Effect of lead on the musculoskeletal system

It is a chemical element which is denoted by Pb which has 82 atomic numbers. It is denser than other elements.

Therefore we also called it heavy metal.it is soft, ductile, or pliable and has a low melting point because it can easily be converted into liquid form even at low temperature.

 When we cut lead freshly its color changes. When lead is exposed to air or in the presence of oxygen its color change and it looks dull.

What is the musculoskeletal system?

The skeletal system is composed of ossein, gristle, brawn, ligaments, falciform ligament, and connective tissues. These components of the skeletal system help to stabilize our body and connect the tissues.

The skeletal system supports body weight. In addition to it, ossein and brawn work simultaneously to keep up the body posture. It also helps to make up controlled and exact or accurate movements.

Furthermore, to carry the mass of the body, ossein works in conjugation with muscles to nurture the stance of the body, and to give rise to retrained, exact movements.

Effect of lead on musculoskeletal system:

Lead is often present in our surroundings because of its frequent use in the environment.it can be stored in the soft tissues of the body.

Approximately all organ systems of our body are sensitive to lead exposure. If our body is exposed to lead even at a very low concentration such as 5 micrograms per decilitre can affect our tissues.

It will affect our normal body functions such as it will affect the growth of bone, development f teeth, and affect the number of bone minerals in the bone tissue, affect the mechanism of healing or fracture.

It will delay all these processes in the body or stops these processes. It can also affect the function of motor nerves.

Lead is used in paint industries, plumbing, and pesticides, and gasoline due to which our environment becomes polluted with a high level of lead.

 If it enters our body it will affect all cells, organs, and systems of the body and disturb their normal functioning and cause lethal effects in the reproductive system, nervous system, and excretory system.

 If lead is once deposited in the surroundings it cannot be easily broken down and it will hold tightly with the uppermost layer of the soil. If lead enters the body, it is isolated and hidden away and led out in the soft tissues or connective tissues.

The major pool of the reservoir in our body is the skeleton. In the skeleton, approximately 95% lead is present. And its half-life is approximately 20-30 years. Scientists made experiments on the lead stock in the body.

They described that 40-70% of lead in the blood is released from the skeletal repositories and causes diseases such as menopause endocrine diseases such as thyrotoxicosis. During these conditions, lead is released back into blood circulation.

Routes of exposure:

The primary way of lead due to which it enters into our body is oral ingestion. Approximately 99% of lead enters the body with the inhalation process. Lead exposure is greatly done by mouthing and holding which is the greatest threat to the children.

Due to these physiological changes, 5-10% lead is absorbed in the intestinal tract of adults, and 30-40% is absorbed in children. Lungs of the children are at high risk for the storage of lead than that of adults.

It can also be entered into the body through cuts or injuries that are exposed to the environment. After absorption, lead enters the blood. Lead that is entered into the body through inhalation is approximately 30-40%.

Lead levels in the body compartments:

Bioaccumulation of lead:

Due to its long half-life, lead accumulates in the body and also persists in the environment. Due to these reasons, we are frequently exposed to lead. Furthermore, the level of lead in nature is increasing rapidly which gives rise to increase body burden.

Blood levels:

In the bloodstream, 30 days is its half-life. The level of lead in the blood is sensitive for the short term of exposure.

Lead is inhaled or ingested into the body released into the bloodstream. And then 99% of it binds with red blood cells. Lead can pass through the brain and placenta. The half-life/ of lead-in

Skeleton and teeth:

Lead shows a high harmony for those tissues which have a large amount of calcium in the skeleton and dentition due to having the ability to form chemical bonds with other elements because of its bivalent nature.

 During the formation of an outer thin covering of tooth and arrangement of teeth in the organism, the level of lead in the prenatal and postnatal makes a close relationship with the level of lead in the bloodstream. The level of lead in the bone and teeth is a sign of long-term exposure to lead.

 Lead cannot be evenly distributed in the tissues of bone because they are not alike. X-ray fluorescence spectrometry is used to detect the level of lead in the bones of living organisms.

