An Overview of the Urine Test for Lead
Where Is Lead Found?
Lead is a metal that is used in manufacturing. In the past it was used to produce paint and applied as a coating on kitchen utensils. Lead was also used to solder pipes together in some old homes. When lead is ingested, lead poisoning can occur, and it can affect vital organs within the human body.
Systems Affected By Lead
An increase in the amount of lead within the body can produce a variety of symptoms. The main organs that are affected are brain, kidneys, testes and ovaries. Other organs can have lead toxicity if the levels are high enough.
Lead toxicity affects the reproductive organs and this metallic lead can be deposited within the testes and ovaries. This can result in having a negative affect on a couple’s ability to have a child.
Lead toxicity affects the gastrointestinal system to produce nausea, vomiting, lack of appetite, constipation, weight loss, lack of energy and abdominal pain. This toxicity can affect the circulatory system to produce anemia and abnormal red blood cells.
Lead toxicity within the kidneys is also quite serious. Adults will have high uric acid levels and the person might be mistaken for having gout. Children will have a decrease in the amount of urine they produce and show signs of dehydration.
When lead gets into the central and peripheral nervous system it can affect the nerves to cause foot and wrist drop, muscle weakness, mental and behavioral problems, headaches, irritability, disturbed sleep, hearing loss, seizures, hallucinations, coma and death.
Who Is Mainly Affected?
Children are usually affected because of exposure to lead in home paints or from pipes. They are quite susceptible to lead toxicity as their bodies are still developing. Adults can be affected by lead dust but also through their occupation.
Some adults are exposed to lead directly or indirectly in their workplace, if they work in the manufacturing or production industry in construction, smelting or scrap meta, for example. In some instances, lead has been detected in foods and medications produced internationally and imported into the country.
Urine Testing
A person’s lead level will naturally increase slowly over time. The main test for lead toxicity is a blood test to detect a blood level of more than 10 mcg/dL. A person is monitored at levels above this and the source of toxicity is discovered with immediate removal necessary.
If it is not possible to do a blood test or a less invasive procedure is needed, lead can be detected in urine. The specific test for the presence of lead in urine is detection of decreased delta-Aminolevulinic acid dehydratase (ALAD) levels. This enzyme is used in hemoglobin and red blood cell production. The other general tests for levels of lead in urine is a 24-hour sample of urine that is collected in a large container. The physician will order regular kidney function urine test.
Therefore with the 24-hour urine sample, the laboratory will test the levels of uric acid, the specific gravity of urine and kidney function creatinine levels.
Lead Toxicity Urine Results
In the specific test result for ALAD dehydratase levels, this enzyme is inhibited in the presence of lead and will show an increased level of Aminolevulinic acid in the urine.
In general test results, adults more than children will show a lower level of uric acid in urine. This could mean that the kidneys are damaged and unable to remove uric acid from the body. The uric acid is deposited in areas such as the joints producing symptoms of clinical gout. The urine’s specific gravity is increased, especially in children. This could mean the body is in a state of dehydration. It is might be difficult to collect urine in a child because of decreased urine output. Keep in mind that in many instances, a blood test is preferred over a urine test for lead.
References
Medscape.com, Lead Toxicity In Emergency Medicine
