13450
We also explored if mono - or combinational chelation therapy prevents arsenic - induced ( 25ppm in drinking water for 4 months ) neuronal apoptosis in a guinea pig animal model .
 Chemical: arsenic
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