What are inorganic lead and organic lead?

Question

What are inorganic lead and organic lead?

Answer 1

Inorganic lead

Lead absorption from the gastrointestinal tract in both humans and experimental animals is  strongly influenced by age (neonates and the young absorb a larger fraction than adults), fasting/ fed status (fasting humans and experimental animals absorb much larger fractions than their fed   counterparts), nutrition (fat and caloric intakes; phosphorus, copper, zinc and especially iron and     calcium status, all affect lead absorption), solubility (soluble lead compounds are better  absorbed) and particle size (in controlled studies in rats, lead absorption from ingested mining  wastes was shown to be inversely proportional to particle size). There are no data indicating that  the fraction of lead absorbed from an inhalation exposure is dependent on the amount of lead in

the lung. Patterns and rates of particle deposition are highly dependent on particle size and  ventilation rate, but all lead deposited deep in the lung is eventually absorbed. Limited studies indicate that dermal absorption of inorganic lead is negligible, although slightly increased by high  perspiration rates in humans. In both humans and experimental animals, absorbed lead is rapidly distributed from blood  plasma simultaneously into erythrocytes, soft tissues, and bone. The half-life of lead in blood  and soft tissues is 20–30 days in adult humans and 3–5 days in adult rats. In both humans andand experimental animals.  Tetraethyl lead and tetramethyl lead are oxidatively dealkylated in the body. Any inorganic lead produced from these reactions is distributed in the same way as administered inorganic lead. In humans and rats exposed to alkyl lead, concentrations of lead are highest in the liver and  kidneys followed by the brain and heart. The rates of metabolite production are not known in

detail for either humans or experimental animals.

In humans, tetraethyl lead is excreted in the urine as diethyl lead, ethyl lead, and inorganic lead.  In rats and rabbits, dialkyl lead is the major metabolite found in urine. One of the end-products of  metabolism of tetraalkyl leads is inorganic lead, which is also excreted in the faeces. In humans, exhalation of unmetabolized tetraethyl lead and tetramethyl lead from the lung is a  major route of excretion.Toxic effects of inorganic lead  Typical clinical manifestations of lead poisoning include weakness, irritability, asthenia, nausea,

abdominal pain with constipation, and anaemia. Lead interferes with numerous physiological processes. In the haeme biosynthetic pathway, it inhibits d-aminolevulinic acid dehydratase (also known as porphobilinogen synthase), probably  through its high affinity for the zinc-binding site in the enzyme. Although lead displaces zinc