Heavy Metal Toxicity

Introduction

Iron ore mining: risks to humans from selenium levels

Heavy metal (HM) toxicity is a general term for metal concentrations in excess of blood concentrations that can cause undesirable side effects.[1] Humans either through inhalation of HMs or through dermal exposure. Environmental effects of HMs can lead to air pollution pollutes seawater waterways and can accumulate in plant crops seafood and meat and indirectly affect humans. Some works have increased the risk of exposure and toxicity to specific HMs[2].

Accumulating evidence indicates that all age groups and organs are susceptible to metal-induced toxic effects, although effects on the central nervous system are more severe and long-lasting in the developing and adult brain. For those severely affected, there are no clinically proven treatments Metal toxicity. [3]

• The toxicity of heavy metals (HMs) is underestimated in the community.
• Heavy metals can affect the nerve, pulmonary, cardiovascular, kidney, skin, reproductive and skeletal systems to varying degrees.
• Heavy metals can cause damage to proteins (eg, enzymes, DNA membrane lipids) and disrupt normal cellular function.
• Young children are more affected than adults.
• Affected pregnant women can pass toxic HMs to a developing fetus with great harm.
• Toxicity of HMs can be both acute and chronic [2].

HMs and the Nervous System

Brain dysfunction

Compared to other parts of the body, the brain is sensitive to HMs and gets a lot of pollution. If exposed to heavy metals for a long time, they can have harmful effects on the nervous system. Heavy metal toxicity is the cause of many neurodegenerative diseases such as Alzheimer’s disease Parkinson’s disease Amyotrophic lateral sclerosis Multiple sclerosis and attention deficit hypertensive disorder. There are data on significant associations or correlations between heavy metal exposure and neurotoxicity. This is thought to be due to: Oxidative stress; involvement of certain proteins/enzymes; disruption of normal secretion of neurotransmitters due to heavy metal exposure. The resulting disease impact and severity can be prevented by taking appropriate precautions [4].

Etiology

HMs are dense natural elements that endanger health through accumulation in the environment and organisms.

1. A common list of non-essential HMs causing toxicity includes arsenic (As) cadmium (Cd) lead (Pb) mercury (Hg)
2. Elements essential in trace amounts for various human cellular activities include: Cobalt (Co) Copper (Cu) Chromium (Cr) Iron (Fe) Manganese (Mn) Molybdenum (Mo) Nickel (Ni) Selenium (Se) and Zinc (Zn) .

Exposure to HMs can be natural or professional.

Epidemiology

HM toxicity is worldwide.

1. The incidence and severity of toxicity of individual heavy metals varies with geographic location, natural soil content, customs, industry location, regulatory measures to control pollution, medical facilities for testing heavy metal toxicity, and individual factors such as nutritional status and nutritional status. genetics.
2. When HM is released into the air, water or soil, it can be taken up by plants, crops eaten by cattle and fish, and eventually into humans to complete the food chain.
3. Industrial and workplace exposures can lead to heavy metal poisoning through inhalation, ingestion, or dermal contact [2].

Lead Toxicity

Lead Recovery: Highly Toxic Substance.

Common sources of potentially harmful lead are lead paint welded to the edges of food cans (more common outside the US), old bathtub plumbing, and imported tableware. [1] Occupational exposure to lead is one of the most prevalent overexposures. Industry and High potential risks include construction work, most smelter operations, radiator repair shops, and shooting ranges [2]. Lead particles may also be airborne in remodeling projects

• Young children need to be extra careful with lead-containing products because the minimum level at which lead is declared toxic (10 mg/dL) is less than for adults (24 mg/dL). [1] Infants have an unformed blood-brain barrier, through which lead diffuses easily. Children and infants are commonly exposed to lead Particles during floor activity and through the stages of hand-to-mouth development. [1]
• Adults are more likely to be exposed to lead during renovation of old homes, fabrication of brass bullets, welding of stained glass/pottery designs, and regular use of metal wick candles. [1][5]

Acute lead poisoning can cause gastrointestinal problems such as nausea and vomiting, loss of appetite, stomach cramps, and constipation. It can also cause sleep problems, fatigue, mood changes, headaches, joint/muscle aches, anemia, and decreased libido.

