TRACE-CC
Arsenic Exposure
Environmental and Occupational Exposure
Common in industrialized areas and through air and water.
Found in agriculture and smelting industries.
Used in homicides and suicides.
Absorption and Clearance
Organic arsenic compounds absorbed rapidly through passive diffusion.
Clearance mainly through renal filtration of free, ionized arsenic.
High-affinity binding to thiol groups in proteins results in low filtration in serum and long half-life (cumulative effects).
Arsenic Compounds
Organic vs. Inorganic Forms
Nontoxic organic forms: arsenobetaine and arsenocholine cleared in 1-2 days.
Toxic inorganic forms include As(V), As(III), and methylated forms (MMA, DMA) formed by hepatic metabolism.
Methylated forms are less toxic but eliminated slowly (1-3 weeks).
Biological Exposure Index: sum of inorganic and methylated metabolites of arsenic is 35 µg/L, symptoms may not appear at this level.
Toxicity and Sources
Toxicity Profile
Inorganic arsenic is highly toxic, found in rocks, soil, and groundwater.
Methylated arsenic is of intermediate toxicity.
Organic arsenic is relatively non-toxic, found in fish, seaweed, and shellfish.
Arsenic trioxide (white powder) is a historical poison with doses of 0.01-0.05 g causing toxic symptoms; lethal dose: 0.12-0.3 g.
Clinical Effects
Symptoms of Exposure
Low-level exposure: fever, anorexia, gastrointestinal distress.
High exposure levels lead to nervous system damage, renal effects, and vascular disease (potentially fatal).
Analysis
Common methods: atomic absorption spectrophotometry (urine for acute exposure, hair/nails for chronic exposure).
Arsenic Treatment
Management Strategies
Includes gastric lavage and emesis.
Administer dimercaprol, followed by oral chelation therapy (penicillamine or 2,3-dimercaptosuccinic acid).
Cadmium Exposure
Sources and Absorption
Found in electroplating, galvanizing, paints, and batteries.
Common exposure through inhalation or contaminated food; higher levels found in smokers.
Toxic Mechanism
Binds to proteins; toxicity through denaturation of cadmium-bound proteins.
Blood cadmium mainly bound to RBCs (70%).
Toxicity Profile
Kidney Accumulation
Cadmium accumulates primarily in kidneys causing tubular proteinuria, glucosuria, and aminoaciduria.
Reference Intervals
Urinary cadmium: <2.6 µg/L (random), <3.3 µg/day (24-hr collection); blood: <5.0 µg/L.
Analysis
Determined by atomic absorption spectrophotometry.
Lead Exposure
Sources
Common in paints (pre-1972), auto exhaust, and lead plumbing.
Higher susceptibility in children; adults absorb 5-15%, while infants absorb 30-40%.
Toxicity Profile
Health Effects
Acute ingestion of 15g can be lethal.
Absorbed lead binds to various bodily macromolecules, accumulating in bones with a half-life >20 years.
Exposure results in cerebral edema, ischemia, and severe poisoning symptoms (stupor, convulsions).
Subclinical Effects
Cognitive Impact
Low-level exposure leads to behavioral changes, reduced IQ, and attention deficits, especially in children.
Treatment and Monitoring
Management of Lead Poisoning
Involves removal from exposure, chelation therapy (EDTA, DMSA), with efficacy monitored by urinary lead concentration.
Mercury Exposure
Forms and Routes of Exposure
Exists as elemental, inorganic, and organic (alkyl) mercury.
Exposure primarily through inhalation and ingestion.
Elemental mercury is less absorbed; toxic upon being converted to the divalent form.
Toxicity Effects
Symptoms
Describe gastrointestinal distress, renal failure, CNS effects.
Higher levels lead to severe toxicity, including death.
Analysis and Treatment
Detection Methods
Analyzed by atomic absorption, using blood or urine samples.
Treatment includes gastric lavage and dimercaprol.
Chromium Exposure
Properties and Uses
Essential for stainless steel production, exists primarily as Cr(III) and Cr(VI); the latter is more toxic.
Health Risks
Cr(VI) can cause severe skin reactions and respiratory issues.
Associated with lung cancer risk in occupational settings (printers, metal workers).
Measurement and Evaluation
Assessment of Exposure
Detected through GFAAS, NAA, or ICPMS.
Reference intervals inform on nephrotoxic effects.
Copper Exposure
Properties and Functions
Soft metal with a substantial role in various enzymes.
Found predominantly in liver, brain, heart, and kidneys.
Health Implications
Deficiency and Toxicity
Copper deficiency leads to conditions like Wilson’s disease, causing neurological and hepatic issues.
Iron Metabolism
Significance
Vital trace element, participates in redox reactions, predominantly stored in hemoglobin.
Assessment of Iron Levels
Methods and Normal Ranges
Measured via serum iron concentration and total iron-binding capacity (TIBC); essential in diagnosing iron overload and deficiency.
Manganese Exposure
Role in Industry
Essential for steel production; biochemically significant as a cofactor in enzymes.
Toxicity Profile
Health Effects
Chronic exposure leads to neurological issues resembling Parkinson's disease.
Molybdenum Overview
Characteristics and Absorption
Important metal used in alloys, absorbed mainly in the stomach and small intestine.
Health Concerns
Excessive Levels
Linked to elevated uric acid levels and gout.
Selenium Significance
Properties and Applications
Known for antioxidant properties and is used in various industries, including electronics.
Toxicity Manifestations
Acute and Chronic Effects
High exposure results in gastrointestinal and neurological issues.
Zinc Exposure
Importance and Dietary Sources
Critical trace element influencing enzyme activity; found in high concentrations in muscles and skeleton.
Toxicity and Analysis
Deficiency and Chronic Overconsumption
Excessive zinc may lead to gastrointestinal disorders and interfere with copper absorption.