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Lead poisoning is a condition, also known as plumbism or painter's colic, caused by increased blood serum lead levels. and evyn's going to fail his physics test
History
Lead was first mined in Turkey about 6500 BC. A 6000- to 8000-year-old necklace was found in the ancient city site of Anatolia. Lead's easy workability, low melting point and corrosion resistance were among its attractions.
Lead toxicity was first recognized as early as 2000 BC. Nikander of Colophon wrote of lead-induced anemia and colic in 250 BC. Gout, prevalent in affluent Rome, is thought to be the result of lead, or leaded, eating and drinking vessels. Lead was also used in makeup.
In 17th-century Germany, an Ulm physician noticed that monks who did not drink wine were healthy, while wine drinkers developed colic. The culprit was a white oxide of lead, litharge, added to sweeten the wine.
Today, most exposure in developed countries is the result of occupational hazards, leaded paint, and leaded gasoline (phased out in the US in the 1970s).
Symptoms and effects
The symptoms of lead poisoning include neurological problems, such as reduced IQ, nausea, abdominal pain, irritability, insomnia, excess lethargy or hyperactivity, headache and, in extreme cases, seizure and coma. There are also associated gastrointestinal problems, such as constipation, diarrhea, abdominal pain, vomiting, poor appetite, weight loss. Other associated affects are anemia, kidney problems, and reproductive problems. In humans, lead toxicity often causes the formation of bluish line along the gums, which is known as the "Burtons's line " A direct link between early lead exposure and extreme learning disability has been confirmed by multiple researchers and child advocacy groups.
Biological role
Lead has no known biological role in the body. The toxicity comes from its ability to mimic other biologically important metals, the most notable of which are calcium, iron and zinc. Lead is able to bind to and interact with the same proteins and molecules as these metals, but after displacement, those molecules function differently and fail to carry out the same reactions, such as in producing enzymes necessary for certain biological processes.
Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme Delta-aminolevulinic acid dehydratase, or ALAD. ALAD is a zinc-binding protein which is important in the biosynthesis of heme, the cofactor found in hemoglobin. Genetic mutations of ALAD cause the disease porphyria, a disease which was highlighted in the movie The Madness of King George.
Occurrence
Outside of occupational hazards, the majority of lead poisoning occurs in children under age twelve. The main sources of poisoning are ingestion of lead contaminated soil (this is less of a problem in countries that no longer have leaded gasoline) and lead based paints. This is particularly a problem in older houses where the sweet-tasting lead paint is likely to chip. In most American states, landlords and those selling such houses are required to inform the potential residents of the danger.
Measurement
One measure of lead in the body is the blood lead level (BLL), measured in micrograms of lead per deciliter of blood (μg/dL). Nearly everyone has a measurable BLL. The Centers for Disease Control and Prevention (CDC) states that a BLL of 10 μg/dL or above is a cause for concern. However, lead can impair development even at BLLs below 10 μg/dL.
The average person has less than 10 micrograms per deciliter, or 100 parts per billion, ppb, of lead in their blood serum. People who have been exposed to an unusual amount of lead will have lead serum levels higher than 200 ppb—most clinical symptoms of lead poisoning begin at around 100 ppb.
Treatment
Although the most important part of treating lead poisoning is decreasing exposure to lead, there are some forms of chelation therapy that can be used to reduce existing BLL levels:
Additionally, vitamin C (ascorbic acid), is also thought to act as a weak chelating agent (Llobet et al, 1990), and high serum levels of vitamin C have been associated with a decreased prevalence of elevated blood lead levels (Simon and Hudes, 1999).
Famous cases of lead poisoning
- Much of Rome's affluent class suffered from lead-induced gout
- The Devon colic was caused by the presence of lead in cider in 18th century Devon.
- Many historians have believed that Ludwig van Beethoven suffered from lead poisoning. This belief has been confirmed in 2005 by tests done at Argonne National Laboratory in the US on skull bone fragments, confirming earlier tests on hair samples.
- Lead shot for hunting has been banned in many countries because waterfowl often ingest spent shot, which kills some in a matter of weeks.
- Operation of a smelter in Trail, British Columbia contributed to higher than average blood lead levels in children living in Trail compared to nearby communities. A monitoring program, funded by the smelter and two level of government was established.
- In 1845, a crew of 128 searching for the Northwest Passage, under the leadership of John Franklin, are thought to have died from lead poisoning among other things. The canned food on board was sealed in tin cans with lead solder. The lead is thought to have leaked into the food and driven the men mad.
See also
External links
- Argonne Lab confirms Beethoven lead poisoning, Dec. 2005
- Case Studies in Environmental Medicine (CSEM): Lead Toxicity
- Helping Parents Prevent Lead Poisoning
- History of lead poisoning in the world
- National Pollutant Inventory - Lead and Lead Compounds Fact Sheet
- ToxFAQs™: Lead
References
- Llobet JM, Domingo JL, Paternain JL, Corbella J (1990). "Treatment of acute lead intoxication. A quantitative comparison of a number of chelating agents". Arch Environ Contam Toxicol. 19 (2): 185–9. PMID 2322019.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - Simon JA, Hudes ES (1999). "Relationship of ascorbic acid to blood lead levels". JAMA. 281 (24): 2289–93. PMID 10386552.