A message to doctors

Most cases of lead poisoning show no symptoms at the time the poisoning is occurring.

The NHMRC (National Health and Medical Research Council) recommends that no Australian should have a blood lead level above 0.48 µmol/L (10 µg/dL), and that there is a particular urgency in lowering blood lead levels in children under 4 years of age.

Lead poisoning is extremely common.

In a study by Prof. Michael Mira et al (MJA, 1996), of 718 children aged between 9 and 62 months living in Sydney, within 10 km of the Sydney CBD, 25% of the children had a blood lead level above 10 µg/dL, and 7% had a notifiable level ie, above 15 µg/dL.

Outside this radius, 9% of the children had a level above the national goal and 1.5% had a notifiable level. Overall, 17% of the children between 9 and 48 months were above 10 µg/dL and fully 19% or nearly one in five of the

At lead levels where damage is occurring, symptoms are usually NOT present.

children between 9 and 36 months were above 10 µg/dL. At 10 µg/dL, children in particular may be suffering a 2-3 point IQ loss, learning difficulties, kidney damage and other significant health impacts. These patients will not be displaying symptoms. However, there may be some symptoms at higher levels, and these vary according to blood lead levels. The table below shows the symptoms caused by moderate, severe and medical emergency levels of lead in the blood. If these symptoms are present in a patient with blood lead levels less than 2.17µmol/L (45µg/dL), then those symptoms are not due to lead poisoning.

If there is a risk factor, a venous blood lead test is essential.

Unfortunately capillary droplet (finger-prick) lead assessment is not available in NSW and any capillary sampling has a high risk of lead contamination. Venous samples remain the recommended sampling technique. Blood samples can be sent to your chosen pathologist – most of the private pathologists will send the sample on for lead assessment at a hospital or a larger private pathologist.