More than 200 American Red Cross workers in Michigan went on strike this morning.
Staff members represented by the Office and Professional Employees International Union Local 459 and Teamsters Local 580 walked out because of a dispute over health care benefits.
The strike affects blood collection centers in Kalamazoo, Jackson, Lansing, Flint and parts of northern Michigan.
Monica Stoneking is communications manager for the Great Lakes Region of the American Red Cross.
She says the strike will impact an already-low blood supply.
"That's about 700 units of blood every day that the Great Lakes region needs to collect," Stoneking says. "And if our staff members are on strike, we are limited as to the number of blood drives we are able to hold."
Stoneking says blood donations are also lower because fewer people donated during Michigan's recent nice weather, because students have been been on spring break.
