity test, 27 Wistar male rats were also exposed to glass fiber for 1 year. The mass median aerodynamic diameter was 2.7 mum by an Andersen sampler, and the count median diameter and length determined by a scanning electron microscope were 0.51 mum and 5.5 mum, respectively. The daily average exposure concentration was controlled by a continuous fuluidized bed with a screw feeder and an overflow pipe at 10.8 <plus-minus> 3.3 and 9.8 <plus-minus> 3.0 mg/m^3 during the exposure period in the male group and female group for 4-week exposure, respectively and 2.2 <plus-minus> 0.6 mg/m^3 for 1-year exposure. The fibrous particle concentration … More s in the exposure chamber were monitored by a light scattering method and were constant during the exposure.The rats were sacrificed at 24 hours after 1, 2, 3 and 4 weeks exposure and after 3.5, 5.5, 6 and 12 months clearance period following a 4-week exposure. For chronic effect of glass fiber on lung deposition, they were killed just after the 1-year exposure and after 1 year clearance period following a 1-year exposure. The wet lung weight and the silica concentration in thelungs were measured and the lungs were treated for low temperature ashing (ca. 150 ﾟC) by using a plasma asher.After ashing, these samples were melted with sodium carbonate in a platinum pot to measure the silicon content by the absorption spectrophotometry.The amount of deposited silicon in rat lungs by exposure to glass fiber was calculated from the difference value of measured silicon content between the exposed rats and controls. The deposited amount of glass fiber which was observed up to 300 ug in the 4-week exposed male rats, was proportional to the exposure period. For chronic exposure, the deposited amount of glass fiber was observed 1.5 mg and 0.6 mg after the 1-year clearance just after 1-year exposure. The apparent deposition fraction which is defined as the deposited amount in the lungs to the amount of the inhaled glass fiber during the exposure, was 4.5 % and 4.7 % in male and female, respectively. There was no significant difference in the apparent deposition fraction between male and female rats.During the clearance period, the deposited silicon content decreased with the increasing of the clearance period. The biological half time in the one-compartment model was determined to be 1.5 months in male and female rats ; for 4-week exposure, but 9.2 months for 1-year exposure. The biological half time increased with the increasing of the exposure period. The cause of this may be decrease of clearance activity by fiber deposition, however, there were no malignant tumor in this experiment. 10. KEY WORDS Less

在本实验中，将42只Wistar雄性和45只Wistar雌性大鼠暴露于玻璃纤维（GB-100 R，Advantec Toyo，Co.，日本）（内容：SiO_263%）连续暴露6小时/天，5天/周，共4周。质量中值空气动力学直径为2.7妈妈由安德森采样器，和计数中值直径和长度由扫描电子显微镜测定分别为0.51妈妈和5.5妈妈，分别。采用带螺旋给料机和溢流管的连续流化床，将接触期内的日平均接触浓度控制<plus-minus><plus-minus>在：男组4周为10.8 ± 3.3 mg/m^3，女组为9.8 ± 3.0 mg/m^3<plus-minus>; 1年为2.2 ± 0.6 mg/m^3。纤维颗粒浓度 ...更多信息在暴露1、2、3、4周后24小时和暴露4周后3.5、5.5、6、12个月的清除期后处死大鼠。对于玻璃纤维对肺沉积的慢性影响，在1年暴露后立即处死，并在1年暴露后的1年清除期后处死。测量肺湿重和肺中二氧化硅浓度，并对肺进行低温灰化处理（约10 ℃）。用等离子灰化器（150 ℃）灰化，灰化后在铂锅中用碳酸钠熔融，用吸光光度法测定硅含量，根据测定的暴露大鼠与对照组大鼠肺中硅含量的差值计算暴露大鼠肺中硅沉积量。在暴露4周的雄性大鼠中观察到高达300 ug的玻璃纤维沉积量与暴露时间成比例。对于慢性暴露，在暴露1年后立即清除1年后，观察到玻璃纤维沉积量为1.5 mg和0.6 mg。表观沉积分数定义为暴露期间肺中沉积量与吸入玻璃纤维量之比，男性和女性分别为4.5%和4.7%。在清除期内，随着清除时间的延长，硅沉积量逐渐减少。在单室模型中，雄性和雌性大鼠的生物半衰期确定为1.5个月; 4周暴露，但1年暴露为9.2个月。生物半衰期随暴露时间的增加而增加。其原因可能是纤维沉积降低了清除活性，但本实验中没有发现恶性肿瘤。10.关键词减