18723
Both of these particulate substances lead to severe lung toxicity that might impair oxygen uptake , but testicular toxicity is only observed with GaAs .
 Chemical: oxygen; Chemical: GaAs
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: oxygen; Chemical: GaAs