🌍 Environmental Health · Rapid Recall

Screening tests, diagnostic tools & most accurate treatments + easy mnemonics (Nelson Pediatrics 22nd Ed – Chapters 757-763)

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🌎 757 · Environmental Health & Children
πŸ” SCREENING / ASSESSMENT
β€’ Environmental history (Table 759.3): home age (lead paint if pre-1978), water source (well vs municipal), parental occupation, hobbies, location (industry, fracking, highways), mold, radon, pica, tobacco smoke.
β€’ Lead screening: venous BLL at 12 & 24 months (universal or targeted based on local prevalence).
β€’ Mycotoxin risk: water-damaged home (Stachybotrys), moldy peanuts (aflatoxin), corn-based products (fumonisin).
🩺 DIAGNOSTIC TESTS
β€’ Lead: venous blood lead level (BLL) – confirm capillary β‰₯3.5 ΞΌg/dL.
β€’ Arsenic: 24h urine arsenic (<50 ΞΌg/L normal).
β€’ Mercury: whole blood (acute) or 24h urine (chronic).
β€’ PFAS/phthalates: no routine clinical testing; biomonitoring in research.
πŸ’Š MOST ACCURATE TREATMENT
β€’ Lead (BLL 45-69): succimer (DMSA) 10 mg/kg PO q8h x5d β†’ q12h x14d.
β€’ Lead (BLL β‰₯70 or encephalopathy): BAL + EDTA.
β€’ Arsenic acute: BAL 3-5 mg/kg IM q4h β†’ succimer.
β€’ Inorganic mercury: BAL + succimer.
β€’ Methylmercury: NO BAL (redistributes to brain); supportive care.
πŸ“Œ MNEMONIC β€œCHILD”
Child vulnerability (higher exposure/kg) β€’ Home age (lead) β€’ Industrial toxins (PFAS) β€’ Lead BLL 3.5 β€’ Decontamination + chelation (BAL/succimer).
🍽️ 757 · Food-Borne Toxins
πŸ” SCREENING / ASSESSMENT
β€’ History: incubation period (<6h preformed toxin; >6h amatoxin, botulism).
β€’ Fish/seafood: ciguatera (barracuda, grouper) β†’ cold allodynia; scombroid (tuna) β†’ flushing.
β€’ Mushrooms: identify species, spore print.
β€’ Aflatoxin: suspect with hepatitis after moldy peanuts/corn.
🩺 DIAGNOSTIC TESTS
β€’ Ciguatera/scombroid/PSP: clinical diagnosis; no routine lab test.
β€’ Amatoxin (mushroom): liver function tests (AST, ALT, INR), renal function.
β€’ Botulism: mouse bioassay or PCR (stool, serum).
β€’ Arsenic/mercury: 24h urine collection.
πŸ’Š MOST ACCURATE TREATMENT
β€’ Ciguatera: IV mannitol 0.5-1 g/kg within 48-72h.
β€’ Scombroid: antihistamines (diphenhydramine).
β€’ Amatoxin: activated charcoal (repeated), silibinin IV, NAC.
β€’ Paralytic shellfish (saxitoxin): respiratory support, mechanical ventilation.
β€’ Botulism: heptavalent antitoxin (HBAT) + respiratory support.
πŸ“Œ MNEMONIC β€œTOXIN”
Time (latency: <6h vs >6h) β€’ Organism (fish, shellfish, mushroom) β€’ Xenobiotic (mannitol for ciguatera, atropine for muscarine) β€’ Identify (spore print) β€’ Neutralize (antitoxin for botulism).
☒️ 758 · Ionizing Radiation Effects
πŸ” SCREENING / ASSESSMENT
β€’ Exposure history: dose (Gy/Sv), time to symptoms (prodromal nausea/vomiting).
β€’ Absolute lymphocyte count (ALC) within 48h: <500 = severe; <100 = lethal without transplant.
β€’ Pediatric CT dose reduction: ALARA principle, use ultrasound/MRI when possible.
🩺 DIAGNOSTIC TESTS
β€’ Acute radiation syndrome (ARS): CBC with differential, electrolytes, coagulation panel.
β€’ Internal contamination: whole-body counting, urine bioassay (tritium, cesium).
β€’ Bone marrow dose: chromosomal aberration analysis (dicentric assay).
πŸ’Š MOST ACCURATE TREATMENT
β€’ Hematopoietic syndrome (>0.7 Gy): G-CSF (filgrastim), transfusions, antibiotics.
β€’ Radioactive iodine (I-131): potassium iodide (KI) within 12-24h (neonate 16 mg, 1mo-3y 32 mg, 3-18y 65 mg, adult 130 mg).
β€’ Cesium-137 / thallium: Prussian blue (Radiogardase).
β€’ Tritium (H-3): forced fluids (dilution therapy).
