To screen for elevated concentrations of lead in your blood
If you may have been exposed to lead where you live or work; children especially should be tested as they may have inhaled dust or ingested substances that could contain lead (e.g., from paint chips or water from lead pipes found in older housing). It is also important that pregnant women who think they may have been exposed also get tested due to the risk of maternal to fetal transfer of lead through the placenta.
A blood sample taken from a vein in your arm
The test measures the concentration of lead within the blood. Lead is a metal that is known to be poisonous. In the past, lead was used in paints, petrol, and other household products, which can still be found, for example, in older housing. Some work activities and hobbies can still expose you to lead. While preventable, lead poisoning remains a public health problem in the UK that can cause irreversible damage to the health of children as well as adults.
If untreated, excess lead in the body can cause great damage, even if a person has no obvious symptoms or problems. Impaired learning and development among children is a major consequence of lead poisoning. The function of the kidneys may also be greatly reduced, and the ability of nerves to conduct messages quickly through the body is a major problem with lead toxicity. Lead can also harm the reproductive organs and cause miscarriages and birth defects when passed from mother to unborn child.
How is the sample collected for testing?
Most often, blood is taken from a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
The test is used to evaluate the concentration of lead in your blood to determine if you have been exposed to harmful levels.
Blood lead concentration is monitored in workers whose environment contains lead.In the UK the main sources of lead exposure are air-borne lead (from industrial sources and from the use of lead in petrol), 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).
When is it requested?
For screening: Blood tests may be requested 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. Adults who have hobbies that involve lead-based paints, ceramics, soldering etc should also be tested. For a list of hobbies that may expose you to potentially high levels of lead, go to lead poisoning.
The Health and Safety Executive (HSE) has developed rules for monitoring for lead in the workplace: In general, if a worker has a blood lead concentration of 2.4 µmol/L (500 µg/L) or higher then their employer is required by law to try to reduce exposure. If a concentration of 3 µmol/L (600 µg/L) or higher is found then the worker may have to be suspended from work.
For diagnosis: The test can help determine whether symptoms, including fatigue, stomach pains, 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. In children the symptoms of chronic lead poisoning are slightly different and they are more likely to present with, for example, developmental delay.
What does the test result mean?
The higher the test result, the more lead is in your system and the more potential danger there is to your health. However the amount of lead in the blood does not reflect the total amount of lead in the body. This will depend on how long a person has been exposed to elevated lead levels.
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 µmol/L (700 - 800 µg/L), a person is at the medical emergency level and should get immediate medical attention. Chelation will be considered in all patients with blood lead concentrations >2.4 umol/L (500 ug/L). 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/L) 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 blood lead concentrations should not exceed 0.5 µmol/L (100 µg/L). Any child who has an elevated blood lead concentration 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.
Is there anything else I should know?
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 be tested 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.
Apart from the sources of lead discussed above, recent cases of exposure have been from imported products such as cosmetics and household items and toys painted with lead paint.
What products in the UK still contain lead, besides paint and ceramics?
Products that still contain lead include batteries, solder, some pipes, ammunition, roofing, industrial paints, and X-ray shield materials.
How do people get exposed? Is touching these products enough to raise my blood level?
Just holding a lead object in your hands won’t poison you. Breathing in or swallowing lead may poison you, however. Some examples of lead poisoning situations would be:
- inhaling dust from a home renovation project on an old house
- drinking contaminated water, through old lead pipes
- swallowing lead shot (for a shotgun), a curtain weight, or a lead toy and not passing it through your system
- inhaling burning lead-painted wood or battery casings in home fireplaces
What occupations might result in a lead exposure?
Occupations that put people and their families at risk for lead exposure include:
- lead smelting plant
- steel welding
- bridge reconstruction
- firing range instructors and cleaners
- remodeling and refinishing
- foundry work
- scrap metal recycling
- car repair
- cable splicing
Are there ways to protect myself and my family from getting lead exposure if I work in a dangerous area?
Yes. If you are working in a potentially harmful environment with exposure to lead dust or mist:
- wash your hands before you eat, drink, or smoke
- eat, drink, and smoke in areas that are free from lead dust and fumes
- wear a properly fitted respirator with a HEPA filter. Shave your face to get the best fit
- keep your street clothes in a clean place, change into different clothes and shoes before you work with lead
- shower immediately after working with lead, before you go home
- launder your work clothes at the work place or separately from other family members’ clothes
How can I find out if my workplace is dangerous?