Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair

Abstract Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3 g of hexavalent Cr (Cr VI ), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically Cr VI reactive intermediates and reactive oxygen species. After Cr VI has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of Cr VI to Cr III reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of Cr VI is cleared in urine as Cr III . We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30 g/L potassium dichromate (the estimated amount of ingested Cr is about 3 g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7 days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49 days. During this period Cr decreased respectively from 2088 μg/L to 5 μg/L, 631 μg/L to 129 μg/L and 3512 μg/g to 10 μg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2 months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.