πŸ“Œ MNEMONIC β€œRADIATE”
Remove clothing (decontamination) β€’ ALC (lymphocyte count) β€’ Dose (Gy) β€’ Iodine (KI for radioiodine) β€’ Antidotes (Prussian blue) β€’ Transfusions + G-CSF β€’ Evacuate.
πŸ§ͺ 759 Β· Chemical Pollutants
πŸ” SCREENING / ASSESSMENT
β€’ Environmental history (Table 759.3): home age (lead), well water (arsenic), occupation, hobbies, location (industry, fracking).
β€’ Lead: venous BLL at 12 & 24 months.
β€’ PFAS: no routine screening; test drinking water near industrial sites.
🩺 DIAGNOSTIC TESTS
β€’ Lead: BLL; zinc protoporphyrin (ZPP) for chronic exposure.
β€’ Organophosphates: RBC cholinesterase (depressed).
β€’ Arsenic: 24h urine arsenic.
β€’ Phthalates/BPA: urinary metabolites (research).
πŸ’Š MOST ACCURATE TREATMENT
β€’ Lead (BLL β‰₯45): succimer (DMSA).
β€’ Organophosphate poisoning: atropine 0.05-0.1 mg/kg + pralidoxime 25-50 mg/kg.
β€’ Cyanide (smoke inhalation): hydroxocobalamin 70 mg/kg IV.
β€’ PFAS: no established treatment; prevention (avoid non-stick cookware, stain-resistant carpets).
πŸ“Œ MNEMONIC β€œCHEM”
Child's environment (home age, water) β€’ History (pica, occupation) β€’ Exposure (lead, arsenic, OP) β€’ Management (succimer, atropine+pralidoxime, hydroxocobalamin).
🚬 759.1 · Tobacco
πŸ” SCREENING / ASSESSMENT
β€’ Ask all caregivers and youth: β€œDoes anyone in the home smoke or vape?” (CEASE model).
β€’ Youth tobacco use: screen starting age 11 (ACT model).
β€’ Serum cotinine (biomarker of exposure).
🩺 DIAGNOSTIC TESTS
β€’ Clinical diagnosis: secondhand smoke exposure β†’ asthma exacerbations, otitis media, LRTI.
β€’ EVALI (vaping): chest CT (ground-glass opacities), rule out infection.
πŸ’Š MOST ACCURATE TREATMENT
β€’ Caregiver smoking: nicotine replacement therapy (patch + gum) + Quitline referral (CEASE).
β€’ Youth smoking/vaping: nicotine patch + behavioral counseling (ACT model).
β€’ EVALI: corticosteroids, respiratory support, stop vaping.
πŸ“Œ MNEMONIC β€œQUIT”
Question (ask every visit) β€’ Use pharmacotherapy (NRT patch) β€’ Intervene (counsel) β€’ Tobacco 21 law (prevention).
☣️ 760 · Heavy Metals (Arsenic, Mercury)
πŸ” SCREENING / ASSESSMENT
β€’ Arsenic: test well water, rice intake. Mees lines (transverse white nail bands).
β€’ Mercury: elemental (thermometers), inorganic (batteries), methylmercury (fish).
β€’ Acrodynia (pink disease): mercury hypersensitivity.
🩺 DIAGNOSTIC TESTS
β€’ Arsenic: 24h urine arsenic (>50 ΞΌg/L abnormal); blood arsenic (acute).
β€’ Mercury: whole blood (methylmercury), 24h urine (inorganic/elemental).
β€’ Abdominal X-ray: radiopaque metal (button battery, elemental mercury).
πŸ’Š MOST ACCURATE TREATMENT
β€’ Arsenic acute: BAL (dimercaprol) 3-5 mg/kg IM q4h β†’ succimer.
β€’ Inorganic mercury: BAL + succimer.
β€’ Methylmercury: NO BAL (redistributes to brain); supportive care.
β€’ Acrodynia: remove mercury source; no chelation.
πŸ“Œ MNEMONIC β€œMEES” for Arsenic
Mees lines (nails) β€’ Exposure (well water, rice) β€’ Enteritis (vomiting, diarrhea) β€’ Sensory neuropathy (BAL+succimer).
⚠️ 761 · Lead Poisoning
πŸ” SCREENING / ASSESSMENT
β€’ Universal/targeted BLL: at 12 and 24 months.
β€’ Risk factors: pre-1978 housing, low-income, recent immigrant, pica, Medicaid.
β€’ Capillary BLL β‰₯3.5 ΞΌg/dL β†’ confirm with venous.
🩺 DIAGNOSTIC TESTS
β€’ Venous BLL (gold standard).
β€’ Abdominal X-ray (KUB): if BLL β‰₯20 or pica (retained lead chips).
β€’ Iron studies, CBC (anemia, basophilic stippling).
πŸ’Š MOST ACCURATE TREATMENT
β€’ BLL 45-69 ΞΌg/dL: succimer (DMSA) 10 mg/kg PO q8h x5d β†’ q12h x14d.
β€’ BLL β‰₯70 or encephalopathy: BAL 4 mg/kg IM q4h + EDTA (CaNa2EDTA) IV.
