Lead poisoning is a serious health condition, especially for young children, that is caused by exposure to dangerous levels of lead. Lead is a heavy metal that can do harm to various parts of the body when too much enters the system. While lead poisoning used to be very common, public health efforts have greatly reduced exposure to lead in recent decades.
However, lead poisoning remains a risk and it’s important to understand potential sources of exposure. By learning about where lead is commonly found and how it can enter the body, people can take steps to prevent lead poisoning.
What are the most common sources of lead poisoning?
Here are some of the most frequent ways people are exposed to lead:
- Lead paint – This is the biggest source of lead exposure for children. Lead was used as an ingredient in household paints until it was banned for this use in 1978. However, lead paint is still present in older homes and when the paint starts to peel and chip, it creates lead dust and chips that are easily ingested or inhaled.
- Water – Lead pipes and lead solder used in plumbing systems can cause lead to leach into drinking water. Older homes and public water systems are more likely to have lead plumbing materials.
- Soil – Lead gasoline emissions and deteriorating exterior lead paint contribute lead to surrounding soil. Children who play outside can then ingest lead dust by getting dirty hands in their mouths.
- Toys and jewelry – Lead has historically been used in some cheap metallic toys and costume jewelry, especially those produced abroad and imported into the country. Lead solder is sometimes used in these products as well.
- Food and liquids – Lead can leach into canned foods and beverages stored in lead-soldered cans or lead-glazed pottery. Some folk remedies like Azarcon and Greta are also lead-based.
- Workplace exposure – Jobs that involve working with lead sources like smelting, manufacturing car batteries, refinishing furniture, construction, and auto repair can lead to workers bringing lead dust home on their clothes.
For children, lead paint dust in older housing is by far the most common cause of elevated lead levels. The older the home and the more deteriorated its paint, the bigger a risk it poses. Rental homes are more likely to contain lead paint hazards since they are less likely to have been recently renovated. Besides paint, children can also be exposed to lead brought home by parents who work with lead.
How does lead get into the body?
There are three main ways that lead typically enters the body:
- Ingestion – Swallowing lead dust is the most common route of exposure, especially for young kids. From lead paint, dust gets on surfaces around the home that children touch. When they put their hands and toys in their mouths, they ingest any lead dust. Soil contaminated with lead is also frequently ingested this way.
- Inhalation – Lead dust can be breathed in, especially during activities that generate a lot of dust like sanding or scraping during renovations. Adults who work with lead sources may inhale lead fumes or dust in occupational settings.
- Absorption – Lead can be absorbed directly into the bloodstream, like from lead-based folk remedies applied to the skin.
After lead enters the body, it spreads through the bloodstream and is absorbed into bones, organs, and tissues throughout the body. The body stores lead in bones where it accumulates over time with repeated exposures. Even after exposure stops, lead can leach back out of bones.
Who is most at risk for lead poisoning?
Some groups face higher risks of lead poisoning:
- Children under 6 – Young kids are more susceptible to the toxic effects of lead and more likely to ingest lead dust due to frequent hand-to-mouth behavior and higher absorption rates. Developing bodies absorb lead at a higher rate than adults.
- Pregnant women – Lead absorbed by the mother can be transferred to and harm the developing fetus. Lead exposure during pregnancy is linked to miscarriage, premature birth, low birth weight, and problems like learning disabilities later on.
- People living in older homes – Homes built before 1978 are very likely to contain lead paint, which poses a hazard when it peels or creates dust during renovations. Low-income families living in poorly-maintained rental homes are disproportionately exposed.
- Workers exposed to lead sources – Those working with lead products in industries like construction, auto repair, battery manufacturing, and painting/renovations are regularly exposed to higher lead levels.
Other high-risk groups include immigrants, refugees, and adults with certain hobbies like making bullets or fishing weights. People living near current or former lead smelting facilities or areas contaminated with high lead levels in soil may also face higher exposures.
| Age Group | Percentage with Elevated Lead Levels |
|---|---|
| Children under 6 years | 1.04% |
| Children 6-11 years | 0.55% |
| Children 12-19 years | 0.18% |
| Adults 20+ years | 0.12% |
This table shows the percentage of people with elevated blood lead levels in the U.S. by age group based on data from the National Health and Nutrition Examination Survey. Children under 6 have significantly higher rates of lead poisoning.
