72. Chemical hazards in the workplace – heavy metals. Occupational health risk. Prevention.

What processes give rise to metals in absorbable forms at workplaces?

• Metal ore extraction

• Metal smelting

• Metal founding

• Metal machining

• Hot metal processing

• Welding, soldering, brazing, thermal cutting

• Handling powerful metallic salts

How does metal toxicity vary?

• Depends on metal form: native, salt, ion

• Chemical valence

• Whether inorganic or organic compound

What are the primary industrial uses of lead?

• Lead batteries

• Automotive paints

• Solders

• Metal alloys

• Bearings

How are workers exposed to inorganic and organic lead?

• Inorganic: mining, refining, battery industry, radiator repair, paint spraying

• Organic: petroleum workers (tetramethyl/tetraethyl lead)

How is lead absorbed and excreted in the body?

• Inhaled/ingested small particles cross alveolar walls to bloodstream

• Accumulates mainly in bones

• Excreted primarily via kidneys

What are the main health effects of lead poisoning?

• Neurotoxicity

• Kidney dysfunction

• Hypertension

• Anemia

• Constipation

• Burton’s line on gums

• Fatigue

What is cadmium and its main industrial uses?

• White, ductile metal

• Used in nickel-cadmium batteries

• Electroplating steel

• Low melting point safety valves

Why is cadmium especially dangerous?

• Cumulative toxicant with biological half-life up to 30 years

• Targets kidneys after long-term exposure

What are acute and chronic effects of cadmium exposure?

• Acute: cough, headache, eye irritation, fever, chest pain, lung damage

• Chronic: kidney damage, respiratory system impairment

What are mercury's sources and primary target organs?

• From roasting cinnabar ore

• Thermometers (older types)

• Dental amalgams

• Fluorescent bulbs

• Targets CNS, kidneys, fetal tissues, breast milk

How does mercury cause toxicity?

• Precipitates proteins

• Inhibits sulfhydryl enzymes

• Causes CNS damage

What symptoms are associated with mercury poisoning?

• Headache

• Tremors

• Weakness

• Psychotic disorders

• Contact dermatitis from vapor exposure

What are arsenic's uses and main routes of exposure?

• Uses: lead alloys, pesticides

• Exposure: inhalation during ore smelting, ingestion, dust inhalation

What are acute and chronic health effects of arsenic?

• acute: hemorrhagic gastritis, cramps, edema, neuropathy, skin lesions

• Chronic: nasal irritation, dermatitis, heavy skin pigmentation

What cancers are associated with arsenic exposure?

• Lung cancer

• Respiratory tract cancers

What is chromium used for and which form is toxic?

• Uses: stainless steel, welding rods, tooling metals

• Toxic form: hexavalent chromium compounds

What health effects does chromium exposure cause?

• Dermatitis

• Ulcers

• Nasal septum perforation

• Larynx and liver inflammation

• Bronchitis

• “Chrome holes” (skin ulcers)

• Bronchogenic carcinoma

What is asbestos and what disease does it cause?

• Group of fibrous minerals (chrysotile most common)

• Used in insulation, roofing

• Causes asbestosis: lung fibrosis and cancer

What are key preventive measures for chemical hazards from heavy metals?

• Use new technologies and automation

• Hermetic industrial processes

• Adequate ventilation

• Exposure monitoring

• Worker education and training

• Personal protective equipment (PPE)

• Nutrition and medical check-ups