β€’ Abdominal X-ray + lead chips: whole bowel irrigation (polyethylene glycol).
β€’ Nutrition: calcium (1 g/day), iron (6-12 mg/day).
πŸ“Œ MNEMONIC β€œLEAD”
Level (BLL 3.5 reference) β€’ Environment (abatement) β€’ Abdominal X-ray (if pica) β€’ DMSA (succimer) for BLL β‰₯45.
πŸ„ 762 Β· Food Poisoning (Nonbacterial)
πŸ” SCREENING / ASSESSMENT
β€’ Incubation period: <6h (scombroid, muscarine) vs >6h (amatoxin, botulism).
β€’ Mushroom identification: spore print, mycologist.
β€’ Fish history: barracuda (ciguatera), tuna (scombroid), pufferfish (tetrodotoxin).
🩺 DIAGNOSTIC TESTS
β€’ Amatoxin: LFTs, INR, creatinine.
β€’ Botulism: mouse bioassay, PCR (stool, serum).
β€’ Ciguatera/scombroid: clinical diagnosis.
β€’ Melamine (urinary stones): renal ultrasound.
πŸ’Š MOST ACCURATE TREATMENT
β€’ Amatoxin: activated charcoal (repeated), silibinin IV, NAC.
β€’ Gyromitrin (seizures): pyridoxine 25 mg/kg IV.
β€’ Muscarine (cholinergic): atropine 0.01-0.02 mg/kg IV.
β€’ Ciguatera: IV mannitol.
β€’ Scombroid: antihistamines (diphenhydramine).
β€’ Tetrodotoxin: respiratory support, mechanical ventilation.
πŸ“Œ MNEMONIC β€œLATE vs EARLY”
LATE (>6h): Liver failure (amatoxin) β†’ Liver protect (silibinin+NAC).
EARLY (<6h): Emesis + flushing (scombroid β†’ antihistamines), Ataxia (PSP β†’ ventilation), Reversal of hot/cold (ciguatera β†’ mannitol).
☣️ 763 · Terrorism Agents
πŸ” SCREENING / ASSESSMENT
β€’ Nerve agents: cholinergic crisis (miosis, bronchorrhea, seizures).
β€’ Anthrax (inhalational): widened mediastinum on CXR.
β€’ Botulism: descending flaccid paralysis, no fever.
β€’ Smallpox: synchronous centrifugal rash.
β€’ Cyanide: tachypnea, seizures, lactic acidosis.
🩺 DIAGNOSTIC TESTS
β€’ Nerve agents: RBC cholinesterase.
β€’ Anthrax: blood culture, PCR, CXR.
β€’ Botulism: mouse bioassay, EMG.
β€’ Cyanide: elevated lactate, cyanide level, mixed venous oxygen saturation.
πŸ’Š MOST ACCURATE TREATMENT
β€’ Nerve agents: atropine 0.05-0.1 mg/kg + pralidoxime 25-50 mg/kg + midazolam.
β€’ Cyanide: hydroxocobalamin 70 mg/kg IV.
β€’ Inhalational anthrax: ciprofloxacin + clindamycin/rifampin.
β€’ Botulism: heptavalent antitoxin (HBAT) + respiratory support.
β€’ Smallpox: tecovirimat (TPOXX).
β€’ Decontamination first for chemical agents (remove clothes, wash skin).
πŸ“Œ MNEMONIC β€œTERROR”
Triage + Decontamination β€’ Epinephrine/atropine (nerve agent) β€’ Respiratory support (botulism, cyanide) β€’ Raxibacumab (anthrax) β€’ Oral tecovirimat (smallpox) β€’ Report immediately.

⚑ Key Screening & Treatment Mnemonics – Environmental Health

Lead BLL 3.5 β†’ succimer (45-69) // BAL+EDTA (β‰₯70)
Arsenic Mees lines β†’ BAL+succimer
Mercury Acrodynia (remove source); methylHg β†’ NO BAL
Nerve agent Atropine + pralidoxime + midazolam
Cyanide Hydroxocobalamin 70 mg/kg
Anthrax Ciprofloxacin + clindamycin
Ciguatera Mannitol IV
Amatoxin Silibinin + NAC
🌟 Critical Takeaways
β€’ Environmental history (Table 759.3) is the most important diagnostic tool.
β€’ Lead: reference BLL 3.5 ΞΌg/dL; chelation only if BLL β‰₯45 (succimer).
β€’ Arsenic: Mees lines, rice/well water β†’ BAL then succimer.
β€’ Mercury: acrodynia (pink disease) β†’ remove source, NO chelation.
β€’ Nerve agents: atropine FIRST, then pralidoxime + benzodiazepine.
β€’ Cyanide: hydroxocobalamin (turns urine red, safe).
β€’ Botulism: antitoxin + respiratory support.
β€’ Smallpox: tecovirimat + airborne isolation.
β€’ Always decontaminate before antidotes for chemical agents.