The results suggested that the kidney may be a main target organ of exposure to nano-TiO2 through different routes into the body. Lung toxicity Adverse health effects of air pollution have been recognized in epidemiological studies, and it was found that ultrafine particles PX-478 have been linked with pulmonary toxicity [74]. Here we focus on the pulmonary toxicity of exposure to nano-TiO2. Published articles about lung toxicity were obtained, and the available evidence supports that the percentage

of positive studies is higher than other groups: 79% studies from the content of Ti in lung (Table  6), 50% from coefficient of lung (Table  6), and 71% from the combining effects by different exposure routes (Table  7). Brain toxicity Metal oxides have been extensively studied, because of their toxic effects on humans and their utility in the study of the nervous system (NS). For a review dedicated entirely to the toxicity of metal oxides, the reader is referred to [4, 70, 73]. In the following discussion, we focus on the most important organ, the brain, in the nervous system for nano-TiO2 exposure. Overall, the number of brain toxicity

paper was very limited regarding the exposed nano-TiO2 by GSK3326595 solubility dmso various routes. Four studies suggested that the contents of Ti increased at different exposure time (Table  6) and the coefficient of brain changed slightly (Table  6). According to Table  7, the results illustrated that the percentage of positive studies reached in 80%, but this is only based on a small number of studies. Heart toxicity Cardiovascular toxicology is concerned with the adverse effects of extrinsic and intrinsic stresses on the heart and vascular system. A limited number of studies have been conducted to determine the impact of nano-TiO2 particles within in vivo models of heart toxicity. However, the findings suggest that nano-TiO2 through different exposure

routes Oxymatrine is deposited in the heart and contribute to inflammatory response and change in the enzyme activities which leads to heart toxicity. Grouping of the studies with heart toxicity revealed that the percentage of positive studies was lower than other groups about Ti content, coefficient, and combined effects by different routes (Tables  6 and 7). Conclusion and discussion Evaluating the hazards associated with nano-TiO2 is vital for risk assessments. Numerous articles from experiments have been reported in the literature on the relationship between exposure to nano-TiO2 and health consequences, but no coherent results have emerged from different articles. To reveal possible consistent patterns, 62 papers were collected and the data was analyzed by systematic comparison of the study characteristics between positive and negative studies.