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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.
| Lead poisoning symptoms at a glance |
|
Moderate 2.17 to 2.65 µmol/L
(45 - 55 µg/dL)
Muscle pains
Prickly, itchy feeling
Mild fatigue
Aggressiveness
Irritability
Lethargy
Abdominal discomfort |
Severe 2.65 to 3.38 µmol/L
(55- 70 µg/dL)
Joint pains
General fatigue
Poor concentration
Tremor
Headache
Abdominal pain
Constipation
Weight loss |
Medical Emergency >3.38 µmol/L
( >70 µg/dL)
Partial paralysis
Paralysis
Brain swelling
Stupor or coma
Fits and vomiting
Gum lead line
Colic
Death |
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