Study on the Carcinogenic Potential of JFM Standard Fibrous Materials in F344 Rats after Intraperitoneal Administration.

12种类型的纤维样本（JFM standard）被评价为女性F344 rats two Years after the intraperitoneal administration。Peritoneal mesothelioma were induced in the rats administered silicon carbide whisker （SC）、UICC chrysotile B （UC）、potassium titanate whisker（PT）、ceramic fiber 1（RF1）、ceramic fiber 2（RF2）或aramid fiber（AR）。在大鼠暴露于多纤维（RF 3）、wollastonite （WO）、rockwool （RW）、玻璃wool（GW）、TiO 2 whisker （TO）或微玻璃纤维（MG）中没有明显的长效应和肿瘤指示。患有穿孔性间皮瘤的老鼠被发现很容易通过血液运动的累积而被发现。肿瘤细胞在底部壁形成小节点（1至3毫米φ）上产生了差异。在大多数间皮瘤病例中，糖尿病和肝脏被观察到的粘合剂。任何老鼠中都没有肿瘤的变形症可以遥控器官或组织。历史性的、辛辣的类型和混合的类型更常见 ... More 一种基本的类型。在这些间皮瘤中，6%展示了肿瘤的缺失差异。基于这些结果，我们试图评估人造纤维在比较中的碳原潜力。因为UC的剂量在逻辑上微观上与50%的存活期（对间皮瘤）反向生长，UC可以通过SC和PT的50%的存活期计算相等剂量。当UC、Sc和PT纤维的数量和重量比相同时，估计呼吸空气中含有1.3 × 10 × D1 - 6 × D1纤维/ml （世卫组织）或4×10 × D1- 6 × D1纤维/ml （EPA）的石棉寿命将导致1 000，000，000的癌症有一个终生风险，0.5 X 10-D1 fiber/ml （WHO） or 1.7 X 10-D1 fiber/ml （EPA） of SC and 5.7 x 10-D1 fiber/ml （WHO） or 1.7 x 10-D1 fiber/ml （EPA） of PT have equal risk。根据工作环境的规定， 0.2纤维/毫升的石棉具有可暴露限值（PEL-OSHA），SC的含量等于0.09纤维/毫升，PT的含量为0.90纤维/毫升。阈值限值（TLV-ACGIH）为0.5纤维/ml，纤维/ml的水平等于0.21纤维/ml的SC或2.2纤维/ml的PT。Less（低）

Carcinogencity of 12 types of fibrous samples (JFM standard) was evaluated by the incidence of peritoneal mesothelioma in female F344 rats two years after the intraperitoneal administration. Peritoneal mesothelioma were induced in the rats administered silicon carbide whisker (SC), UICC chrysotile B (UC), potassium titanate whisker(PT), ceramic fiber 1(RF 1), ceramic fiber 2(RF2) or aramid fiber(AR). No significant lethal effect and tumor induction was observed in rats exposed to mullite fiber (RF3), wollastonite (WO), rockwool (RW), glasswool (GW), TiO2 whisker (TO) or micro glass fiber (MG). The rat having peritoneal mesothelioma was found easily by the accumulation of bloody ascites. Tumor cells diffused on abdominal wall forming small nodules (1 to 3 mmφ). Adhesive proliferations between diaphragm and liver were observed in most mesothelioma case. There was no metastasis of tumor to remote organ or tissue in any rats. Histopathiogically, sarcomatous type and mixed type were more th … More an the epithelial type. Among these mesotheliomas, 6% showed the osseous differentiation of tumor.Based on these results, we tried to evaluate the carcinogenic potency of man-made fibers in comparison with UC. Because the dose of UC was logarithmically in inverse proportion with 50% survival period (due to mesothelioma), equivalent dose to UC could be calculated by the 50% survival period of SC and PT. When the number and weight ratios of UC, Sc and PT fibers are same, it is estimated that breathing air containing 1.3 X 10ィイD1-6ィエD1 fiber/ml (WHO) or 4×10ィイD1-6ィエD1 fiber/ml (EPA) of asbestos for entire life will result one life time risk for cancer in 1,000,000, identically, 0.5 X 10ィイD1-6ィエD1 fiber/ml (WHO) or 1.7 X 10ィイD1-6ィエD1 fiber/ml (EPA) of SC and 5.7x 10ィイD1-6ィエD1 fiber/ml (WHO) or 1.7x 10ィイD1-6ィエD1 fiber/ml (EPA) of PT have equal risk. On the regulation of working environment, 0.2 fiber/ml of asbestos is the permissible exposure limit (PEL-OSHA) and is equal to 0.09 fiber/ml for SC and 0.90 fiber/ml for PT. Threshold limit value (TLV-ACGIH) is 0.5 fiber/ml for asbestos and the level is equivalent to 0.21 fiber/ml for SC or 2.2 fiber/ml for PT. Less