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Immortalized human bronchial epithelial cells ( 16HBE14o - ) were exposed to 0 , 130 , or 330nM arsenic ( as Na - arsenite ) for 4 - 5 weeks and examined for wound repair efficiency and ATP - mediated Ca ( 2 + ) signaling .
 Chemical: arsenic; Chemical: Na - arsenite; Chemical: ATP; Chemical: Ca ( 2 + )
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: arsenic; Chemical: Na - arsenite; Chemical: ATP; Chemical: Ca ( 2 + )