Get ready for a HEAVY subject, literally. Ryan and Toxo talk about the toxic mechanisms, signs of poisoning, and treatment of one of the worlds most ubiquitous poisons. This is a long, but interesting one, consider listening in chunks.

Excellent Review Sources

• Calello DP, Henretig FM. "Lead." In: Goldfrank's Toxicologic Emergencies, 10th ed, Hoffman RS, Howland MA, Lewin NA, et al (Eds), McGraw Hill Education, New York, 2015. p.1219.
• Toxic Substances Database for Lead: https://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=96&tid=22

Clinical Case from Today's Show

• Severe lead toxicity from retained bullet fragments:
• Weiss D, Lee D, Feldman R, Smith KE. "Severe lead toxicity attributed to bullet fragments retained in soft tissue." BMJ Case Rep. 2017;2017. doi:10.1136/bcr-2016-217351
• Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353372/

History of Lead

• Lead’s abundance has increased over time due to radioactive decay: https://iopscience.iop.org/article/10.1086/375492
• Its use spans currency, cosmetics, aqueducts, and even wine, contributing to societal impacts like the fall of Rome: https://pubmed.ncbi.nlm.nih.gov/14261844
• Lead in society overview: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6522252/

Common Sources of Lead Exposure

1. Lead Paint: Up to 50% lead until 1940; still present in millions of homes.
2. Soil: Contaminated by tetraethyl leaded gasoline (introduced by Thomas Midgley): https://interestingengineering.com/thomas-midgley-jr-the-man-who-harmed-the-world-the-most
3. Lead Piping:

• EPA Lead and Copper Rule: https://www.epa.gov/sites/production/files/2016-10/documents/508_lcr_revisions_white_paper_final_10.26.16.pdf

1. Traditional Medicines: Ayurveda: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2538609/
2. Kohl (cosmetics): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1567936/
3. Bullets: https://pubmed.ncbi.nlm.nih.gov/30939573/
4. The "Lead Crime Hypothesis": https://pubmed.ncbi.nlm.nih.gov/27035924/

Clinical Effects

• Ben Franklin’s "Dangles and Bellyaches": https://pubmed.ncbi.nlm.nih.gov/22910081
• Colic/constipation.
• Neuropathy.
• Neurocognitive/Behavioral Effects:
• IQ reduction, visual-spatial impairment, reduced processing speed, and irritability.
• Impacts in young children: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3909981/
• Chronic Conditions:
• Kidney and vascular disease: https://www.atsdr.cdc.gov/toxprofiles/tp13-c2.pdf
• Hematologic effects (e.g., hemolytic anemia): https://www.atsdr.cdc.gov/toxprofiles/tp13-c2.pdf
• Burton lines (sulfate deposits): https://www.amjmed.com/article/S0002-9343(12)00286-0/pdf
• Lead lines (metaphyseal calcification): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1912933/

Toxic Mechanisms

• Binds to sulfhydryl groups.
• Acts as a divalent cation, interfering with numerous enzymatic processes.
• Comprehensive overviews:
• Goldfrank’s Toxicologic Emergencies, 10th ed.
• https://www.atsdr.cdc.gov/csem/csem.asp?csem=34&po=10

Treatment Overview

Chelation Therapy:

• BAL: Painful IM injection; contraindicated in G6PD deficiency.
• https://www.sciencedirect.com/science/article/pii/S0041008X99987252
• Ca2NaEDTA: IV; used for levels >70 µg/dL or encephalopathy.
• https://www.sciencedirect.com/science/article/abs/pii/S0013935184710632
• Succimer: Oral; ensure lead has passed the small intestine before starting.
• https://www.sciencedirect.com/science/article/abs/pii/S0013935184710632

Management Based on Blood Lead Levels:

• Kids: https://www.cdc.gov/nceh/lead/advisory/acclpp/actions-blls.htm
• Adults: https://pubmed.ncbi.nlm.nih.gov/17431500/

If You Encounter Lead Exposure

• Confirm elevated capillary blood lead with venous testing.
• Call your toxicologist or poison center for guidance.

Thanks for listening!

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