18698
The comet assay revealed significantly higher DNA damage levels ( 2 - to 6 - fold higher ) in treated amphipods compared to untreated ones with a sublethal concentration of 17 . 6 % of the WSF within 72 h of treatment .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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