Classes to resume at Estabrook as PCB levels decline

By Sara Brown and Katrina Ballard, Globe Correspondents

Classes will resume Monday at the Joseph Estabrook Elementary School in Lexington as school officials decided Friday that levels of polychlorinated biphenyls, or PCBs , have been reduced to a safe level.

The unanimous decision came as results from tests on 18 air samples at the school showed that levels of the toxic chemical "have improved substantially," said Superintendent Paul Ash in a memo to Estabrook parents. He said flushing air into the school and modifying ventilation systems were responsible for the improvement.

The test results and other aspects of the PCB situation at the school were considered by an advisory committee composed of Estabrook parents, school officials and a representative from the school system's environmental consulting firm.

According to Ash's memo, the school will take precautions when it opens Monday, including additional air sample tests to ensure that PCB levels continue to decline. Extra ventilation will be added to the four kindergarten classrooms to reduce levels to EPA-recommended targets, with a back-up option of shifting kindergarten classes to the Central Administration office.

A crew from an environmental consulting firm crew has worked to encapsulate the caulking around panels below classroom windows at the school after test results released earlier in the week showed high PCB levels in the caulking material. Ash said Friday that all the caulk surrounding the interior side of panels below the windows have been encapsulated and ventilators have been inspected and cleaned.

Students did not attend classes at Estabrook this week after tests last month showed PCB levels in the air that were above the federal standard. Classes were cancelled Tuesday and students had Thursday off because of the Rosh Hashanah. They went on field trips Wednesday and Friday.

Tests last spring found that the school had potentially unsafe levels of the chemicals in the building’s caulking, and work to remove them began Aug. 24, said Gerard Cody, the town’s health director.

The removal was to be completed before the first day of classes on Aug. 31, but town inspectors measured even higher levels of PCBs in some of the building’s rooms.

Estabrook was closed last week to allow crews and consultants to continue the second phase of PCB removal after taking out contaminated window caulking did not lower the chemical levels.

PCBs are believed to harm the immune and reproductive systems. Studies have linked them to cancer, according to the EPA.