The Effects of Lead Poisoning in Children, Research Paper Example

Exposure to lead is an environmental hazard to children, especially young children. Lead is a highly toxic metal that has been used in a number of products for centuries. Most products containing lead can be found in most average households. It is a naturally occurring metal that is found within the crust of the Earth and is considered a toxin that can lead to serious health concerns for children. Lead has commonly been used in paints, pipes, gasoline, batteries, cosmetics and can also be found in soil and water. While small amounts of lead exposure have been said to be non-toxic, heavier concentrations or exposure can lead to neurological disorders, stunted mental development, problem behavior as well as a number of long term medical complications. In recent studies, even small levels of lead consumption have been noted at dangers for developing children. Increased levels of lead exposure are detrimental for adults as well; however it creates a complex concern for children because of increased absorption rates, and a decreased neurological development (Bellinger, 2008).

Regulations & Laws

While the dangers of lead have been addressed throughout history, it was around the 1970’s when the true detriment of lead poisoning became prevalent. In a 1970 statement the United States Surgeon General issued statement about the harms of lead poisoning to the general population, but especially young children (U.S. Department of Health, Education and Welfare, 1970). A year later the Lead Paint Poisoning Prevention Act was passed to provide money for screening programs and treatment. With the additional screening process it became clear that there was a higher prevalence and problem with lead exposure than previously thought. This was especially true for children living in high risk areas, such as inner city housing.

The Lead Contamination Control Act of 1988 was founded to implement policies and guidelines to assist in the prevention of lead poisoning in children. The Center for Disease Control and Prevention is challenged with implementing policies and programs to assist in educating the public, providing funding for screening, research and treatment for medical care. The Federal Government has implemented programs and regulations to assist in protecting children from exposure, as well as providing preventative measures. With one of the largest contaminations being lead based paints in older homes, the HUD Lead Hazard Control Grant Program has been enacted. This program provides resources at the state level to assist in the control and cleanup of low income housing. This is primarily meant to address the federal regulations that require landlords or owners of the property to identify and remedy the lead hazard before allowing tenants to live in the property. This allows the state government to become involved in the prevention and clean-up of lead that could lead to possible exposure or contamination for children.

Background Information

Exposure to lead can occur through inhalation, ingestion and be absorbed through the skin. Once ingested into the body it acts as a poison and is distributed in the bloodstream throughout the body. According to Bellinger, the damage that occurs within the red blood cells prevents oxygen from reaching vital organs (2008). The ability for the red blood cells to replicate is greatly reduced, which depletes nutrients to the body’s vital organs. The decreased nutrients and ability to absorb important nutrients interferes with bones, teeth, blood vessels and even nerve functions. Lead is absorbed into the human body through various methods. Absorption through the skin is possible, however not the most common method of entry. Tetraethyl lead is

one of the only types of lead that can be absorbed through the skin and is commonly found in gasoline (Bellinger, 2008). Lead is generally taken into the body through airborne exposure in adults and hand to mouth transfer in children. Oral ingestion is the most common route for children and directly affects their GI tract because of the heightened absorption rate. The explanation for faster absorption for children can be explained through their eating habits and their decreased blood serum levels which allow lead to absorb much quicker, through the lowered levels of iron, calcium and zinc (Erickson & Thompson, 2009).

Children playing in contaminated soil or ingesting lead contaminates such as paint chips are the primary method of exposure. Slow exposure can also occur through breathing workplace or household dust that is contaminated with lead, which increases the toxin within the body over time. Because the body is unable to use lead in a productive manner it simply remains stored within the bones, tissues and organs. According to the Department of Ecology in Washington, adults can excrete approximately 99% of absorbed lead; however children are only able to excrete approximately 32% (2005). The remaining lead that is not excreted is primarily stored in the bones and teeth. The remainder is referred to as the “body burden” and is based on the difference between lead absorption and excretion. Lower levels of lead are most commonly stored in organs such as kidneys, liver and pancreas, whereas higher levels can remain in the bones for many years after exposure. While some of the lead can be excreted through the kidneys, the half-life is approximately twenty-five years, leaving much time for extended health concerns.

