Lead Toxicity From Imported Jewelry

Abstract

We summarize here the presentation and course of lead poisoning in a 1-year-old who ingested a lead-containing metallic medallion from India. We analyzed the medallion to determine its composition, using x-ray fluorescence spectroscopy and field emission scanning electron microscopy. A simple extraction test was used to estimate oral bioavailability. We used the US Environmental Protection Agency Integrated Exposure Uptake Biokinetic model to compare actual versus predicted blood lead levels. X-ray fluorescence analysis revealed the composition of the medallion to be: Lead 155 000 ppm (15%), copper 530 000 ppm (53%), nickel 49 000 ppm (4.9%), arsenic 22 000 ppm (2.2%), antimony 12 000 ppm (1.2%), tin 3000 ppm (0.3%), and silver 1300 ppm (0.13%). With a fixed ingestion of 7786 µg/d (estimated by simulated gastric extraction analysis) and assuming 50% bioavailability, Integrated Exposure Uptake Biokinetic modeling predicted the geometric mean blood lead level would increase from 2.05 µg/dL to 173.9 µg/dL. This patient had potentially life-threatening lead poisoning from an ingested piece of jewelry. The medallion contained 550 times the allowable content of lead in children’s metallic jewelry sold in the United States. This case highlights the ubiquitous nature of lead in our global environment and the risk of exposure to novel sources, especially for children.

Even at low levels of exposure, lead acts as a neurotoxin to the developing brain. On a population level, scientific studies have not been able to identify a safe threshold of lead exposure that is not associated with adverse cognitive, behavioral, and other effects in infants and children.^1–6 Yet, children continue to be exposed to lead hazards in their homes because of lead-containing paint, lead in drinking water, and other sources of exposure. There have been only a handful of clinical cases of lead poisoning resulting from ingestion of children’s jewelry and charms, with varying severity from higher blood lead levels (BLLs) without symptoms to fatal encephalopathy.^7–9 We report here childhood lead poisoning from the ingestion of a metallic medallion originally purchased in India. We conducted a detailed study of the medallion’s composition, its bioaccessibility, and its estimated contribution to this child’s BLL.

Clinical Case Presentation

A 1-year-old male of Indian descent was identified on routine lead screening by his primary care physician to have venous BLL of 97 µg/dL and referred to our emergency department in April 2015. Further laboratory testing revealed a microcytic anemia with hemoglobin of 9.5 µg/dL, mean corpuscular volume 68.2 fL in the setting of normal iron studies. Abdominal radiographs revealed an irregularly shaped radiopaque foreign body in the pylorus (Fig 1). The patient was emergently taken to the operating room for endoscopic extraction of the foreign body, a 1.8 cm × 2.1 cm × 0.4 cm metal medallion (Figs 2 and 3). At endoscopy, the stomach lining had a noticeable sheen. The family identified the recovered object as his 4-year-old sister's jewelry pendant, depicting a Hindu deity, that was purchased in Northern India. Apparently, his sister had fed the medallion to the patient weeks earlier.

FIGURE 1.

Abdominal radiograph of an irregularly shaped radiopaque foreign body in the pylorus.

FIGURE 2.

Jewelry medallion ingested by 1-year-old child and location at endoscopy.

FIGURE 3.

Backscattered scanning electron microscopy images of metallic medallion showing the heterogeneity of topography and variations in chemical composition across the medallion surface. The images show that various coatings have been partially dissolved by gastric fluids. The brighter areas of the images likely contain higher levels of lead. Images courtesy of Todd Hinkley, Heather Lowers, and Geoff Plumlee (US Geological Survey).

On further history, the family recounted that, over the past 1 to 2 months, the patient was repeatedly having nonbilious emesis after most meals with associated weight loss. After endoscopic extraction of the ingested foreign body (Fig 2), the patient was admitted to our medical ICU and started on parenteral chelation therapy with dimercaprol and edetate calcium-disodium. He subsequently required outpatient management with serial cycles of oral chelation therapy with dimercapto succinic acid and D-penicillamine. He had persistently high BLLs to 28 µg/dL 1-year postexposure, and 16 µg/dL 3 years later.

His posthospitalization course required multidisciplinary care with gastroenterology and feeding specialists in additional to the environmental health team. His poor weight gain and repeated episodes of emesis were thought to be secondary to the sessile foreign body, creating an outlet obstructive mechanism in the gastrointestinal (GI) tract. This longstanding history of GI distress was compounded by the adverse effects of chelation therapy (nausea and vomiting), resulting in chronic feeding issues and oral aversion to food. Bioaccessibility/extraction testing of the medallion later identified the presence of copper in the medallion, posing additional health risks. Excessive copper exposure can lead to GI symptoms, hemolytic anemia, hepatitis, and neurologic dysfunction.¹⁰ The copper content of the medallion was only discovered on extraction analysis much later, after the child’s recovery. It is possible that copper toxicity contributed to our patient’s iron deficiency, as well as his GI distress. The patient’s blood copper level, obtained 2 years later, was 126 mcg/dL (upper range of normal 150 mcg/dL). However, his blood copper levels could have been much greater at time of presentation.

By the time of his last follow-up clinic visit in December 2018, >3 and a half years after presentation, the patient was beginning to tolerate a more advanced diet. He had age-appropriate development and his BLL had declined to 14 mcg/dL.

Methods

Medallion Composition Analysis

The Department of Laboratory Medicine at Boston Children’s Hospital and the US Geological Survey in Denver, Colorado, used x-ray fluorescence (XRF) spectroscopy and field emission scanning electron microscopy to determine the heavy metal makeup and other properties of the foreign body (Fig 3). The patient’s parents consented to having an analysis conducted on the ingested foreign body to determine the lead and heavy metal content.

