19170
Titanium dioxide nanoparticles ( TiO2 NPs ) are massively produced and widely used in daily life , which may pose potential risk to human health via uncharacterized interaction between DNAs .
 Titanium dioxide, TiO2
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Titanium dioxide, TiO2