The Case of the Dental Hygienist Who Couldn't Stop Crying

A 48 year-old Asian female came in to the office with onset of severe depression 8 months prior. Her depression was resistant to a variety of prescription antidepressants prescribed by her primary care APN and alternative approaches that included amino acid therapy to upregulate dopamine and serotonin, SAMe, and botanicals including St. Johns Wort and Riodiola rosea, methylated B vitamins, and fish oil all prescribed by her naturopathic physician.

Her medical history included dysthymia (low-level depression) for the last 10 years which she treated successfully with exercise and memory loss which she reported was accelerating in the last 2 years. She was not remembering dates she had made with friends and recently forgetting her husband’s birthday and frequently having to go back into patient’s charts to remember their names and relevant histories.

She was a career dental hygienist, and was very proud of the fact that she had chosen to have her two mercury fillings removed when she was in her late 20s and since ager 31 had also chosen to work in dental practices that did not place amalgams and only removed them. 

She reported that in the last several months she noticed she was dropping things at work and at home that were otherwise easy to grasp: dental instruments, dishes,  and other small objects.

She followed a strict gluten-free, dairy-free Paleo diet that consisted of organic meat, veggies, fruit, nuts and seeds but no grains and exercised daily: lifting weights, and bike touring across the country with her husband of 18 years, with whom she reported a very active and happy marriage. 

She had been on bioidentical progesterone (50 mg hs) since the age of 45 for irregular menses and premenstrual symptoms related to mood changes and felt that her symptoms were well controlled prior to menses and her menses were regulated.

She submitted a 24 hr urinary Toxic Metals Panel and followed that with a provocation test using oral DMPS 300 mg. on waking- collecting a 6 hour sample immediately following.

The baseline, nonprovoked results for most metals was low, either non-detectable or within the 50^thpercentile for all metals, her urine lead was .52 mcg/gm creatinine, and her blood lead levels were 1.02 mcg/dL, well below the level of concern of 2.0 mcg/dL for adults. Her post-provocation levels for lead were only 11.0 mcg/dL, not surprising as DMPS does not have a high binding capacity for lead, but since blood lead reflects body burden as well as current exposure, lead was determined not to be an issue.

Her unprovoked urine mercury was 2.6 mcg/gm creatinine- above the median value for those without amalgams. Her post-provocation levels (DMPS oral 300 mg.) were 20.7 mcg/gm creatinine and her whole blood mercury was 4.8 mcg/L, a value close to the recommended EPA safe level of blood mercury (<5.0 mcg/L). When speciated, her blood mercury contained: 4.65 mcg/L of methymercury and .15 mcg/L of inorganic mercury. 

She reported eating wild Alaskan salmon once or twice every 2 weeks, an intake that is not associated with a blood mercury of 4.65 mcg/L (average mercury levels of wild Alaskan salmon are too low to lead to that high a blood mercury level).

So where was the mercury coming from and why were her blood levels so high?

Much of the research in dental workers comes from studies by Diana Echevaria and colleagues PMID: 9707169), who have studied a large cohort of dentists and dental workers and found significant deficits in mood, memory, motor function, and visuospatial cognitive skills related to occupational mercury exposure. These problems occurred at low levels of both urine and blood mercury (pre-chelation levels of 0- 4 mcg/l urine) and post-chelation mercury (DMPS 300 mg. po) yielding 1 – 32 mcg Hg/l urine. The authors review previous studies showing the four basic effects of mercury toxicity that manifested in other occupational mercury exposure cohorts with urinary levels of mercury starting at 2 mcg/l : 

1.  systemic toxicity: salivation, insomnia, loss of appetite, sweating and blushing   
2.  emotional liability: mood swings, irritability, fatigue, apathy, withdrawal
3.  motor effects in the arms, progressing to uncoordination, imbalance, and cerebellar ataxia, tremor in muscles that are highly enervated and perform fine motor control of extremities such as fingers, eyelids, and lips)
4. loss of mental capacity progressively affecting memory, logical reasoning, or intelligence