Literature Review

Much research has been conducted on the effects of lead exposure and its health effects on children. Research conducted by the World Health Organization and Center for Disease Control and Prevention suggest that children whose lifetime peak blood levels were low (<10dL) had an association between their blood lead level and intellectual impairment, which suggests that there is no safety margin for exposure to lead (Koller, 2004). The 2004 study took into account factors such as socio-economic status, home environment and genetic factors as well as demographics of their parents in order to determine intervening variables. The impact on the child’s IQ level is typically measured by the Stanford – Binet Intelligence Scale, which is a standardized test that measures cognitive abilities of children beginning at two years of age through adulthood. Testing can identify learning disabilities, delays and mental retardation. Between the years of 1994 and 1995 a longitudinal study was conducted by Canfield and Colleagues of 240 children living in Rochester, New York. Researchers measured the blood levels of the children at six month interval’s ranging from 6 months to 60 months of age. Between the ages of 3 and 5 the Stanford – Binet was administered to determine the IQ level of the children enrolled in the study. Canfield and his Colleagues found that there was a significant relationship between the level of lead in the blood and the child’s IQ level. The results suggest that for every microgram per deciliter that there is a 0.46 point decrease in IQ (2003). Just like the work of Koller, these findings suggest that there is no safety margin for exposure of lead to young children and proves the detriment to their cognitive abilities.

Bellinger, Stiles and Needleman, examined white working class families with small children in order to determine if there was a cultural difference (1992). The reason for the study

was due to the previously thought higher prevalence in poor or lower socio-economic status families. The study found that the children having a low to moderate blood lead level, also suffered from cognitive deficits, poor academic outcome and behavioral issues (Bellinger , Stiles & Needleman, 1992). This suggested that all children were at risk for the detrimental effects of lead exposure, not only those living in lower income areas. One of the primary deficits of children studied was the lowered reading abilities of the children. Early literacy and the ability to read are highly related to the educational success of a child. The study found that there was a significant relation between lead blood levels and children’s reading ability.

Thesis Statement

The prevalence of a heavy weight metal such as lead concentrated in high quantities or prolonged exposure can cause significant irreversible illnesses in children and adolescents. Lead can be found in a number of children’s products, as well as environmental substances. The theoretical implications of increased lead blood levels have been linked to behavioral, learning, social and medical disorders, suggesting that there is no safe level of exposure.

Lead Based Paint

Prior to 1960 most homes contained paint that was lead based, which exposed many children to potential endangerments. One of the most common methods of lead poisoning in children is through the consumption of paint chips. Young children have been known to eat paint chips, chew on wood window frames or other structures containing lead based paint. Along with oral consumption, children can be exposed through dust from the paint, peeled or chipped areas that are stepped on and even breathing airborne lead dust from simply opening a window with lead based paint. Lead dust can commonly be found on walls, floors and furniture, which present a health hazard to small children, especially.

The first established link between cognitive health concerns and lead paint was in 1904. Prior to this time there was much disbelief about the negative effects of lead. It was discovered that there was a negative correlation between lead based paint and children in Australia, when researchers found that lead based paint had caused lead poisoning in high numbers of children (Needleman, 2004). A short time later the United States the first case of pediatric lead poisoning was noted. In order to reduce the amount of exposure new formulas have been enacted along with the introduction of latex paints. In the United States, today, paint cannot have a higher concentration of lead than .06% (Stroop et al., 2002).

High Lead Content In Food Products

Lead is a naturally occurring metal and has been used extensively over the years. Plumbing is one of the leading manners of distribution into a home’s water supply. Pipes before 1986 were primarily lead which allowed the toxin to enter the water supply. The Safe Drinking Water Act was created requiring only lead free pipes or solder for human consumption. Prior to the Act, lead pipes and solder allowed lead to readily dissolve into drinking water, therefore contaminating the water. In order to address the amount of lead found in tap water the Environmental Protection Agency (EPA), established criteria for the amount of lead in the drinking water supply. In 1991, the level was formulated to be safe at 15 micrograms per liter or 15 parts per billion (EPA). Restrictions were also placed on the water sources to ensure that levels do not exceed the recommended safety range and if so required them to take action.

