Observations on the mechanical fragility of the red cell in 68 workers having had exposure to lead in varying degrees, and on blood to which lead had been added in vitro in concentrations up to 5μg./ml., showed that the mechanical fragility index did not vary significantly from that of a control group.
Furthermore, the use of various anticoagulants produced no significant alterations in the mechanical fragility index. It was found, however, that in subjects suffering from anaemia of varying types, the mechanical fragility index was always greatly increased if the haemoglobin was below 80%.