Lead poisoning refers to a build-up of lead in the body. These levels can take months or years to reach a dangerous level and, at worst, can be fatal.
Having first been mined in Anatolia at around 6500 BC, lead poisoning is one of the oldest work and environment hazards known to man.
Lead's negative health consequences have been known since at least the 1st century AD when the ancient Greek physician Dioscorides noted that lead makes the mind "give way." However, it was not until the end of the 20th century that scientists discovered how even minute quantities of lead can cause serious harm.
In this article, we will discuss the symptoms, diagnosis and treatment of lead poisoning. We will also look at how lead works as a poison as well as ways to minimize the risks of lead poisoning in the home.
Contents of this article:
Fast facts on lead poisoning
Here are some key points about lead poisoning. More detail and supporting information is in the main article.
- Lead is a naturally occurring heavy metal
- All biological systems in the human body can be damaged by lead poisoning
- Children and the unborn child are particularly susceptible to lead poisoning
- An estimated 24 million American homes contain unsafe quantities of lead paint and/or dust
- The production of lead-based paint was banned in America in 1978
- An estimated 3 million workers in the US are at risk of toxic lead exposure
- Lead poisoning symptoms can include nausea, dizziness, reduced IQ and a strange taste in the mouth
- Some traditional medicines contain lead
- Lead prevents the normal functioning of vital enzymes
- Lead can reduce the total volume of brain tissue.
What is lead poisoning
Lead is a naturally occurring heavy metal.
Lead is a heavy metal and a particularly strong poison. It can accumulate in the body if it enters the mouth or is inhaled. Lead can also enter through splits in the skin or via mucous membranes.
Once inside the body, lead can damage all of the systems within it, including the heart, bones, kidneys, teeth, intestines, reproductive organs and the nervous and immune systems
Children, especially those under the age of 6, are particularly sensitive to lead poisoning. It can irreversibly damage mental and physical development.1
The most common sources of lead poisoning are from lead-based paint in older buildings, lead-based dust and contaminated water, air or soil.
Children are more at risk from lead poisoning for a number of reasons:
- They are more likely to pick up lead contamination from the soil and to then consume it
- They are also closer to ground level more frequently and, therefore, more at risk of breathing in dust from the floor.
Young children absorb lead in their stomach up to 10 times more readily than adults and, because their bodies are still developing, the risks are further increased.2,3
The Centers for Disease Control and Prevention (CDC) estimate that at least 24 million American homes harbor deteriorated lead-based paintwork and lead-contaminated dust. Four million of these homes contain young children.4
Children who live in less developed countries are at the highest risk of lead poisoning because legal controls on the usage of lead are not as strict as in the US.
Adults who work in auto repair shops or do home improvements can also be at risk of lead poisoning, especially if their home was built before lead-based paint was banned in 1978. An estimated 3 million workers in the US are at risk of toxic lead exposure.5
Symptoms of lead poisoning
Worryingly, the symptoms of lead poisoning do not become apparent until a dangerous amount of lead is already present in the body. Occasionally, lead poisoning can occur from a single high dose, but more often it is a gradual build-up.
Symptoms of lead poisoning vary across age groups:
Lead poisoning in children
- Slowed body growth
- Reduced IQ
- Loss of skills
- Loss of appetite and weight loss
- Abdominal pain
- General fatigue
- Hearing loss and reduction in other senses
Lead poisoning in adults
Lead poisoning can cause hallucinations.
- Abdominal pain - generally the first sign if a high dose of lead is ingested
- Raised blood pressure
- Joint and muscle pain
- Tingling, pain, numbness in the extremities
- Memory loss and decline in mental functions
- Unusual taste in the mouth (often described as metallic)
- Difficulty sleeping
- Mood disorders
- Reduction in sperm volume and quality
- Miscarriage or premature birth.
On the next page, we look at the causes of lead poisoning and how it produces illness.