Mercury Quiz

In 1971, seeds that were originally imported for agriculture were diverted to the domestic market and incorporated into consumer products. These seeds were treated with methylmercury as an antifungal agent and were likely never originally intended for consumption. As a result, over 400 people died and numerous more were hospitalized. Imported seafood could be implicated in methylmercury poisoning, but it is not the case here. The seeds were originally intended for agriculture and not for consumption, so answer 3 is incorrect. Methylmercury is not associated with blackmarket spirit distillates; nor is it associated with imported cooking oils.

In this case, the most likely explanation for the patient’s symptoms is acute elemental mercury pneumonitis, which can occur after inhalation of vaporized mercury fumes. This is associated with metal workers and jewelers. All of the other answers are incorrect.

Exposures to elemental mercury tend to accumulate in the kidney, and as per Goldfrank’s, especially within the renal tubule. There, metallothionein binds and detoxifies mercurial ions. All of the other answers are incorrect.

Basically, long chain organomercurial compounds are more quickly metabolized to form organic mercury cations and corresponding acid. This results in a more rapid detoxification of the molecule. However, short chain orgranomercurial compounds are not easily metabolized and cross the blood brain barrier leading to delayed toxicity.

The majority of organomercurial compounds (90%) are excreted through the biliary/fecal route. There is minimal renal excretion, which contrasts to elementary mercury which seems to be predominantly renally excreted. The other answers are incorrect.

The only correct answer is that mercurial compounds covalently bond to numerous sulfhydryl groups, thereby exerting toxicity. None of the other answers are correct.

Out of all the listed possibilities, the most likely exposure for a Mercury exposure is an Ayurvedic prescription. They can contain either elemental or organic mercury depending on the formulation. Indications for the prescription or intended effects are not covered in this question. Please feel free to google at your pleasure.

Of the answers above, only central intention tremor that is abolished with sleep is strongly suggestive of mercury poisoning. The etiology of this phenomenon is unclear. Echolalia is a psychiatric condition in which the patient repeats words that are said; it is not associated with inorganic mercury poisoning. Mercury poisoning is not associated with alcohol abuse. Recurrent motor tics are also not associated with inorganic mercury exposure. Delusions of parasitosis are commonly seen with sympathomimetic abuse (bugs crawling on skin).

Of the answers above, only central intention tremor that is abolished with sleep is strongly suggestive of mercury poisoning. The etiology of this phenomenon is unclear. Echolalia is a psychiatric condition in which the patient repeats words that are said; it is not associated with inorganic mercury poisoning. Mercury poisoning is not associated with alcohol abuse. Recurrent motor tics are also not associated with inorganic mercury exposure. Delusions of parasitosis are commonly seen with sympathomimetic abuse (bugs crawling on skin).

Out of all of the above listed possible answer choices, only the organic mercury compound could be responsible for the devastating effects observed in Minamata disease. An industrial company’s waste water run-off dumped into several bays and the association between the disease syndrome of the victims, who were fisherman and family, was later identified by epidemiological studies.

Group B will likely have less birth defects because they eat fish on the lower end of the food chain. Fish on the lower end of the food chain bioaccumulate less toxins, and in this case likely methylmercury. Methylmercury is difficult, if not impossible, for most animals to remove from their body. Therefore, the more they eat, they more they accumulate. The larger the fish, the higher in the food chain and the more likely they are to have higher concentrations of methylmercury. Methylmercury has been associated with birth-defects. Please take in mind that this analysis is based on FDA recommendations and data is actually conflicting.

The best test to identify acute organic Mercury toxicity is whole blood. All of the other answers are incorrect. They may show positive levels, but it will be difficult to correlate. If you suspect it, order the right test.

This patient has acute pulmonary toxicity likely due to aerosolized Mercury. The patient needs supportive care and chelation therapy. In this case, the only appropriate answer is dimercaprol IM. Were this case to continue into a subsequent question, the recommendation would likely be early consult with an ECMO team because the patient has fulminant pulmonitis. Pulmonary diffusing capacity will likely continue to deteriorate, which could lead to death. However, temporary placement on a V-V ECMO circuit would likely benefit this patient because his respiratory failure will likely resolve.

In this case, the patient has a confirmed exposure to an organomercurial compound. This is high risk for delayed neuropsychiatric sequelae; nonetheless, this is not an emergency. The patient should be counseled on the serious repercussions that could develop in the ensuing months. Yet, there is little to do in the ER other than start chelation therapy. Succimer is the safest and most efficacious option for this patient. OF NOTE: Succimer is quite expensive and limited in supply so social work should be consulted to help facilitate procurement of this medication. Admission is not warranted because effects will be delayed for months. Simply obtaining basic labs without treatment is inappropriate because the patient has a viable treatment option, even though evidence for this treatment may be lacking due to testability of the patient’s rare condition. The patient then should be referred to a toxicology department that specializes in out-patient care of poisoned patients. If this is not available, care should be coordinated with an occupational health specialist who will be in consult with a medical toxicologist either through a local institution or the regional poison control center.