Updated

Excessive levels of a deadly carcinogen — linked to an incurable lung disease — were found at the New York City Second Avenue subway construction site during a federal safety inspection, according to documents obtained by The New York Post.

An air sample taken underground at East 69th Street and Second Avenue found more than three times the permissible levels of silica, tiny but dangerous dust particles dredged up during drilling construction, according to the Occupational Safety and Health Administration.

That sample was taken during an OSHA inspection Nov. 9, the results of which were released last week to Upper East Side Assemblyman Micah Kellner.

Overexposure to silica — which has been classified as a human lung carcinogen — can lead to silicosis, a lung disease with no cure that is common among construction workers.

The chronic disease can be fatal.

The three joint contractors at the site — Schiavone, Shea and Kiewit — were ordered to pay a $4,250 fine for the high silica levels, which OSHA deemed a “serious” safety violation.

They were also fined another $4,250 for failing to ensure that workers’ face masks — meant to keep the silica out of their lungs — fit properly.

The contractors have until April 20 to appeal OSHA’s findings.

Despite the disturbing results, the MTA insisted that the community — which has been complaining for months about air quality around the site — was never in danger.

“The levels of silica underground noted in these preliminary findings under no circumstance impacts air quality at street level,” said MTA spokesman Kevin Ortiz.

“Silica does not float in the air but rather drops to the ground, so it is essentially impossible for it to impact the air quality at the street level 100 feet above.”

Only one worker was exposed to the high silica levels, and that was because his face mask did not fit properly, said Ortiz.

Click here to read more from the New York Post.