<P> Despite betrayal of the secret to the meat packers , who worked three shifts a day for three weeks to thwart the inspection , Neill and Reynolds were still revolted by the conditions at the factories and at the lack of concern by plant managers ( though neither had much experience in the field ) . Following their report , Roosevelt became a supporter of regulation of the meat packing industry , and , on June 30 , signed the Meat Inspection Act of 1906 . </P>
what was the cause of the meat inspection act
conditions at the factories and at the lack of concern by plant managers