In vitro study of ingested coins: leave them or retrieve them?

Background: Objects and notably coins are frequently swallowed by children 3 to 5 years old. Precisely how they should be managed after passing the gastroesophageal junction without causing symptoms remains controversial. This study was performed to assess dissolution of specific metals from coins immersed in simulated gastric juice.

Methods: Four types of euro and US coins were immersed in simulated gastric juice for 4, 24, 72, and 120 hours. Six metals were evaluated by inductively coupled plasma-atomic emission spectrometry. Weight loss and corrosive behavior were also determined.

Results: After only 4 hours, metals had dissolved from euro (Cu, 2.86-7.85 mg; Ni, 0.23-0.52 mg; Zn, 0.09-0.99 mg; Al, 0.24 mg; Sn, 0.02 mg) and US (Cu, 1.45-6.65 mg; Ni, 0-0.62 mg; Zn, 0-0.14 mg) coins. Their concentrations in simulated gastric juice peaked after 24 to 72 hours (milligrams/hours) in euro (Cu, 218/48; Ni, 82.50/72; Zn, 83.00/72; Al, 14.65/72; Sn, 0.66/72) and US (Cu, 126.50/24; Ni, 88.00/72; Zn, 149.00/24) coins. All coins underwent corrosion and weight loss (by 2.56%-4.8%).

Conclusions: Coins retained in the stomach will release a number of heavy metals well known to cause dose-dependent poisoning. Studies to evaluate their toxicity and absorption are needed to optimize treatment.