Lead exposure occurs through inhalation of lead dust or fumes or through ingestion of clothing, water or foods that contain the metal. Inhaled or digested lead is released into the blood and then distributed to different parts of the body. Most of the lead builds up and is stored in the bones, which then release it back into the blood, meaning organs are re-exposed long after the initial exposure.

In the US, the metal used to be commonly found in lead-based house paints and gasoline . Although the use of lead in these materials is no longer allowed in the US, lead is still a problem because it is present in dust, dirt and old house paint.

Lead poisoning can be difficult to detect and even apparently healthy people can have a high amounts of lead in their body. The signs and symptoms of lead poisoning are not apparent until the lead has accumulated to a dangerous level.

Lead Poisoning in Children

There are many different signs and symptoms of lead poisoning as lead can affect all organs and bodily functions to some degree. Signs and symptoms vary depending on the level of exposure. Children may develop serious symptoms that require urgent medical attention if exposed to a single high dose of lead, but it is more common for lead to build up gradually in a child’s body over time, which happens when children are repeatedly exposed to small amounts of lead. In these cases, children can have lead poisoning without displaying any signs or symptoms, with many children appearing and acting healthy. Sometimes, vague symptoms may develop that get mistaken for other illnesses such as flu or a stomach upset, which means lead poisoning is often not recognized and diagnosed. Lead poisoning is detected using a simple blood test to check the level of lead in the blood.

Children are much more prone to the harmful effects of lead than adults are because it can affect the development of their nervous system and cause permanent brain damage. The younger the child, the more damaging the lead poisoning can be and exposure to very high levels can lead to coma, seizures and death.

Children with lead poisoning may develop the following signs and symptoms:

• Delayed development
• Learning difficulties
• Irritability
• Poor attention span
• Loss of energy
• Appetite loss
• Weight loss
• Abdominal aches and pains
• Constipation
• Sickness
• Loss of hearing
• Hyperactivity
• Difficulty sleeping

Newborns exposed to lead before birth may experience the following:

• Delayed growth
• Learning difficulties

Lead Poisoning in Adults

Although children are at the greatest risk of the damaging effects of lead poisoning, adults can also be affected. Symptoms that may develop in adults include the following.

Neurological effects

• Pain or tingling in the extremities
• Fatigue
• Irritability
• Mood disorder
• Impaired concentration
• Decline in mental function
• Loss of hearing
• Headache
• Seizures
• Encephalopathy
• Loss of memory
• Muscle pain
• Muscle coordination problems

Gastrointestinal effects

• Constipation
• Indigestion
• Nausea
• Abdominal aches and pain

Reproductive effects

• Pregnant women may have a miscarriage, premature birth or stillbirth
• Men may suffer from impotency
• Men may have a reduced sperm count, reduced sperm motility and abnormal sperm

Effects on heme synthesis

• Erythrocyte protoporphyrin elevation
• Anemia

Renal effects

• Kidney problems
• High blood pressure