23643
The model was extended to describe perchlorate , an environmental and food contaminant , that competes with the sodium iodide symporter protein for thyroidal uptake of iodide .
 Chemical: perchlorate; Chemical: sodium iodide; Chemical: iodide
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: perchlorate, sodium iodide, iodide 
Answer:
 Chemical: perchlorate; Chemical: sodium iodide; Chemical: iodide