How Times Have Changed

by Fred Salome, CTI Consultants Pty Ltd.

The picture of a lead poisoned painter shown here was found in "The Disease of Occupations" by Donald Hunter, first published in 1955.

In the section dealing with occupational lead poisoning, the 1975 edition contains a statement from a number of eminent doctors published in the British Medical Journal in 1968 to promote greater awareness of lead poisoning. In a table accompanying this statement these doctors gave their interpretation of blood lead levels, with a "normal" blood lead level being regarded (in 1975) as  <40 µg/dL, "acceptable" levels as 40-80 µg/dL and "dangerous" levels were considered to be  >120 µg/dL.

These compare with the present day NH&MRC "level of concern" of 10 µg/dl. Occupational blood lead levels > 40 µg/dL are now considered unsafe and removal from lead tasks is required at 50 µg/dL or more. 

Such radical changes over a period of less than 30 years reflect the increased scientific advance for the adverse health effects of what was once considered low level lead poisoning.