The effect of magnetic fields on platelets, blood coagulation and fibrinolysis in guinea pigs.

Exposure of guinea pigs to homogeneous magnetic fields as low as 0.005 T for 1 hour, 7 days a week, for 6 weeks led to a decreased platelet count; increased platelet aggregation; increased prothrombin and partial thromboplastin times; decreased fibrinogen and increased fibrinolysis. These effects were reversible within 2 months of discontinuation of exposure to the magnetic field. These results suggest an extensive hemorrhagic diathesis combined with a tendency toward thrombosis. Possible mechanisms are discussed.