The 24-year Navy veteran decided to part with his waist-length hair Jan. 18.
USAMRIID scientists have helped with the research behind vaccines and treatments for diseases like Ebola or tularemia.
One of the concerns was the Army Medical Research Institute of Infectious Diseases's effluent waste decontamination system.
Sen. Chris Van Hollen wrote that he was deeply concerned about the halt to research at the military laboratory.
Plaintiffs seek $750 million for harm and death caused by exposure to hazardous materials from Fort Detrick.