Trace elements can be essential or toxic. Trace element toxicity can occur as a result of occupational exposure, environmental exposure or iatrogenic toxicity. Any organ can be affected: the central nervous system, liver, kidneys, muscles or circulatory system. All elements can be toxic in excess. Those most commonly associated with toxicity include: aluminium, lead, arsenic, cadmium, mercury, thallium, barium, germanium, tellurium, tin, antimony, osmium, uranium.
Lead is a non-essential element and toxic effects occur through its accumulation in the body, reflecting its extensive use in silver smelting, paint production, jewellery making, building construction, petrol use and its ubiquitous presence in the water supply. Acute poisoning is now uncommon, however, chronic poisoning may often be due to industrial exposure, ingestion of lead-containing paint/contaminated dirt in children, or ingestion of contaminated alternative herbal therapy.
Symptoms include abdominal pain, fatigue, weakness, (aplastic) anaemia, basophilic stippling of erythrocytes and peripheral neuropathy, maybe concentrating in bone.
EDTA (lavender top)
Guidance for industrial exposure to lead:
<1.9 μmol/L – repeat annually
>1.9 μmol/L – female employees should be removed from exposure to lead
1.9-2.8 μmol/L – repeat after 6 months
2.9-3.3 μmol/L – repeat after 3 months
>3.3 μmol/L – employee unfit for work
Organic lead exposure tends to produce neurological symptoms, whereas inorganic lead tends to produce abdominal pain and anaemia.