A backlog of hundreds of tissue samples taken from patients who were tested for cancer is waiting to be processed at the Eric Williams Medical Sciences Complex, Mt Hope, after concerns about poor ventilation of cancer-causing chemicals forced a pathology laboratory to be shut down last month.

TV6 News obtained exclusive access to the Mt Hope hospital's histology laboratory, which is crammed with tissue specimens, some in used plastic water bottles, waiting to be processed.

Technicians employed in the lab say the samples are preserved in formaldehyde, a carcinogenic or cancer-causing chemical compound used to preserve human tissue.

The employees said the 12 technicians who work there have been inhaling fumes from the formaldehyde since the extraction fan, which pulls air out of the lab, broke down last month.

Chief executive officer of the North Central Regional Health Authority (NCRHA) Colin Bissessar confirmed the hospital closed the lab on June 24.

The workers said patients are now forced to take their samples to private health institutions or laboratories and pay for the specimens to be analysed in order to get a diagnosis.

Responding to the workers' concerns, Bissessar said the ventilation system in the histology lab has been repaired, but the lab remains closed because Caribbean Industrial Research Institute (Cariri) must conduct additional tests on the air quality before the workers can return.

He also says the hospital is actively looking for two pathologists to process the backlog of tissue specimens and will send emergency cases to other regional health authorities for analysis.

Bissessar said he was not aware of complaints from three pregnant employees about health challenges arising in recent weeks, but he said the 12 lab technicians have been transferred to other labs in the interim.

He said the NCRHA board of directors will be meeting to address quality concerns, and he said the chief medical officer is in possession of a preliminary report from Cariri.