Another source of lead toxins in food supply is the indirect consumption of animal meat, fruits and vegetables. In areas with high levels of lead concentration, animals and plants can also

have higher levels of lead. Once consumed by humans that lead can be transferred, which builds over time within the body. Other sources of exposure are found in some dietary supplements, lead-soldered cans and even certain food wrappers (Goyer, 1996). According to Goyer, the Food and Drug Administration monitors and has issued standards regarding the amount of lead that can be found in any type of food product, primarily those marketed or commonly consumed by children (1996). While many actions have been taken to reduce the amount of lead exposure an ongoing concern is items imported from other countries that do not follow the United States FDA requirements or suggestions. A number of other countries are still using food products or containers that are high in lead content, which in some cases are being sold in the United States, which causes a heightened need for oversight.

Lead based cooking utensils can also cause lead to enter the food supply. The materials used in cookware can leach into the food during the cooking process. A recent report notates that porcelain cookware imported from Mexico and China contained high levels of lead content. Dr. Gilmore of the Center for Disease Control Advisory Committee on childhood lead poisoning prevention, reported that 25.3% of items tested in Philadelphia’s Chinatown contained high levels of lead (Thomas Jefferson University, 2011). These ceramic pots, pans and cooking utensils were for sale and to unsuspecting consumers who thought they were safe because they were purchased in the United States. This creates a concern because these products are being sold and marketed to unsuspecting parents with children.

Toys with a High Lead Content

In most nurseries and children’s rooms there are many types of toys. Actions figures, stuffed animals, replica cars and a host of other items. Most children not only engage in

imaginative play, but also frequently place their toys in their mouths. In 2007 it came to the attention of the United States that the toy manufacturer Elite Operations was selling toys that had a thick coat of glossy paint, which loaded with 5,000 ppm of lead (Schmidt, 2008). Elite Operations is a toy manufacturer that is based in Hong Kong and sold hundreds of thousands of products to toys stores, such as Toys R Us. Mass recall was initiated however not before children had been exposed to the high content of lead in these toys. Since 2007 there have been 42 recalls in the United States that have led to approximately 6 million toys being taken off the shelf because of high levels of lead content (Schmidt, 2008). The problem remains a concern because of large toy manufacturers that outsource work to overseas companies. Monitoring the imports and ensuring that all toys meet the United States requirement is a difficult task, because of the amount of imports that take place on a yearly basis. The Consumer Product Safety Commission has implemented a paint standard of 600 ppm in response to the 2007 levels that contained paint with 1000 to 2000 ppm (Schmidt, 2008). While the standards are imposed it is toy manufacturing giants such as Mattel to ensure that their products are safe regardless of where they are made or imported from.

Health Impacts Of Lead Poisoning

After ingestion, regardless of the manner, lead is bound to red blood cells, which is then distributed to soft tissue and organs. It has been compared to the movement and storage of beneficial chemicals such as calcium. It is moved to organs such as the kidneys, liver, bone marrow and the gray matter of the brain (Erickson & Thompson, 2009). According to John Hopkins Medicine the renal system is negatively affected by lead levels of 2.9 or more (Navas-Acien et al., 2009). Researchers at Hopkins found that a level of 2.9 or higher decreases the kidney function in children that are free of other medical illnesses or disease. The rate and manner by which the kidneys filter the blood was slower in these children, which can create chronic kidney disease and result in further problems into adulthood. The measure of kidney function is measured by the rate that creatinine is filtered from the blood (Navas-Acien et al., 2009). Because the kidneys are responsible for filtering wastes from the body, such as creatinine, the slower rate allows toxins to remain in the body thereby causing additional kidney damage. The kidneys control the level of water within the body and when not functioning properly can lead to dehydration, because of the inability to return needed nutrients back into the body such as sodium and potassium.

The Hematological System

Lead retards the synthesis of heme, which is the part of the blood that carries oxygen throughout the body. When lead is present in the body, it inhibits heme from forming which then deprives the body’s organs from needed oxygen. In addition to restricted oxygen, lead exposure can also induce anemia, which is a reduction in blood cells. The reduced heme in the blood stream decreases the amount of iron, which depletes the level of red blood cells. Red blood cells typically remain active for up to 120 days, but an increased amount of lead reduces the lifespan. Once this occurs the body’s bone marrow is unable to create red blood cells at the needed rate, which can lead to infection, fatigue, organ damage and malnutrition (Levin et al., 2008). Children can experience a variety of complications and health concerns because of an increased level of lead in the blood stream.

