3552
Although in the present study population PCB - 153 , DDE and HCB exposure increased within the first months of postnatal life , no associations were found between different periods of postnatal exposure to these compounds and mental or psychomotor scores .
 Chemical: PCB - 153; Chemical: DDE; Chemical: HCB
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: PCB - 153; Chemical: DDE; Chemical: HCB