Hunt for Truth – Types of Lead

Elemental Lead 

Elemental lead (aka, metallic lead), is the form of lead used in the manufacture of ammunition. Metallic lead is rarely found naturally occurring in the environment.  The mineral form of lead found in nature is predominantly galena (PBS), which is processed in ore and extracted to produce metallic lead.  Presently, over half of the production of lead worldwide comes from recycled lead.

Metallic lead is naturally a bright and silvery metal that tarnishes to a dull grey when exposed to oxygen.  Favorable characteristics of elemental lead include its high density, soft and malleable properties, low electrical conductivity, as well as its high resistance to corrosion.

Elemental lead’s resistance to corrosion makes it ideal for products used outdoors or around water.  In the environment, metallic lead slowly forms a very thin oxide coating when exposed to air.  This coating envelopes the lead, protecting it and preventing further oxidation and renders it highly resistant to corrosion.  Accordingly, metallic lead is rather inert in the environment. Therefore, it tends to not be bioavailable to biological systems or to migrate in the environment, unlike industrial compounds of lead.

Compounds of Lead

Unlike metallic lead, industrial lead compounds are highly soluble in the digestive tract of wildlife. Lead compounds are formed when lead is combined with a variety of different elements, which provide favorable industrial characteristics. These lead compounds have long been used in many different applications. However, use in industrial applications renders the lead in a much more soluble form than metallic lead. Lead compounds are, therefore, readily absorbed within biological systems. In other words, the high rate of solubility of industrial lead compounds make them readily bioavailable to humans, plants and animals. It is this ready bioavailability of soluble lead compounds that is responsible for the high toxicity of lead based paints, gasoline and pesticides. Other common applications of lead compounds include ceramic glazes, PVC coatings, and cosmetics. All of these different formulations of lead compounds drastically increase the solubility and, as a result, the bioavailability of lead. Industrial lead compounds are problematic for wildlife when used in the environment. Indeed, Condor Recovery Program (CRP) biologists observed California Condors 317 and 318 (all birds are numbered by the CRP) in Pinnacles National Monument eating lead-based paint fragments that had flaked from the North Chalone Fire Lookout Tower. These Condor parents subsequently fed the regurgitated paint fragments to their offspring (550). Condors 317, 318 and 550 were all tested and found to have high blood-lead levels. Because of the ready bioavailability of lead compounds in lead-based paint, 550 had to be evacuated to the Los Angeles Zoo for intense treatment for lead poisoning. 

Diagnosis and Treatment

Lead poisoning has very nonspecific symptoms, including abdominal pain, peripheral neuropathy, weight loss, and gastrointestinal problems.  These symptoms are shared by other heavy metal poisonings, namely zinc and copper toxicosis, making diagnosis difficult without laboratory tests to determine the nature of the heavy metal poisoning.

Lead poisoning is clinically diagnosed in part by blood-lead level measurements.  Other forms of diagnosis include x-ray to determine the extent lead has infiltrated the bone tissue, and histological examination.

Typically, when elevated blood lead-levels exceed 45 µg/dL in humans and 50 µg/dL in animals, chelation therapy is used for treatment.  Chelation therapy is the administration of chelating agents to remove excessive heavy metals from the body and bloodstream. The chelation agent attaches itself to lead circulating in the blood and allows the kidneys to filter and remove the lead from the blood.

In humans, chelation is generally administered either orally or intravenously. Due to the propensity of chelating agents to remove all metals from humans and animals, chelation treatments should not be performed without direct supervision of qualified medical or veterinary personnel.

Notwithstanding the general preference for oral or intravenous chelation in the medical community, the Condor Recovery Team personnel have been discovered administering chelation treatment to California condors intra-muscularly. Evaluations are ongoing as to the extent of the harm to California condors caused by intra-muscular injections of Calcium EDTA by Condor Recovery Team personnel.

The most commonly used chelating agents are known to cause visceral gout and kidney damage in birds with impaired renal functions, and when improperly administered. Despite the known risks of this treatment, the Condor Recovery Team personnel routinely administered chelation therapy where lead fragments are not found in the condor and where the condor’s blood-lead level are well below clinical levels. As a result, numerous of California condors have been injured and some have died due to visceral gout. Nevertheless, condors continue to receive mis-applied chelation treatments administered by unlicensed individuals in the field, instead of being administered by a veterinarian in a clean, controlled environment.

