3996
Morphometric analysis revealed an increase in the extent of emphysematous changes after 5 months of MS inhalation , which did not significantly change over the following 13 months of study duration , irrespective of whether MS exposure was continued or not .
 None
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:  
Answer:
 None