Learn About Lead Poisoning

Frequently Asked Questions About Lead Poisoning

What is lead?

Lead is a potent neurotoxin, of which there is no known safe level of exposure according to the World Health Organization. Blood lead levels at or above 5 micrograms per deciliter (µg/dL) is the level at which the United States Centers for Disease Control and Prevention have stated requires intervention, and a level at which the World Health Organization says may be associated with decreased intelligence in children, behavioral problems and learning difficulties.

How is lead poisoning defined?

Lead poisoning is the harm to body systems from lead intoxication. Since lead poisoning can, and often does occur without clinically obvious symptoms, the concentration of lead in children’s blood (blood lead level) is used as an indicator of the severity of poisoning. 

Over the last century, the blood lead level at which lead is known to exert toxicity has declined steadily. Today, the World Health Organization recognizes that “there is no ‘safe’ concentration of lead in blood” and “recent research indicates that lead is associated with neurobehavioral damage at blood levels of 5 µg/dL and even lower” and finally “it is now quite clear that there are adverse neurodevelopmental effects at the lowest blood lead concentrations yet studied.” 

It is understood that lead pollution was largely eliminated due to the removal of lead in gasoline in most countries, why are so many children still affected?

Lead is a heavy metal that can be easily molded and shaped. Humans have used it for centuries in a variety of products. The sources of lead exposure to children include, but not limited to, lead in water due to the use of leaded pipes; lead from an active industry, such as mining and thus polluting soil; lead-based paint and pigments; leaded gasoline – which has declined considerably in recent decades, but has historically been a major source; lead solder in food cans; and lead in spices, cosmetics, toys as well as other consumer products.

One of the major contributors of lead pollution in recent years has been caused by lead released during informal lead acid battery recycling, incineration of lead-containing waste, e-waste recycling, and smelting, often conducted in informal, unlicensed, and frequently illegal backyard operations within a few meters of homes and schools. 

Since 2000, the number of new vehicles in low- and middle-income countries has more than tripled, with much of that growth coming since 2005. Demand for lead-acid batteries has grown exponentially with the increase in traditional vehicles, electric cars and scooters and technologies that rely on battery storage.  

Why are so many children affected by lead poisoning?

The informal recycling of lead-acid batteries is a leading contributor to lead poisoning in children as they inhale the dust and fumes in neighborhoods and schools close to poorly monitored and often illegal factories. 

Up to half of used lead-acid batteries end up in the informal economy where unregulated and often illegal operations break open cases, spilling acid and lead dust into the soil, and smelt lead in open-air furnaces that emit toxic fumes.

Other sources of childhood lead exposure include lead in water from the use of leaded pipes; lead from active industry, such as mining and battery recycling; lead-based paint and pigments; leaded gasoline, which has declined considerably in recent decades, but was a major historical source; lead solder in food cans; and lead in spices, cosmetics, ayurvedic medicines, toys and other consumer products. Parents whose occupations involve working with lead often bring contaminated dust home on their clothes, hair, hands and shoes, thus inadvertently exposing their children to the toxic element.

Why are children more affected by lead pollution than adults?

Children are most vulnerable to the toxic effects of lead, which can cause irreversible and lasting damage to the developing brain and nervous system, as well as risk their overall health.

Children, particularly young children are most affected by lead poisoning and its lifelong implications for four main reasons: 

  • Babies and young children absorb about 4-5 times more of the lead that enters their bodies than adults do. Lead absorption in their gastrointestinal tract is higher. Children, with their higher respiration rates, also breath in a greater volume of air per unit of body weight than do adults – and consequently more lead particles per unit of body weight.
  • The likelihood of ingesting soils and dust that is contaminated with lead is higher due to the way children play closer to the ground, often outside and in/on/with dirt that could potentially be contaminated.  Higher propensity to engage in hand-to-mouth behavior and pica also presents greater risks. 
  • The blood-brain barrier is still developing in children, especially at young ages. For these reasons, the neurological effects often occur at higher levels.
  • Deprivations that occur during the critical window of early childhood can have life-long implications, affecting educational outcomes, future wages and children’s social and economic potential in life. This cannot only exacerbate poverty but also, because exposure to lead often affects the poorest the most, inequality.

What are the consequences of lead poisoning in children?

Lead is a potent neurotoxin that causes irreparable harm to children’s brains. It is particularly destructive to babies and children under the age of five whose brains are damaged before they’ve had the opportunity to fully develop, leading to lifelong neurological, cognitive and physical impairment. 