The Central Nervous System

The central nervous system is directly related to the body’s interaction with the outside world. It is made up of the brain and spinal cord, which both are important to survival. The

ingestion of lead, as noted earlier, leaches itself into the gray matter of the brain. The effects on the brain can have lasting and damaging concerns for a developing child. The child’s brain is still emerging and the reduction in brain function can decrease the ability of the brain to communicate with the remainder of the body. The Central Nervous System is especially sensitive to elevated lead levels. The most functional part of the nervous system is the neuron, which moves signals between locations. In order to communicate the message the dendrite receives and relates it to the rest of the neuron (Canfield, 2003). The synaptic terminals then use chemical messengers or neurotransmitters to send the message to other areas. Calcium ion is important to the nervous messaging system and provides the ability for the electrical pulses into chemical signals (Canfield, 2003). Cells absorb lead in the same manner that calcium is which inhibits the calcium, therefore disrupting chemical messengers. With an inhibited amount of calcium absorption the body is unable to convert the electrical pulses and blocks pruning, or the shaping of the brain in children (Canfield, 2003). Lead is able to cross the blood brain barrier and also allow other toxins to cross, which can lead to brain edema, or swelling. This can lead to speech, language, and behavioral problems.

The Renal System

Lead exposure can create lasting damage to the kidney system of children. The kidneys have an increased exposure to lead because it is the primary location of elimination. In the past, research was aimed primarily at higher levels of lead exposure. In recent studies, it has been

discovered that lower levels or extended periods of exposure can also lead to kidney disease. Toxic effects can lead to nephropathy which decreases the kidneys ability to remove waste from the body. This occurs because nephrons, small units that make up the kidney, are damaged and

reduced through exposure to toxins, such as lead. With a decrease in nephrons, the kidneys become damaged and can lead to disorders such as high blood pressure, congestive heart failure, nerve damage, malnutrition and many others (Abboud & Henrich, 2010). The ultimate detriment is renal failure whereas there is a decrease in glomerular filtration rate, which increases abnormal fluid levels within the body. Within elevated levels of fluid there are higher than normal levels of calcium, potassium, which can lead to additional health problems such as anemia. Higher levels can also lead to uric acid excretion which can cause medical conditions such as gout, or recurrent inflammatory arthritis. With increased levels of uric acid and other toxins not properly filtered by the kidneys the individual can suffer from bone damage, muscle paralysis and abnormal heart patterns (Abboud & Henrich, 2010).

Contaminated Soil, Plants & Animals

Lead is commonly found in a number of environmental products. One of the primary sources is soil and plant lead contaminants in leaded gasoline between 1920 and 1974(Berger, Noah & McLynch, 2006). Lead was added to gasoline in those years to improve vehicle motor efficiency, however the exhaust from the vehicles was contaminating the soil, plants and animals that were near heavily traveled areas. Lead absorbs into the soil and then through the life cycle it can indirectly contaminate food supply and therefore children. While exhaust was a primary concern for soil and plant contamination, other issues such as deteriorating lead paint were also a problem source. As the lead is deposited into the soil, it is unable to travel or break down, which then becomes a part of the agricultural process. Animals are also affected as they graze in fields where lead has become a part of the soil and plants.

In conclusion, lead is a heavy metal that contaminates a variety of areas of human life.

Even the smallest amounts of lead indirectly or directly consumed by children can lead to serious health concerns. Children are most commonly exposed through hand to mouth consumption of paints chips containing lead. Indirectly, children are exposed to lead through food, candy, containers, soil as well as many others. The negative effects have long been established, however in recent research it has been noted that even low levels of lead can negatively affect a child’s behavior, medical as well as disturb cognitive abilities. Both the State and Federal government are leading research and preventative measures to protect children, however additional measures need to be taken. Along with continued research, programs must be enacted to eliminate lead based paint from older homes, as well as identify environmental areas containing high lead content. Parents, educators and health care professionals need to be well educated in educating, preventing and exploring resources for at risk children. This will enable parents to be more aware of lead within their own homes and environment, therefore use more caution. Knowledge will assist in the prevention of health detriments because of lead exposure.

Further Research

Continued research as well as preventative measures must be continued. Federal and State monies should be allotted to assist individuals in removing lead based paint, as well as clearing high levels of lead content. Additional enforcement needs to be addressed to monitor and ensure that products containing high levels of lead are not being imported or sold in the United States, especially those marketed for children. If products contain lead, the manufacturers and sellers should be required to identify the lead content as well as disclose the potential dangers of human consumption through indirect or direct exposure.

References

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