Synovial fluid:

It is a sticky or gummy substance that is present in the chambers of diarthrosis. Its main function is to decrease the abrasion during movement between the articular cartilages (soft tissue present at the ends of the bones) of diarthrosis.

The level of lead becomes high than the blood levels due to its high solubility when the pH of synovial fluid is low.

Articular cartilage:

It is soft and smooth tissue that is present at the ends of bones to form joints. It is found where joints form. Its main function is to minimize the abrasion and provides a smooth layer for conjugation and the transferral of burden.

For those individuals which have lead exposure, their articular cartilage contains a 40% greater amount of lead than that of calcium.

Skeletal effects of lead toxicity:

Decreased motor skills:

Those individuals which are exposed to the lead, their nerve transmission can interrupt both in young and old.

Lead can decrease the hemoproteins due to which cellular energy becomes weaken or damage and at last, it will repress the transmission of nerve impulses.

As a result, the function of motor neurons becomes disturbs and motor neurons will no longer be able to perform their proper functioning.

Suppression of 1, 25 dihydroxycholecalciferol:

Lead shows lethal effects on the skeletal system either directly or indirectly. For example, lead exposure can decrease the level of vitamin D. due to the low level of vitamin D, the disease will occur which is called osteoporosis.

This is a disease in which the density and quality of bone become reduced and as a result, the bone becomes hollow and porous. If an organism is exposed to lead by oral, it will repress its appetite due to which it will eat less food and as a result, less intake of vitamin D occurs.

Lead can bind with the active site of the proteins that uptake calcium in the intestinal mucosa. Lead is accumulating in the last part of the small intestine and absorption of vitamin D dependent calcium takes place in the duodenum.

Bothe these absorbed in the different organs within the body. Therefore we cannot say that lead will stop the synthesis of vitamin D by acting on the calcium relating to the calcium uptake in the intestine.

But lead stops the activity of the hydroxylase enzyme. The principal function of this enzyme is hydroxylation of vitamin D when the level of vitamin D is low.

Developmental effects:

The dispersal of lead in the closeness of the epiphyseal plate is clearly understood. Regression appears from lead effects on infantile fixation. When the growth plate becomes at the end of evolution, an exhibition of lead can cause disturbance in the enlargement of the skeleton.

When the cellular processes are disturbed due to lead, it can cause structural development in the body due to abnormal embryonic or fetal development, lessen the rate of bone development and height. The prenatal lead exhibition leads to the short birth lengths.

Lead also retards the ontogenesis of the cells that is present in the healthy cartilage. It also causes harmful effects on the escalation of formative cell embryonic cell or bone-forming cells and replies to the statutory factors of growth.

The enterprise of formative embryonic cells is vanquished and the rate of occurrence of the cells that provide new cells to the body that are damaged or lost is lesser due to the lead.

Osteoporosis:

It is a disease due to which bones become week and hollow. When a person with this disease even falls or bears a small force, its bones become fracture.

During the development of the skeletal system, even a short-term exposure to lead is at risk of this disease. But the skeletal system of adults is not vulnerable.

Osteoarthritis:

It is the decline of joint cartilage and the fundamental bone. It causes pain and ineptness, especially in the hip, knee, and thumb joints.

 Furthermore, crucial units of a molecule of the joint reveal openly to attack to lead. Those persons betray more chances of hurting pain disease and clumsiness who work refinery, bullion, lead-acid battery synthesizers, and erection workers.

 Health hazards from teeny-weeny revelation to lead:

When a living organism displays with lead even for a very short period various diseases occur such as:

  • Bellyache
  • Irregular and infrequent or difficult evacuation of the bowels
  • Fatigued
  • Cephalalgia
  • Irascible
  • Craving
  • Amnesia
  • fragility

The risk from extending subjection to lead:

When an individual vulnerable to lead for a long period following diseases takes place:

  • stomach-ache
  • stultification
  • enervated
  • absent-minded
  • abrade
  • retching
  • unwell

Reviewed by:
Dr. Muhammad Adnan Asghar (Ph.D.)
Chinese Academy of Sciences Fuzhou, Fujian