2409
Previous studies have shown some potential for toxicity for tread particles , however , toxicity studies of TRWP collected from a road simulator system revealed no acute toxicity to green algae , daphnids , or fathead minnows at concentrations up to 10 , 000 mg / kg under conditions representative of receiving water bodies .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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