Title: Pediatric lead exposure and poisoning (e.g. Flint, MI)<br/>Author: Hong Kim<br/><a href='http://umem.org/profiles/faculty/526/'>[Click to email author]</a><hr/><p>
        Lead is a ubiquitous metal in the environment partly due to decades of using leaded gasoline (organic lead) and lead-based paint (inorganic lead). Outside of occupational exposure, children are disproportionately affected from environmental lead exposure.</p>
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         </p>
<p>
        Common route of exposure are:</p>
<ol>
        <li>
                Ingestion (common in children): soil, water, lead-based paint chips, toys, certain folk remedies.
                <ul>
                        <li>
                                Absorption: adult: 3 – 10% vs. children: 40 – 50%</li>
                </ul>
        </li>
        <li>
                Inhalation (mostly occupational exposure): lead dust
                <ul>
                        <li>
                                Absorption: 30 – 40%</li>
                </ul>
        </li>
        <li>
                Dermal (minor): cosmetic products
                <ul>
                        <li>
                                Absorption: < 1%</li>
                </ul>
        </li>
</ol>
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         </p>
<p>
        Majority of the absorbed lead are stored in bone (years) > soft tissue (months) > blood (30-40 days) (half-life). Thus blood lead level does not accurately reflect the true body lead burden.</p>
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         </p>
<p>
        Incidence of elevated blood lead level (EBLL <u>></u> 5 microgram/dL) in children increased from 2.9 to 4.9% in Flint, MI before and after water source change. In the area with the highest water lead level, the incidence increased by 6.6%.</p>
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         </p>
<p>
        Clinical manifestation in children</p>
<table border="1" cellpadding="0" cellspacing="0">
        <tbody>
                <tr>
                        <td style="width:295px;">
                                <p>
                                        Clinical severity</p>
                        </td>
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                                <p>
                                        Typical blood lead level (microgm/dL)</p>
                        </td>
                </tr>
                <tr>
                        <td style="width:295px;">
                                <p>
                                        <strong>Severe</strong></p>
                                <ul>
                                        <li>
                                                CNS: encephalopathy (coma, seizure, altered sensorium, ataxia, apathy, incoordination, loss of developmental skills, cranial nerve palsy, signs of increased ICP</li>
                                </ul>
                                <ul>
                                        <li>
                                                GI: persistent vomiting</li>
                                </ul>
                                <ul>
                                        <li>
                                                Heme: anemia</li>
                                </ul>
                        </td>
                        <td style="width:295px;">
                                <p style="text-align: center;">
                                        > 70 – 100</p>
                        </td>
                </tr>
                <tr>
                        <td style="width:295px;">
                                <p>
                                        <strong>Mild to moderate</strong></p>
                                <ul>
                                        <li>
                                                CNS: hyperirritable behavior, intermittent lethargy, decrease interest in play, “difficult” child</li>
                                </ul>
                                <ul>
                                        <li>
                                                GI: intermittent vomiting, abdominal pain, anorexia</li>
                                </ul>
                        </td>
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                                <p style="text-align: center;">
                                        50 – 70</p>
                        </td>
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                                <p>
                                        <strong>Asymptomatic</strong></p>
                                <ul>
                                        <li>
                                                CNS: impaired cognition, behavior, balance, fine-motor coordination</li>
                                </ul>
                                <ul>
                                        <li>
                                                Misc: impaired hearing or growth</li>
                                </ul>
                        </td>
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                                <p style="text-align: center;">
                                        > 10</p>
                        </td>
                </tr>
        </tbody>
</table>
<p>
         </p>
<p>
        Evaluation for lead poisoning</p>
<ol>
        <li>
                Blood lead level (BLL)</li>
        <li>
                CBC: hypochromic microcytic anemia, basophilic stippling</li>
        <li>
                Imaging: abdominal XR – check for foreign bodies in GI tract; long-bone XR – lead lines</li>
</ol>
<p>
         </p>
<p>
        Management of children with EBLL</p>
<ol>
        <li>
                Removal from exposure</li>
        <li>
                Environmental investigation/intervention (BLL: 15 - 44 ug/dL)</li>
        <li>
                Chelation
                <ul>
                        <li>
                                Asymptomatic (BLL: 45 – 69 ug/dL): Succimer (PO)</li>
                        <li>
                                Symptomatic (BLL: > 70 ug/dL): Dimercaprol (IM) and CaNa₂EDTA (IV)</li>
                </ul>
        </li>
</ol>
<fieldset><legend>References</legend>

                <ol>
        <li>
                Dapul H, Laraque D. Lead poisoning in children. Advances in pediatrics 2014;61:313-333.</li>
        <li>
                Hanna-Attisah M. et al. Elevated blood lead levels in children associated with the Flint drinking water crisis: a spatial analysis of risk and public health response. AM J Public Health 2016;106:283-290.</li>
        <li>
                Goldfrank's Toxicologic Emergencies 10th ed.</li>
</ol>
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         </p>
</fieldset>