How much lead exposure is dangerous?
There is no known safe level of lead exposure. Even low levels in the blood can be harmful, especially for young children. The current reference level indicating an elevated blood lead level is 5 micrograms per deciliter (μg/dL).
Here are the health effects associated with different blood lead levels:
| Blood Lead Level | Potential Health Effects |
|---|---|
| Less than 5 μg/dL | Low levels can still cause subtle developmental and neurological issues in children. No effects are known in adults at this level. |
| 5-24 μg/dL | Developmental delays, learning difficulties, and behavioral problems in children. High blood pressure, kidney damage, and fertility issues in adults. |
| 25-44 μg/dL | Anemia, colic, muscle weakness, brain inflammation, seizures in children. Abdominal pain and reproductive harm in adults. |
| 45-69 μg/dL | Kidney disease, cardiovascular effects, impaired cognition in children and adults. Potentially fatal. |
| 70 μg/dL or higher | Brain swelling, coma, convulsions, death. Extremely dangerous. |
Because lead accumulates in the body, the duration of exposure also influences the level of risk and harm. Long-term exposures to even relatively low lead levels can lead to serious health problems over time.
What are the symptoms of lead poisoning?
Many symptoms of lead poisoning are subtle in low-level exposures. As the blood lead level increases, more severe symptoms appear. Common signs and symptoms include:
- Fatigue
- Abdominal pain
- Constipation
- Headache
- Irritability
- Loss of appetite
- Weight loss
- Learning difficulties
- Hearing loss
- Hyperactivity
- Developmental delay
- Seizures
- Coma
- Kidney failure
Symptoms often seem vague or mimic other health conditions, so lead poisoning can be overlooked. Blood lead testing is the only way to confirm if an elevated lead level is causing symptoms.
How is lead poisoning detected and treated?
A blood lead test is needed to detect lead poisoning or elevated lead levels. The blood test measures the amount of lead in the bloodstream. All children should undergo blood lead testing at ages 1 and 2, and again at ages 3-6 if at high risk due to living in an older home. Pregnant women and adults with lead exposure should also be tested.
Treatment involves removing the lead exposure and allowing time for the body to excrete the lead it has stored in tissues. For very high lead levels that cause severe symptoms, hospitalization may be required for IV medication to bind lead and help remove it from the body more quickly. Medications like chelation therapy help pull lead out from bones and tissues to be excreted through urine.
Nutrition supplementation with calcium, iron, and vitamin C is also used to decrease lead absorption in the body. Supportive medical care can help control symptoms until lead levels decline. Removing lead hazards from the person’s environment is a key step to prevent re-exposure.
Consistently monitoring blood lead levels is important during treatment to ensure they are declining at an appropriate pace. Long term effects like developmental delays may still persist after treatment.
How can lead poisoning be prevented?
The best way to prevent lead poisoning is to minimize or eliminate exposure to lead sources, especially in children:
- Test paint in pre-1978 homes and take steps to control lead hazards like chipping paint.
- Run water for 1-2 minutes before drinking to flush out lead from pipes.
- Clean regularly to control lead dust and make sure children wash hands frequently.
- Avoid using lead-glazed pottery for cooking or storing food and water.
- Don’t bring lead dust home from the workplace by changing clothes.
- Eat a nutritious diet high in calcium, iron, and vitamin C to decrease lead absorption.
Many cases could be prevented through screening and education programs to reduce lead hazards in homes. Government regulations banning or limiting the amount of lead in sources like paint, gasoline, food cans, and water pipes have also been instrumental in decreasing lead poisoning.
Conclusion
Lead poisoning remains one of the most common pediatric health problems and disproportionately impacts low-income communities of color. But public health efforts have made great strides in reducing lead exposures. While lead can come from many sources, the most dangerous and preventable threat is deteriorating lead paint in older homes.
By understanding where lead exposure comes from and how to prevent it, the risk of lead poisoning can be minimized. Blood lead testing, compliance with housing and health codes, and parental vigilance in reducing exposures are key protective factors, especially for vulnerable populations like children. With renewed awareness and proactive prevention measures, lead poisoning is an avoidable health condition.