Hi Helen,
Not knowing is not being stupid.
In my case, I am very toxic with Methylmercury (MM). I was stationed in the Far East and ate tons of raw fish and continued to do so when I returned stateside. My claim is by exclusion of other Mercury sources, although I have read that the human body can convert Elemental Mercury (EM) (Dental Amalgam) in to MM. However, my heavy fish consumption, mostly tuna, lends itself to my test-confirmed MM poisoning. I consumed raw tuna roughly from 1994-present. The body's MM excretion method is via hair.
I am also test-confirmed toxic with Elemental Mercury from Dental Amalgam, again by exclusion. Its excretion method is via the toilet, both inputs.
My first symptom was, since 2013, unending head and ear ringing. Again, by exclusion. I stopped working in a hazardous noise environment in 2013, and I am fervent in protecting my hearing. I was exposed to hazardous noise in the USAF for 15 years daily, and periodically for another 13. Add five more years as a contractor.
My poisoning is SO bad (how bad is it..?), that it is in my skin oil, blood, and saliva.
While searching for an accurate test, I acquired a USB microscope and have microscopic pictures of the Mercury in my skin oil. I have lost tricep, bicep, pectoral, shoulder, and calf muscles. The atrophy is caused by compromised communication between the brain and muscles, akin to Amyotrophic Lateral Sclerosis, or Lou Gherig disease (ALS.org).
To your question, the human body has NO use for Mercury. It is causal in brain disorders like Alzheimer's, Parkinson's, Dementia, and more. The test that I used is called a "Tri-Test" from Quicksilver Scientific (QS) that tests hair (excretion), urine (excretion), and blood (two tests) that differentiate between MM and EM. The site recommends ordering the test through a Functional (Holistic) Medicine provider. Mine marked the kit up by $100. The reason QS wants patients to use a provider is to interpret the test results. My total test cost was $400. For me, testing was IMPERATIVE.
I interpreted my test results before I saw the provider. It is not rocket science, just graphs, but QS' test interpretation instructions are important.
I hope that I answered your questions. Getting tested is an individual choice and I am happy to share my results with you, conditional on not sharing my information. I already redacted a copy, but please do not share my posted picture. Feel free to private message me if you need more information. I have researched Mercury toxicity for the past 3+ years while searching for a good test. Much more to this public health issue than the CDC and FDA will publicly admit. Try https://amalgam.com for more info. Dr. Leo Cashman has been at this for far longer that I, though I will take the fight to another level, maybe via a PhD dissertation. Hit this too, very credible information: (https://orawellness.com/how-to-safely-remove-mercury/).
Take Care,
--> Rick