Long-term problems of lead exposure include neurological, genitourinary, and hematopoietic problems. Long-term exposure to lead can cause death [6].

Arsenic Toxicity

1889 newspaper advertisement – Scary!

Common sources of exposure with above-average levels of arsenic include near or within hazardous waste sites. Arsenic exposure can come from glass penetration, pesticides, wood preservatives, paints and during the smelting of copper, zinc and lead. Exposure to high levels of arsenic can cause death[1][5][2]

Long-term effects of arsenic exposure include gross pigmentation with hyperkeratinization wart formation dermatitis vasospasticity Raynaud’s phenomenon decreased rapid conduction lung cancer eye disease peripheral neuropathies brain damage laryngitis lung disease rhinitis and death [7].

Mercury Toxicity

Mercury in Fish

Exposure to mercury can be in the form of inhalation or topical contact through the skin. [1] Common sources of mercury exposure include mining production and transportation of mercury and mining and refining of gold and silver ore. High Mercury Exposure Can Cause Permanent Neurological and kidney damage. Another common source of mercury is through the food chain; an animal is exposed and passes it up the food chain through ingestion. [2][1]

Short-term effects of mercury poisoning include lung damage nausea vomiting diarrhea hypertension tachycardia rash and eye irritation.

Long-term exposure to mercury can make the nervous system vulnerable to damage. Brain and kidney damage are common with high levels of mercury exposure. Other common systemic side effects are irritability, shyness, tremor, vision and hearing problems, and memory loss [8].

Protecting the food chain from mercury contamination is an important task to protect human health. [9]

Characteristics/Clinical Presentation

Dog cleaned post mercury exposure

The characteristics of heavy metal poisoning are vague, as patients present according to the route and level of exposure.

1. Acute exposures are usually dramatic. Inhalation of HMs can cause respiratory symptoms, local contamination, skin damage and ingestion similar to acute gastroenteritis or dysentery.
2. Chronic exposure is more difficult to detect. Symptoms vary depending on the organ system involved. Typical findings may only be present in selected cases, while most may be nonspecific [2]. [7]

Treatment

Activated Charcoal

The patient is released from toxic exposure. Excretion of HM can be accelerated by gastric lavage with activated charcoal and skin decontamination. Supportive care can be in the form of intravenous fluids, oxygen ventilation, and circulatory support, as needed. severe hemodialysis plasma Exchange and extracorporeal membrane oxygenation (ECMO) may be necessary.

• The focus should be on prevention. In some cases, complete prevention is not possible and the aim should be to minimize contamination.
• Chelation agents used to treat HM toxicity are not without side effects. Some metal ions are redistributed to other tissues, such as the brain, thereby increasing neurotoxicity. Others chelate essential trace elements and create a deficiency state, while others can cause Liver toxicity [2]

Associated Co-morbidities

The following co-morbidities are not seen in all types of poisoning but are common:[10]

• Attention Deficit Disorder
• Alzheimer’s disease
• Amyotrophic Lateral Sclerosis (Lou Gehrig Yare) .
• Asthma
• Arthritis
• Autism Spectrum disorders
• Autoimmune disorders
• Candidiasis (Yeast Infection)
• Chronic Fatigue Syndrome
• Epilepsy
• Fibromyalgia
• Gulf War Syndrome
• Hypertension
• Insomnia
• Infertility
• Kidney disease
• Liver disease
• Multiple Sclerosis
• Parkinson’s
• Schizophrenia
• Thyroid Disorders

Physical Therapy Management

Physical therapy does little to deplete the body of heavy metals. There is currently no best evidence for treatment of patients with heavy metal poisoning. Physiotherapy aims to manage the side effects of heavy metal toxicity and associated comorbidities.