Mercury Exposure According to the Czech Toxicological Information Centre (TIC) from 1995 to 2007

Objective: Thermometers filled with mercury are commonly used in the Czech Republic. The objective is to describe the development and course of mercury exposure, and the frequency, based on calls to the TIC with a country-wide population of approximately 10 million. Methods: Data on mercury exposure in years 1995 to 2007 (till 12.11.2007) was taken from the Czech Toxicological Information Centre (TIC) database. Results: Between 1995 and 2007 TIC responded to 1201 inquiries following mercury exposure resulting in 1.18 % of total calls to TIC. The average number of calls per year did not fall below 1% (median 1.13%). Most cases dealt with oral intake. In 63.1% of total cases metallic mercury was involved: 97% ingested e.g. in tea which was stirred by a mercury thermometer, 2% per rectum (broken mercury thermometer) and 1% intravenous, paravenous or intramuscular (self-administration). 7.2% of total cases were people endangered by mercury vapours. In 1.6% soluble mercury salt was identified and in 28.1% only suspicion of ingestion by children occurred. In 81 cases (from 4 to 13 cases per year) a suicidal attempt was registered. From 132 calls obtained during the last 12 months the most severe case concerned an 83 year old man with pre-existing cardiovascular disease who ingested 1 g of mercury chloride in a suicide attempt. He was admitted to the ICU due to a sudden loss of consciousness and convulsions however he recovered en-route. On admission he was awake with vital signs: BP 118/70 mmHg, HR 70/min. Gastric lavage was performed, one dose of the antidote DMPS was given intravenously and hemodialysis due to acute renal failure was performed 3 times. Mercury plasma level of 4.96 mg/L confirmed the high dose ingested. Moreover he experienced haemorrhagic enterocolitis and as a complication bronchopneumonia. He was discharged on the 15th day with borderline renal parameters. Conclusions: In the overwhelming majority of calls the prognosis was good, due to low oral absorption and negligible inhalational exposure of metallic mercury. However, the vast majority of accidents could be prevented and healthcare service saved by replacing mercury in thermometers by a less toxic filling.