Bioaccessibility Analysis

To assess bioaccessibility of the ingested foreign body in the low-pH environment of the stomach, we used a simple bioaccessibility extraction test.¹¹ The simple bioaccessibility extraction test is an in vitro gastric fluid extraction that simulates metal dissolution in the stomach. Briefly, the medallion was placed in 50 mL of artificial gastric juice (0.2% NaCl 0.8% HCl) with serial rotation of the sample over 7 days.

IEUBK Modeling

The bioaccessibility results were evaluated using the United States Environmental Protection Agency (EPA) Integrated Exposure Uptake Biokinetic (IEUBK) model.¹² This is a validated mathematical model based on parameters that account for uptake on the basis of magnitude of exposure source, route, and biokinetics that is used to predict BLLs in children up to 7 years of age.^13–15 We used the model to estimate a geometric mean BLL and to compare predicted BLLs in a population of children with typical background lead exposures versus a population ingesting a foreign metal object of similar composition. The model was run using a stomach content simulation of 50% absorption (median). The model parameters were set using EPA-recommended default values for all parameters except lead ingestion via water and soil. For the water ingestion parameter, we assumed 0.217 L/d on the basis of values in the EPA Child-Specific Exposure Factors Handbook (P. 3–14, mean, age 6 months–<6 years).¹⁶ We also assumed a more locally relevant soil lead concentration of 100 ppm.¹⁷

Results

Composition

Electron microscopy revealed the heterogeneous topography of the metallic medallion (Fig 3). XRF analysis of the medallion yielded the following results: Lead 155 000 ppm (15%), copper 530 000 ppm (53%), nickel 49 000 ppm (4.9%), arsenic 22 000 ppm (2.2%), antimony 12 000 ppm (1.2%), tin 3000 ppm (0.3%), and silver 1300 ppm (0.13%). Elements below the detection level: Cadmium, zinc, mercury, cobalt, molybdenum, uranium, thorium, iron, and manganese.

Bioavailability

Extraction testing of simulated gastric fluid revealed a lead content of 1.09 mg/mL in the aliquot containing the medallion with undetectable levels in the untreated control sample. This result translates to a lead dose of 7786 ug per day or 54 500 ug per week. On the basis of the IEUBK model and an assumption of 50% stomach contents and daily exposure to the lead leaching from the charm, the BLL was predicted to be 173.9 µg/dL, with a 99.9% likelihood that a BLL would be ≥24 µg/dL.

Discussion

This patient was exposed to potentially fatal levels of lead poisoning, had his high BLL and retained foreign body not been identified by routine lead testing by his primary care physician. This case highlights the ubiquitous nature of lead in our global environment and the increased risk of lead exposure to novel sources of lead for children. Such exposure also illustrates that jewelry may contain other harmful metals; it was only later in follow-up of this patient did composition testing reveal significant concentrations of copper, which, in retrospect, could have contributed to the patient’s GI complaints. Previous studies have documented the continued hazard of lead and other metals contaminating manufactured low-cost children’s toys and jewelry available in marketplaces around the world.^18–20 A 2022 Israeli study documented the persistence of metals-contaminated children’s toys in the marketplace even after tighter governmental regulations were imposed.²¹

This ingested medallion exceeded the allowable content of lead in children’s metallic jewelry as per both the US Consumer Product Safety Commission and the European Union enforcement guidelines. If a 12- to 24-month-old child ingests children’s metallic jewelry with lead content allowable by current US Consumer Product Safety Commission policy and it remained in the stomach for 30 days, his or her blood lead level after 365 days would be predicted to rise to only 4.2 µg/dL.^22–24 The European Chemical Agency has described a “derived no effect level” (DNEL) for lead content in jewelry as below 960 ug/d.²⁵ This DNEL was intended to be protective of acute health effects by ensuring that a 12- to 18-month-old child’s BLL does not exceed 40 µg/dL when jewelry stays in the stomach for up to 5 days. If a 12- to 24-month-old child ingests children’s metallic jewelry with lead content allowable by the European Union policy and it was retained in the stomach for 30 days, the BLL after 365 days would be predicted to rise to 11.6 µg/dL. For comparison, the bioaccessible lead in the charm from India that the subject child ingested was 50 times higher than the DNEL based on European regulations (ie, 54 500 µg per day).²⁶

There are limitations to this analysis. The IEUBK model conservatively estimates daily chronic exposure to sources of lead in drinking water, dust, and food, and was developed to evaluate chronic long-term exposures, not acute exposures. Hence, the EPA model will underestimate exposure during the incident. Also, environmental exposures associated with BLLs >30 µg/dL are above the range of values that have been calibrated and validated in the IEUBK model. These values should not be interpreted as precise estimates.

Conclusions

Jewelry ingestion resulted in clinically significant, severe lead poisoning in a young child. His peak BLL at 97 mcg/dL could have resulted in potentially life-threatening consequences. Expanding provider awareness of the ubiquitous nature of lead in our environment can broaden differential diagnoses in clinical settings for children with unexplained failure to thrive, vomiting, behavioral changes, and/or anemia to include the potential of foreign body with heavy metal poisoning. Further morbidity or mortality for this patient was prevented as a direct result of universal blood lead testing recommendations for this age group in Massachusetts. Early detection and intervention are key to minimizing health impacts of such exposures. Consideration of these risks can inform prevention efforts regarding restriction of lead in consumer products globally to minimize exposure-related health risks to children. This case illustrates the need for more global cooperation, with the recommendation that all countries include policies of increased surveillance and enforcement to ensure the safety of all commercial products intended for the public’s use.

Glossary

BLL

blood lead level

DNEL

derived no effect level

EPA

Environmental Protection Agency

GI

gastrointestinal

IEUBK

Integrated Exposure Uptake Biokinetic

XRF

x-ray fluorescence