In addition to jeopardizing the health of children, lead poisoning can also worsen liver disease. Because this toxic metal has infiltrated the modern lifestyle, awareness of how it impacts the liver, where it is most prevalent and how to reduce its impact is crucial for those with liver concerns.
We must all be cognizant of the dangers of lead. Due to its documented dangers for childhood development, the concern over kids’ exposure to lead is nothing new. While children are particularly susceptible to the effects of lead poisoning, people living with chronic liver disease should also be on a vigilant lead alert.
Liver and Toxins
One of the liver’s many life-sustaining functions is filtering any circulating toxins out of the bloodstream. Those living with chronic liver disease either have less of their liver available to filter toxins, or are striving to prevent this sign of advancing illness. With fewer functioning liver cells prepared to purify the blood, toxins accumulate in the liver and bloodstream. In addition to the danger of high concentrations of toxins in the blood, this backlog of poisons in the liver can actually kill hepatic cells, accelerating liver deterioration. For individuals managing liver disease, minimizing toxin exposure is akin to preserving their liver’s health.
Lead is the most abundant toxic heavy metal. World production exceeds 3.5 million tons per year. Lead poisoning is a result of exposure to lead in the environment. Exposure primarily occurs from lead’s presence in air, food, water, soil, dust fall, paint and other materials. For the most part, lead is no longer used to manufacture paints, gasoline, water pipes and other products. However, a lot of lead-based products are still in existence, posing a credible health hazard. The most common sources of lead poisoning in the United States are lead-contaminated house dust from lead pipes and deteriorated lead-based paint in older homes.
Lead is readily absorbed by the body via the primary routes of entry, inhalation and ingestion. Because this toxic metal is highly absorbed by children, lead poisoning concerns are typically focused on kids. In children, approximately 50 percent of ingested lead is absorbed into the blood as compared to 20 percent for adults. Since children are most likely to put dirty hands and other objects into their mouths, lead exposure via ingestion is especially hazardous. Studies indicate that regardless of age, 10 to 20 percent of inhaled lead enters the blood stream.
While lead exists in both organic and inorganic forms, the organic form is most dangerous to those with liver disease:
1. Inorganic Lead – The lead found in old paint, soil and various other products is inorganic lead. Most lead encountered in the environment today is inorganic.
2. Organic Lead – Leaded gasoline contained organic lead before it was burned; however, since the elimination of lead from gasoline in the U.S. starting in 1976, exposure to organic lead is generally limited to an occupational context. Though, organic lead can be more toxic than inorganic lead because the body more readily absorbs it.
Organic Lead Exposure
The major routes of exposure to organic lead involve inhalation and ingestion of lead-bearing dust and fumes. Workers in the lead smelting, refining and manufacturing industries experience the highest and most prolonged occupational exposures to lead. Increased risk for occupational lead exposure occurs among:
· battery manufacturing plants
· construction workers – especially renovation/rehabilitation
· rubber products and plastics industries
· steel welding/cutting operations
· bridge maintenance and repair workers
· municipal waste incinerator workers
· people who work with lead solder
· radiator repair mechanics
· pottery/ceramics industry employees
Lead in the Body
The neurological system is most susceptible to lead exposure. Scientific studies clearly indicate that lead poisoning is associated with a significant decline in nervous system development and causes neurobehavioral anomalies.
The different forms of lead are metabolized differently by the body. While inorganic lead is not metabolized by the liver, organic lead is. Nearly all organic lead that is ingested is absorbed into the bloodstream. Therefore, people with liver disease must be extremely cautious about organic lead exposure. However, excessive exposure to inorganic lead will accumulate in the body, increasing a person’s overall toxicity load. The neurological system is most susceptible to inorganic lead exposure.
Within the body, lead is found in circulating red blood cells, liver, kidney and bone tissue. Blood lead concentrations are the most reliable indicator of recent lead exposure. The documented health effects of lead poisoning include:
· brain and nervous system damage
· severe kidney injury or failure
· injury to the gastrointestinal system and the heart
· damage to the reproductive system
· high blood pressure
Lead and the Liver
While repeated studies have documented the relationship between lead exposure and hypertension, few realize how this impacts liver health. The evidence shows that the link between this toxic metal and hypertension is due to lead having a direct effect on blood vessel and smooth muscle contractility. For those with cirrhosis and its typical consequence – portal hypertension – lead exposure may worsen this increase in vascular pressure.
A peer-reviewed study on lead exposure demonstrated another pathway for this metal’s perpetuation of liver damage. As published in the April 2006 issue of Environmental Health Perspectives, researchers found that lead could activate signals that increase tumor necrosis factor-Î±, a substance in the liver that causes inflammation, malignancy and cell death.
The Risk of Lead
While the risk lead poses to children is globally understood, those with liver disease are equally vulnerable to lead exposure. Some ways to identify and reduce the risk of lead poisoning include:
· Choose Your Job Wisely – Because it is readily absorbed, a person with a compromised liver puts him or herself at great risk if employed in an occupation where organic lead is handled. If in such a position, take advantage of every level of protection possible.
· Test Your Home – Since household dust is one of the biggest contributors to inorganic lead exposure, testing the environment can help someone detect, locate and eliminate the source of lead.
· Strengthen Your Liver Cells – Since lead levels accumulate in the body, strengthen liver cells to reduce their vulnerability to this toxin. Supplementing with milk thistle is proven to promote liver health by strengthening the outermost layer of hepatic cells.
While lead has contributed to the development of our modern lifestyle, it also poses a significant threat to our lives. Especially important for children and people with chronic liver disease, we must protect ourselves from lead exposure. Whether occupational or environmental risks threaten your liver, educate yourself on reducing lead exposure and insulating your liver from its toxicity.
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www.atsdr.cdc.gov, Lead Toxicity, Department of Health and Human Services Agency for Toxic Substances and Disease Registry, 2007.
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www.environmentaldiseases.com, Lead Toxicity: Low-Level Environmental Exposure, Nachman Brautbar, M.D, 2007.
www.epa.gov, Lead (Pb), US Environmental Protection Agency, 2007.
www.mayoclinic.com, Lead Poisoning, Mayo Education for Medical Education and Research, 2007.
Yu-Jung Cheng, et al., Lead Increases Lipopolysaccharide-Induced Liver Injury through Tumor Necrosis Factor-Î± Overexpression by Monocytes/Macrophages: Role of Protein Kinase C and p42/44 Mitogen-Activated Protein Kinase, Environmental Health Perspectives, April 2006.