The arrests Friday were part of a seven-month investigation by the Port Authority inspector general and the site's integrity monitor, spokesman Steve Coleman said.
WNBC-TV, New York, noted several undercover drug purchases were made from the suspects.
"There is no place at the World Trade Center site for those who want to use or sell illegal drugs, thereby endangering their co-workers and the public. We will not tolerate this behavior," said Port Authority Executive Director Pat Foye in a statement.
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