1556
Overall , the present study , using a different and more sensitive statistical model than the parent study , revealed a statistically significant dose - dependent correlation between cumulative exposure to Hg from dental amalgams and urinary levels of GST - alpha , after covariate adjustment ; where as , a nonsignificant relationship was observed with urinary levels of GST - pi .
 Chemical: Hg
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: Hg