Once ingested, lead is absorbed through the digestive tract and distributed via the bloodstream throughout the body, most significantly affecting the kidneys, liver, heart and central nervous system, as well as the hematopoietic, endocrine, and reproductive systems. Like calcium, which it mimics, lead is stored in teeth and bones where it builds up over time to be released into the bloodstream during pregnancy or when a bone is broken. Recent exposure to lead can be measured in blood samples, while cumulative exposure can be measured in teeth or bones.

Childhood lead exposure is linked with mental health and behavioral problems, and an increase of crime and violence. Older children exposed suffer severe consequences including increased risk of kidney damage and cardiovascular diseases in later life.

Despite its severity, lead poisoning in children causes few early symptoms, meaning it silently wreaks havoc on children’s health and development until it’s too late. At the highest levels of exposure, its youngest victims do not survive. For survivors, their life chances are altered forever.

Childhood lead exposure is estimated to cost lower- and middle-income countries almost USD $1 trillion due to the lost economic potential of these children over their lifetime.

What are the signs of lead poisoning?

A challenge with childhood lead poisoning is that many of the symptoms are not visible or even materialize until later – and children can remain asymptomatic for a prolonged period of time, especially with lower levels of exposure to lead. 

At higher, more acute lead poisoning levels, children may complain of a variety of non-specific symptoms, such as headaches, abdominal pain, dullness, loss of memory, poor attention, loss of appetite or constipation. 

The impacts of lead poisoning on neurological processes and the central nervous system may result in indications of clumsiness, agitation, or decreased activity and drowsiness, which can proceed to vomiting, stupor and convulsions in more severe cases. Any symptoms due to lead toxicity must be treated as an emergency.

Is there any treatment for lead poisoning?

There is no cure for lead poisoning. However, treatment for acute and severe lead poisoning can include chelation therapy to remove some of the lead from the blood. Studies show that a good diet, high in iron and calcium, can also reduce the effects of high blood lead levels. 

However, most responses involve preventing further exposure, and removing sources of lead in the child’s environment. Improved educational and early childhood development services can also mitigate some of the negative cognitive effects associated with exposure. Once lead has been in the body for a prolonged period of time, however, it is very difficult to remove as it is frequently deposited in bones – and much of the neurodevelopmental damage has already been done.

What is the economic impact of lead poisoning among child populations?

Lead is a potent neurotoxin that causes irreparable harm to children’s brains. It is particularly destructive to babies and children under the age of five whose brains are damaged before they’ve had the opportunity to fully develop, leading to lifelong neurological, cognitive and physical impairment. 

Childhood lead exposure is linked with mental health and behavioral problems, and an increase of crime and violence. Older children exposed suffer severe consequences including increased risk of kidney damage and cardiovascular diseases in later life.

Despite its severity, lead poisoning in children causes few early symptoms, meaning it silently wreaks havoc on children’s health and development until it’s too late. At the highest levels of exposure, its youngest victims do not survive. For survivors, their life chances are altered forever.

Childhood lead exposure is estimated to cost lower- and middle-income countries almost USD $1 trillion due to the lost economic potential of these children over their lifetime.

Why is lead’s use so prevalent when we know how dangerous it is?

Lead is a heavy metal that can be easily molded and shaped. Humans have used it for centuries in a variety of products.

Lead is also highly recyclable and can be recycled safely and cleanly through practices consistent with circular economy and closed-loop supply chain principles, as is the case in high-income countries with environmental regulations and monitoring. However, many, if not most, lower- and middle-income countries lack sufficient formal recycling infrastructure and capacity to handle the quantity of used lead-acid batteries flooding their markets. As a result, as much as half of the used lead-acid batteries end up in the informal economy where unregulated and often illegal operations break open cases, spilling acid and lead dust into the soil, and smelt lead in open-air furnaces that belch toxic fumes across surrounding neighborhoods.  

This process is linked to the variety of other sources of children’s potential exposure to lead. Lead from informal secondary recycling makes its way into products beyond vehicle batteries. In Mexico, the lead-based pottery glazes on cookware and serving dishes remains a significant source of lead exposure for children and adults. Spice processors in several countries, including Georgia and Bangladesh, add lead chromate to spices, such as turmeric, to enhance color and weight, which contributes significantly to elevated lead blood levels among children and adults.