Arsenic in a Child's World

Authors and Disclosures

Ann Pike-Paris, BS, MS, is a consultant, East Aurora, NY

Sidebar: Hot Box - Arsenic

Sources. Organic arsenic, which typically combines with carbon or hydrogen and is considered less harmful than inorganic compounds, is found in seafood (cod, haddock) and shellfish (mussels, lobster, etc.); pesticides (methylated) in pentavalent compounds; and used as herbicides on cotton, citrus, and sod (ATSDR, 2001).

Absorption. Pentavalents are water-soluble and absorbed by mucous membranes. Oral ingestion is the typical route. Dermal absorption is poor.

Clinical effects. Ingestion of organic arsenic via seafood is not believed toxic and should have no effect upon children (AAP, 2003). Organic compounds are absorbed by the gastrointestinal tract and cause toxic injuries to the central nervous system (CNS) and virtually all organs. In acute poisoning, symptoms appear within an hour: garlic breath, vomiting, abdominal pain, bloody diarrhea, headache, dizziness, drowsiness, cardiac arrhythmia. Liver and renal damage and death occur within 1-3 days (EPA, 1999). In chronic exposure there is generalized fatigue; peripheral and CNS effects such as sensory changes, paresthesia, muscle tenderness, complaints of pain in the feet, liver injury, anorexia; and skin changes such as hyperkeratosis on palms and soles, hyperpigmentation in non-sun exposed areas (Children's Environmental Health Network [CEHN] 1999), melanosis, eczema like eruptions, and Mees lines on the fingernails (AAP, 2003).

Diagnosis. Due to arsenic's excretion in the urine, in both acute and chronic exposure, diagnosis is made with an 8-24 hour urine collection. It is important to remember that ingestion of seafood prior to testing may raise urine levels for 2-5 days. Blood is not an accurate test due to the short half-life of arsenic. Hair samples in chronic exposure have not been widely accepted as a diagnostic tool (EPA, 1999).

Treatment. Both acute and chronic exposure is treated with chelation with dimercaprol (BAL), DMSA (succimer), d-penicillamine DMPS (CEHN, 1999; AAP, 2003).

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Arsenic-As

Sources. Inorganic arsenic is found in ground and surface water; hazardous waste sites, smelting facilities, incinerators, mines, and agricultural facilities, which leach arsenic into the air, water, and soil; wood treated with CCA; pesticides as used in utility poles; batteries; solar cells; feed additives for poultry and swine; treatment of acute promyelocytic leukemia (APL); and alternative medicines from China and India (Espinoza, Mann, & Bleasdell, 1995).

Absorption. Ingestion via the GI tract is the most common route in children. Inorganic arsenic may also be inhaled as the gas form, arsine, which is extremely toxic, or as ambient air. Arsenic has a half-life of 10 hours and is detoxified in the body by conversion to the organic species and excreted in the urine. Children appear less able to detoxify arsenic and, consequently, have slower rates of clearing it from the body. It is when these rates of detoxification are outpaced by exposure that toxicity occurs (CEHN, 1999; AAP, 2003).

Clinical effects. Acute symptoms are identical to organic. Chronic exposure is also identical; however, skin changes serve as an important clue. Symptoms may not appear for at least 5 years and other issues such as genetics, age, metabolism, diet, and overall health may have an impact on the onset as well (Physicians for Social Responsibility [PSR], 2001). Arsenic is classified as a known human carcinogen.

Diagnosis. Inorganic exposure is diagnosed in the same manner as for organic, an 8-24 hour urine collection. Spot urine has not been validated as a reliable test for children (Committee for Environmental Health, 2003).

Treatment. If significant exposure has been clinically shown, chelation therapy with BAL, DSMA, or DMPS is used. Arsine (gas) exposure would mandate supportive care (oxygen and maybe blood transfusions) and heavy fluid intake to dilute and aid in excretion of arsenic (CEHN, 1999; EPA, 1999).