Lead Urine Test

Your doctor may order this test if he/she suspects that you have been exposed to lead. 

Symptoms of lead toxicity involve:

• Fatigue
• Abdominal pain
• Loss of appetite
• Weight loss
• Headache
• Impaired memory 
• Disorientation
• Difficulty in concentration and behavioural problems 
• Fits and coma – in case of high exposure

The test is performed as a substitute to the lead blood test when the latter is not feasible due to repeated testing as in case of workplace exposure, fear of needles or difficulty in locating a vein.

A lead urine test is also performed to monitor the treatment for lead poisoning. Lead poisoning is treated with chelating agents when the lead blood levels exceed 40 µg/dL (micrograms per deciliter) in adults and 25 µg/dL in children. These substances bind to lead and remove it in the urine. This results in higher levels of lead in the urine and a corresponding drop in blood lead levels.

Stop eating seafood 48 hours before the test. If you have undergone a procedure involving iodine- or gadolinium-containing contrast mediums, wait for at least 96 hours before you go for the test as the mediums could affect the test results.

This is a simple test that requires a random urine sample - that is, the sample can be collected at any time of the day. You will be provided with a sterile container to collect the sample. A doctor or nurse will give you the following instructions before the test:

• First, wash your hands thoroughly with water (avoid soaps) and air-dry them to prevent contamination of the urine cup
• Next, urinate into the sterile cup provided by the laboratory 
• Your urine sample will be frozen until it is analysed 

There are no side effects or risks involved with the test. A clean-catch midstream sample should be collected. Take care to avoid contamination of the sample with blood, hair or faecal matter. Do not use a metal bedpan for sample collection.

Normal results:

A normal result may be reported as negative. It means that there is no lead in the given urine sample. Normal results are seen when treatment for lead poisoning is complete and lead concentration in the blood and urine is less than 5 µg/dL. Results may also be negative if there has only been minimal lead exposure (lead blood concentration < 10 µg/dL). Your doctor will precisely explain what the results mean for you.

Abnormal results:

An abnormal result may be reported as positive. It indicates the presence of lead in the urine. Higher than normal levels of lead in the urine may be due to constant lead exposure. A rise in lead levels in urine is also seen during treatment for lead poisoning but is considered normal. This surge in urine lead levels occurs because the chelating agent clears the lead in the body through the urine.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.