国际癌症研究机构(IARC)--- 二氧化钛（钛白粉）结论评估
（摘要）
5.2试验中的致癌性数据
二氧化钛致癌试验是通过给一组小鼠和一组大鼠口服进行的，两组大鼠的吸入，一组仓鼠气管内服入，一组大鼠皮下注射，一组雄性鼠和两组雌性鼠腹膜服入。增加入射肺脏腺瘤两种性别大鼠，诊断膀胱角质化作为鳞片细胞癌，观察在动物吸入大量低服量二氧化钛。任何品种口服、皮下注射、气管服入、腹膜进入均没有造成任何类型肿瘤病发率的提高。仓鼠气管进入的二氧化钛结合苯并[a]芘远远超过单独使用苯并[a]芘对喉部、气管和肺脏良性和恶性肿瘤控制治疗。
5.3人类致癌数据
现存有价值的流行病学的研究提供的是不确定的结果。
5.4 其他相关的数据
二氧化钛不会引发哺乳类细胞形态方面的转变或细菌的突变。
5.5 评论
没有充分的证据说明二氧化钛对人体有致癌作用。
全面评价：
二氧化钛不列为人体致癌物。
TITANIUM DIOXIDE
For definition of Groups, see Preamble Evaluation.
VOL.: 47 (1989) (p. 307)
CAS Nos.: 13463-67-7 - Titanium dioxide; 1317-70-0 - Anatase titanium dioxide; 1317-80-2 - Rutile titanium dioxide
Chem. Abstr. Name: Titanium dioxide
5. Summary of Data Reported and Evaluation
5.1 Exposures
Titanium dioxide is a white pigment produced mainly from ilmenite (iron titanate) and natural rutile (titanium dioxide). It is widely used in paints, paper, plastics, ceramics, rubber, inks and a variety of other products. Occupational exposure to titanium dioxide during its production, the production of paints, in painting trades and during other industrial use is likely to be extensive, but there is a paucity of data on levels, both occupational and environmental.
5.2 Experimental carcinogenicity data
Titanium dioxide was tested for carcinogenicity by oral administration in one strain of mice and in one strain of rats, by inhalation in two strains of rats, by intratracheal administration in one strain of hamsters, by subcutaneous injection in one strain of rats and by intraperitoneal administration in one strain of male mice and two strains of female rats. Increased incidences of lung adenomas in rats of both sexes and of cystic keratinizing lesions diagnosed as squamous-cell carcinomas in female rats were observed in animals that had inhaled the high but not the low doses of titanium dioxide. Oral, subcutaneous, intratracheal and intraperitoneal administration did not produce a significant increase in the frequency of any type of tumour in any species. Intratracheal administration of titanium dioxide in combination with benzo[a]pyrene to hamsters resulted in an increase in the incidence of benign and malignant tumours of the larynx, trachea and lungs over that in benzo[a]pyrene-treated controls.
5.3 Human carcinogenicity data
The only available epidemiological study provided inconclusive results.
5.4 Other relevant data
Titanium dioxide did not induce morphological transformation in mammalian cells or mutation in bacteria.
5.5 Evaluation
There is inadequate evidence for the carcinogenicity of titanium dioxide in humans.
There is limited evidence for the carcinogenicity of titanium dioxide in experimental animals.
Overall evaluation
Titanium dioxide is not classifiable as to its carcinogenicity to humans (Group 3).
For definition of the italicized terms, see Preamble Evaluation.
