Ongoing renovations to better connect BWI Thurgood Marshall Airport's concourses have uncovered asbestos and mold, and airport officials expect more could be found in the future.
The discovery of the materials has not presented a danger to fliers or workers or slowed down the work, said Jonathan Dean, an airport spokesman. But it has increased the price tag.
On Wednesday, the state's Board of Public Works will consider adding $100,000 to an existing $180,000 contract to cover the abatement costs of "unexpected" asbestos and mold found during work on the Maryland Aviation Administration's new, $113 million B and C concourse connector.
That connector was completed last year, though some mold abatement is still required, according to an outline of the proposed funding increase.
The increase will also allow for "contract continuity" with Landover-based abatement contractor SanDow Construction Inc. in case more asbestos or mold is found as the airport begins its separate, $125 million project to connect its D and E concourses.
That connector will create two "swing gates" between the concourses that the airport will be able to use for domestic or international flights, thus increasing its international capacity just as its largest carrier, Southwest Airlines, eyes continued expansion into the overseas market.
Asbestos was commonly used in construction in past decades, before its harmful health effects were fully known. Today, handling without proper safety equipment is avoided because of links to several life-threatening illnesses, including lung cancer and mesothelioma, according to the Centers for Disease Control and Prevention.
Certain mold species can produce toxins or are considered human pathogens that can cause infections, according to the CDC.
Dean said some parts of the airport renovated under the B and C connector work dated back to the late 1940s, when BWI was constructed as Friendship International Airport. Part of the D concourse where it connects to the terminal dates to the same time.
The airport was renamed Baltimore/Washington International Airport in 1973, a year after the state purchased the airport from Baltimore. The airport was nearly doubled in size in 1979, and has experienced many other renovations since.
In fiscal 2014, about 22.2 million passengers flew through BWI, more than flew through either Washington Dulles International Airport or Reagan National Airport, the region's other two major airports.
Dean said as the airport continues to renovate its facilities, it will "occasionally encounter" asbestos and mold — but the work has not presented a danger to fliers, airport employees or contractors and won't moving forward.
"When the material is discovered, it must be mitigated by professional contractors," he said. "There are specific standards and guidelines that these professionals work to meet."
Ensuring that those standards are met is the "reason for the contracts" before the BPW, he said.
"The firms work to ensure a safe environment at BWI during the major construction."