Lead

The lead test is used to evaluate the concentration of lead in your blood to determine if you have been exposed to harmful levels.

Blood lead is monitored in workers whose environment contains lead.In Australia the main sources of lead exposure are air-borne lead (from industrial sources and from the use of lead in petrol), and occupational and hobby exposure (e.g. plumbers and stained glass artists).

For screening: Blood lead tests may be ordered to screen people in the workplace if lead contamination is a potential problem. This testing conforms to Health and Safety Executive rules for occupational exposure.
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. For a list of hobbies that may expose you to potentially high levels of lead, go to lead poisoning.

The NHMRC guidelines for lead level interpretation are:

Desirable goal for individuals with no workplace exposure

• Levels less than 0.48 umol/L (10.0 ug/gL)

Workplace exposure
Immediate removal from exposure is necessary if the levels are greater than or equal to:

• 2.42 umol/L (50 ug/dL) for males and females not of reproductive capacity
• 0.97 umol/L (20 ug/dL) for females of reproductive capacity
• 0.72 umol/L (15 ug/dL) for females pregnant or breastfeeding.

For diagnosis: The test can help determine whether symptoms, including fatigue, changes in mood, nausea, headache, tremors, weight loss, or decreased libido, are due to lead poisoning. The test may also be needed if a patient has peripheral neuropathy, anaemia, reproductive failure, encephalopathy, or memory loss, which are symptoms of lead poisoning.

The higher the test result, the more lead is in your system and the more potential danger there is to your health. Guidelines and recommendations for treatment differ for children and adults.

Most experts agree that at a very high blood lead concentration, above 3.5 - 4.0 µmol/L (70 - 80 µg/dL), a person is at the medical emergency level and should get immediate medical attention. This may include chelation therapy if the blood levels are very high. Abatement - removing the source of the environmental exposure to lead - must also be done. Most also agree that adults and children with blood concentrations of less than 0.5 µmol/L (10 µg/dL) are not lead poisoned, and further testing is not necessary unless they are exposed again.

Children are more susceptible to lead poisoning than adults and so in children lead levels should not exceed 0.5 µmol/L (10 µg/dL). Children who have blood concentrations just under the emergency cutoff of 3.5 µmol/L (70 µg/dL) or higher should be treated and tested again within 24 hours.

Any child who has an elevated blood lead level needs to have their home or other environment evaluated. Other people at the residence should be tested as well. Without treatment or abatement of the environmental cause, the elevated lead level will likely recur.

Poisoning with lead is more harmful for children, whose brains and other organs are still developing. Adults tend to recover from lead ingestion better than children. If you think your children may be at risk, have them tested as soon as possible.

Iron deficiency can make lead easier to absorb in the body. Children with raised blood lead concentrations should have testing for iron deficiency.

Each person handles lead differently. What may be toxic to one adult may not be toxic to another. Thus, laboratory tests are just one part of the picture in lead poisoning cases. Careful monitoring with medical examinations are needed.