Pathology Handbook

Lead

Clinical Indications

Lead poisoning is a preventable condition that results from environmental exposure to lead; this exposure can result in permanent health damage, especially among children.  In the UK the main sources of lead exposure are air-borne lead (from industrial sources), water-borne lead (where lead dissolves readily from lead piping or from lead solder in water pipes, sometimes found in pre-1970s buildings), and occupational and hobby exposure (e.g. plumbers and stained glass artists).

Lead poisoning can affect almost all parts of the body, including the central nervous system, kidneys, and reproductive organs. It commonly causes weakness and abdominal discomfort and less often causes abdominal pain, vomiting, constipation, foot and wrist drop and anaemia.  In children especially, it impairs cognitive development, which can lead to learning disabilities and behavioural problems. At very high levels, it can even result in hallucinations, coma, seizures, and death.

Screening: Adults who work in industries known for lead exposure, for example plumbers, lead miners, shipbuilders, construction workers, demolition workers and pottery manufacturers should be screened for lead exposure. Adults who have hobbies that involve lead-based paints, ceramics, soldering etc should also be tested.

Diagnosis: Symptoms, including fatigue, changes in mood, nausea, headache, tremors, weight loss, or decreased libido, may be due to lead poisoning. The test may also be useful in investigation of patients for peripheral neuropathy, anaemia, reproductive failure, encephalopathy, or memory loss, which are symptoms of lead poisoning.

Request Form

Request on ICE or use combined Biochemistry/Haematology form

Availability

On request

Patient Preparation

No specific preparation required

Turnaround Time

2 weeks

Specimen

Whole blood (Lemon top Biochemistry EDTA tube)

Volume

5-10 ml (paediatric 2-5 ml)

Container

Vacutainer lemon top

Lab Handling

Sent to referral laboratory (Royal Surrey County Hospital)

Causes for Rejection

Unlabelled or incorrectly labelled sample; incorrect sample container

Reference Range

Blood levels

Environmental exposure:

Children:    < 0.5 µmol/L  [<10 µg/dL]

Adults:       <0.7 µmol/L   [<14 µg/dL] 

Industrial exposure:

<1.9 µmol/L [<40 µg/dL]: Repeat every 12 months

>1.9 µmol/L [>40 µg/dL]: Suspend female employees from work involving lead

1.9- 2.8 µmol/L [40-59 µg/dL]: Repeat every 6 months

2.9-3.3 µmol/L [60-69 µg/dL]: Repeat every 3 months

>3.4 µmol/L  [>70 µg/dL]: Employee unfit for work

Unit Conversion

To convert: µg/dL x 0.05 = µmol/L