4479
The aim of this study was to evaluate the bioavailability of arsenic ( As ) through cultured oyster Crassostrea gigas and Crassostrea corteziensis from four coastal lagoons ( SE Gulf of California ) .
 Chemical: arsenic; Chemical: As
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: arsenic; Chemical: As