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Our present study emphasizes UVA radiation induced ET reaction as one of the key aspects of a potential carcinogen , benzo [ a ] pyrene ( BP ) , in the presence of a wide variety of molecules covering organic p - benzoquinone ( BQ ) , biological macromolecules like calf - thymus DNA ( CT - DNA ) , human serum albumin ( HSA ) protein , and inorganic zinc oxide ( ZnO ) nanorods ( NRs ) .
 benzo [ a ] pyrene, p - benzoquinone, zinc oxide, ZnO
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 benzo [ a ] pyrene, p - benzoquinone, zinc oxide, ZnO