KANSAS CITY, Missouri - An earlier audit of the GSA found the group operated a weak environmental program that was incapable of determining whether conditions prior to 2010 were safe.
NBC Action News found more than 400 Bannister Federal Complex employees that became sick, some of them died.
There are two parts to the facility. One houses government offices and the other makes parts for nuclear bombs. A wall separates the two sides. Behind a set of double doors you'll find a hallway that's leads to a plant where Honeywell contractors are making parts for nuclear bombs.
The GSA and the EPA have placed air quality monitors in the areas where the two sections connect and where employees from both sides meet, like the cafeteria.
"We are doing some air sampling today for beryllium and uranium," said EPA spokesperson David Bryan.
The agency are testing to determine if workers on the GSA side are being exposed to toxins.
"This is only part of larger environmental work that we are going to see out here. We're going to be doing work out here over the next year to get a good characterization over an entire year," Bryan.
Some employees believe this should have been done sooner. The GSA admits testing should have been looked at in the past.
"Historically GSA could have done more and now we are taking those extra steps that we need to," said GSA spokesperson Angela Brees.
Brees has worked at the site for 3 years. The communication specialist is also pregnant with her first child.
"I do think it's safe to work here I come to work here daily as do 2,000 other people," said Brees.
The GSA also brought in the National Institute for Occupational Safety and Health. They are looking at how toxins might be passed between the two buildings.