1795
Current thinking suggests that exposure to toxicants found in cigarette smoke may be responsible for this elevated disease likelihood , and this gives rise to the idea that reductions in the levels of some smoke toxicants may reduce the harm associated with cigarette smoking .
 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