David Warkwick DDS recently published new research looking at occupational exposure to dental workers in offices that do not place amalgam fillings but do remove them. He measured the mercury that off-gassed from the drill bit of a biologic dentistry office and found that “a dentist who removes four amalgam fillings per day will inhale 38 mg of mercury derived from amalgam particulate, by far exceeding any level considered safe.”  PMID: 31346345

This is an example of the potential for occupational risk in dental offices that remove amalgams even if they use the IAOMT SMART protocol for amalgam removal. (https://iaomt.org/resources/safe-removal-amalgam-fillings/).

Now, where did the methylmercury come from? 

Most strains of staphylococci, streptococci, yeasts and E. coli isolated from human feces, can synthesize methylmercury compounds. Methanoarchaea isolated from the human gut specifically have the ability to methylate mercury and Desulfovibrio desulfuricans ND132 and Geobacter sulfurreducens PCA can methylate mercury as well. Although these are not predominant members of the microbiome, overgrowth could potentially worsen mercury methylation. PMIDs: 1100426/26626101/23393089

Treatment

1. The patient was asked to educate her staff about the need for a high quality air filtration system in the dental office and the immediate need for mobile air filtration devices. The office installed several GC Multigas IQ air filters and eventually installed a high quality HVAC air filter. They also consulted an industrial hygienist who gave them a protocol for cleaning the mercury amalgam off of the drill bits after use. 

2.  She was started on: 
-Liposomal glutathione:  480 mg. twice a day between meals
-NAC: 1800 mg a day with meals
-R-lipoic acid: 300 mg BID with meals
-Selenomethionine: 200 mcg day with meals
-Zinc bisglycinate: 30 mg day between meals except for days on DMPS. Stop zinc 24 hrs before dosing DMPS and start 24 hrs. after DMPS
-L-ascorbate: 3 grams twice daily
-Coffee enemas twice weekly (see https://www.drjillhealth.com/product/coffee-enema-kit-only/ for an easy to administer solution and applicator)
-Curcumin: (Indena phosphytidylcholine-complexed Meriva brand) 2 capsule twice daily
-Saccromyces boullardii: 2 capsules daily to assist in normalizing microbiome
-Inulin as chicory root coffee daily for prebiotic support
-MVM supplement due to the fact that mercury exposure depletes vits. C, E, and B1.

She was asked to participate in sauna therapy daily at the clinic but chose to do that outside of the office at her gym. She was willing to do sauna 4 days a week there after work for 30 min. followed by a thorough lipid-containing soap (Dr. Bronners castile liquid soap) shower and ending with cold water on the spine.

3. After 4 weeks on the above protocol she was prescribed compounded DMPS.
Sig: 200 mg twice daily between meals once a week.

Follow-up 1 month after beginning the DMPS: she was sleeping through the night and her fatigue was significantly better.  She noticed an immediate improvement in her mood after the first dose of DMPS (used for provocation testing) and continued improvement during the first month of DMPS. She no longer found herself crying uncontrollably and was even able to laugh and joke with her colleagues at work. She found that when she was feeling poorly, a coffee enema plus a sauna would restore her energy and mood.  She was asked to continue the DMPS for another 60 days and return to the office.

Follow-up 6 months later found that her blood mercury was 2.6 mcg/L (90^th percentile for NHANES CDC database) and her urine mercury had declined to 1.2 mcg/gm creatinine (equivalent to the 95^th percentile of the NHANES CDC database.)  (https://www.cdc.gov/exposurereport/data_tables.html)

Obviously, these levels are still elevated based on the national average. But clearly this case shows that a basic protocol to increase urinary excretion via chelation and biliary excretion as well as ancillary support are sufficient to deal with the debilitating effects of chronic occupational mercury exposure.