Hunt for Truth is currently researching  the extent of condor mortalities and harm related to the mis-application of chelation treatments by unlicensed and unqualified Condor Recovery Team personnel.

Exposure To Lead In The Environment: Metallic Lead Does Not Share Same Toxic Qualities As Qualities as Industrial Lead 

On the ground in the environment, metallic lead from ammunition slowly reacts with oxygen, forming a thin oxide layer of “tarnish” that envelopes the lead and protects it from further oxidation. As a result, the lead can remain on the ground in the environment for a very long period of time in an essentially inert state. The alkaline nature of most soils, particularly in the Western United States, protects the lead and renders the metallic lead quite resistant to oxidation when exposed to water. In addition, any small particles of lead that may occur are quickly bound by the clay layers of the soil which prevents the lead from migrating. Thus, bullets on the ground in the environment, such as resulting from hunting activities, are essentially inert and not a cause for concern.

The solubility of lead is an important factor in determining the relative bioavailability of lead that has been ingested by wildlife. Fortunately, wildlife does not ingest spent lead bullets that are lying on the ground. Although studies have shown that about 3% of doves may ingest a few lead shot pellets incidental to feeding, other studies have indicated that such incidentally ingested pellets are rapidly passed out of the digestive tract without resulting in poisoning.

Even in experiments where lead is deliberately fed repeatedly to wildlife with food, it has been shown that it is very difficult to poison the animals. This lack of bio availability of metallic lead is attributed to the combination of metallic lead’s insolubility as well as the buffering of the stomach acid with food and the rapid passage of the food bolus out of the stomach into the neutral intestinal tract.

In a publication directly on point, researchers attempted to poison turkey vultures with lead shot by continuously feeding six turkey vultures large amounts of lead shot. When the birds excreted the shot, the researchers cleaned and re-administered the shot to the birds, with the goal of determining the amount of time necessary for a turkey vulture to succumb to lead poisoning.  After 211 days of being continuously fed significant amounts of metallic lead in their food, four of the six turkey vultures in the study showed few signs of lead poisoning.  Only when very large amounts of lead were continuously administered for 143 days were the researchers able to induce a fatal lead poisoning in two of the six turkey vultures in the experiment.  This experiment clearly shows how difficult it is for wildlife to be poisoned by food containing lead ammunition.

Thus, metallic lead (insoluble lead), such as used in ammunition, has a minimal bioavailability in wildlife.

In stark contrast, many forms of industrial compounded lead, such as the lead in paint chips or environment contaminated with legacy leaded gasoline or leaded pesticides are quite soluble in the digestive tract of wildlife. This ready bioavailability constitutes a substantial environmental threat.

In addition to direct ingestion of industrial lead (soluble lead) contaminated items in the environment, lead poisoned livestock can concentrate a form of highly soluble, toxic lead compounds in the internal organs of their body. When carcasses of such lead poisoned livestock are ingested by scavenger wildlife, such as the California condor, these organs can provide very high levels soluble lead to the wildlife, resulting in poisoning.

LEAD ANALYSIS

Elemental

Elemental lead analysis of ammunition, often referred to as Compositional Analysis of Bullet Lead (CABL), was a technique used in forensic science for almost 20 years before it was abandoned for being non-specific. The FBI used the CABL technique to compare projectiles from a crime scene to projectiles from a specific box of ammunition. The FBI would then use the analytical data as evidence to convict an alleged perpetrator of a crime. The FBI’s methodology, however, was inherently flawed because it relied on specific trace elemental composition of lead, which eventually proved to be similar across all ammunition in numerous boxes made from that specific batch of lead. A study conducted in 2004 by the National Research Council of the National Academy of Sciences concluded that “CABL does not, however have the unique specificity of techniques such as DNA typing to be used as standalone evidence,” leading to their recommendation that CABL not be used as conclusive evidence for a conviction. Accordingly, elemental lead analysis was proven to be “faulty science” in tracing lead in ammunition back to a specific source.

Isotopic

Isotopic compositional analysis is alleged to be yet another forensic science technique for tracing lead in ammunition back to a specific source. Lead contains four stable isotopes found in the environment, including 204, 206, 207 and 208. The isotopic ratios of these four lead isotopes is claimed to conclusively prove “fingerprinting” of the source of lead poisoning in an organism. Although this technique is alleged by a few naïve scientists to be capable of matching blood-lead isotopic ratios found in an organism to specific sources of lead found in ammunition, the realities of lead metallurgy and lead product manufacture show conclusively that such matches cannot legitimately be made.