The Burton line is a very thin, bluish-purple line that is found in a person's gums as a clinical indicator of lead poisoning. It sits at the junction of the teeth and gums, and it usually covers the distance of two or more teeth. The line is caused by lead sulfide, which is created by the extra lead in the body reacting with sulfur ions that are released by bacteria in the mouth. Although the line is a very good indicator of lead poisoning, it does not appear in every case, making it a useful diagnostic tool but not a definitive one. The only sure way for lead poisoning to be diagnosed is through a blood test.
The line is named for the English Physician Henry Burton who first discovered the link between lead poisoning and gum discoloration in the 1800s. Dr. Burton did a lot of work with lead poisoning and was one of the first to do research into its harms, specific symptoms, and treatments.
Understanding Lead Poisoning Generally
Lead is a natural mineral in the Earth's crust. It has a number of important uses, but it can also be very harmful to humans if ingested or inhaled. Mining, burning fossil fuels, and manufacturing have made exposure to lead more prevalent. Lead paint and leaded gasoline — two major lead-based products — have been outlawed in some countries due to the risks of poisoning. Lead still is used, however, in products such as batteries, solder, piping, pottery and some roofing materials. In some countries, home remedies containing lead are also used for everyday problems such as upset stomach, nausea, colic, indigestion, and teething babies.
Children who are less than 6 years old are much more susceptible to lead poisoning than adults are. Young children's most common exposure to lead is through eating pieces of lead-based paint or through contaminated dust and soil. Some symptoms of lead poisoning in children include developmental problems, irritability, weight loss, abdominal pain, and vomiting. Adults typically are exposed to lead through batteries, home renovations, hobbies, or working in auto repair shops. Symptoms of lead poisoning in adults include increased blood pressure, decreased mental function, numb or tingling extremities, low sperm count in men and miscarriage or premature birth in women.
How the Line is Used
Physicians and other medical care providers often look for the Burton line during routine physical exams, and it is usually checked for during dental cleanings, too. It’s also one of the first things care providers look for in suspected lead poisoning cases. Healthy people don’t normally have any lines or markings on their gums, and in this respect a bluish tint is usually a sign that something isn’t quite right. Researchers have found a strong connection between the appearance of this line and high levels of lead in the blood. Just the same, treatment isn’t usually started until the diagnosis is confirmed, usually with a blood sample.
The only way for lead poisoning to be accurately diagnosed is with a blood test. Lead in the blood is usually measured in micrograms per deciliter, and a level that is at or above 10 micrograms per deciliter is considered unsafe. In some places, blood tests are required for all infants regardless of their perceived risk and regardless of whether their gums betray the Burton line.
The treatment for lead poisoning is often as simple as removing or avoiding the source of lead. This can mean repainting an old piece, dusting more frequently, or finding a new hobby. People who live in homes that have lead-based paint on interior walls often have a much harder path, though. Lead paints were common in the United States and many other places through the 1950s, and are still used in some countries. Simply repainting isn’t usually enough to reduce the risk of fumes or contaminated paint chips. Often, walls must be completely stripped and resurfaced, usually at great cost.
For blood levels more than 45 micrograms per deciliter, a treatment called chelation therapy is used. In chelation therapy, a medication is given either orally or intravenously, and it binds to the lead and causes it to be excreted through the urine. With higher blood levels, even though the lead might be removed from the body, the damage that has been done might not be reversible. Once the lead has been removed from a person’s blood the Burton line will disappear, though this can take a few days.