More and more Transportation Safety Administrators call for work as government closure continues and forces them to work without pay CNN.

A federal worker pay period ended FridayThis means that workers could start to miss paychecks if the closure continues. They were paid last week and should normally be paid again on January 11th.

How many? Different airports have experienced different levels of increasing absences. TSA's employee union president, Hydrick Thomas, said 170 employees have been calling every day this week at John F. Kennedy International Airport in New York.

A Texas TSA official said incoming calls had increased by 200 to 300 percent at the Dallas-Fort Worth International Airport. North Carolina TSA union president Mac Johnson said Charlotte and Raleigh-Durham airports had 10% more extra calls and absences "created a vulnerability."

Why are they calling? Some federal officials told CNN that the absences were a protest against late payments. Others have said that some TSA employees can not go to work because they can not afford child care during the closure or because they have had to find a temporary job non-governmental to pay their bills.

"The problem of incoming calls will really explode over the next two weeks when employees miss their first salary," a DFW union official told CNN. "TSA agents tell the union that they will find another way to make money, which means calling for other jobs."

What is the impact? TSA spokesman Michael Bilello said the absences had not yet caused significant disruption in the TSA's ability to assume security functions.

"Incoming calls started during the holiday period and have increased, but have minimal impact as 51,739 employees support the filtering process," Bilello said in a statement. "The effectiveness of safety will not be compromised and performance standards will not change."

Bilello said that additional absences in the coming days and weeks could result in longer lines, as some airports may have to close some tracks of the TSA.

Thomas said that he thought the closure and the resulting absences would impact travelers.

"This will definitely affect the flying public we want to protect," said Thomas.