20074
A total of 42 pre - migrating ( silver ) female eels from lowly , highly and extremely polluted environments in Belgium and , for comparative purposes , a lowly polluted habitat in Italy were measured for polychlorinated biphenyls ( PCBs ) , organochlorine pesticides ( OCPs ) and brominated flame retardants ( BFRs ) .
 Chemical: polychlorinated biphenyls; Chemical: PCBs; Chemical: organochlorine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: polychlorinated biphenyls; Chemical: PCBs; Chemical: organochlorine