Mercury

Synonyms

Quicksilver; [NIOSH] Mercury, elemental

Category

Elements, Metallic

Description

Metal: Silver-white, heavy, odorless liquid. [NIOSH]

Sources/Uses

MINING, SMELTING, OR METALLURGY: Cinnabar ore mining and crushing operations; gold extraction (cyanide leaching or amalgamation processes);\ MANUFACTURING: Thermometers, manometers & barometers; dental amalgam; polyurethane catalyst; switches & rectifiers; dry cell batteries; paints;\ USING OR DISPOSING: Open mercury cells in chloralkali plant for maintenance; use mercury amalgams in dental office; In gold extraction, mercury exposure occurs during the amalgamation stage and especially during the release of gold by heating. [Nordberg, 834]

Comments

Elemental liquid mercury is poorly absorbed from the GI tract, and it is considered nontoxic by ingestion in patients with normal GI anatomy and motility. Elemental mercury vapor is toxic predominantly to the lung and central nervous system. Pneumonitis can result from exposure to high concentrations of heated mercury vapor in a confined space. Otherwise, inhalation of mercury vapor is toxic over a period of months or years when air levels exceed 0.05-0.2 mg/m3. The main adverse effects after chronic exposure to mercury vapor are neuropsychiatric and include tremor, memory loss, insomnia, anorexia, irritability, and other mood changes. Kidney disease and peripheral neuropathy have been rarely reported after chronic exposure to mercury vapor. Acrodynia is a rare idiosyncratic disorder reported in children after mercury vapor exposure. [Olson, p. 305-7] Data is limited on the fetal effects of mercury in forms other than methyl mercury. Experimental animals exposed to high doses of mercury vapor and salts have increased developmental abnormalities. [ATSDR Case Studies #29] Mercury may produce slight hepatic injury in experimental animals. [Zimmerman, p. 419] Background levels of mercury are generally <10 ug/L for whole blood and <20 ug/L for urine. Regarding dental amalgams as a source of mercury vapor, occupational exposures can be controlled and personal exposures from fillings are insignificant. [Goldfrank, p. 1302, 1304] "Exposure to metallic mercury, for example from amalgam teeth fillings and other dental exposure, may give rise to sensitization." [Nordberg, p. 1041] See "Mercury, inorganic compounds."

Reference Link #1

Biomedical References

Mercury in urine = 20 ug/g creatinine; sample prior to shift; Indicate average exposure during the past month; BEI for blood mercury withdrawn: may reflect recent exposure, but also affected by dietary exposure to methyl mercury in fish; [TLVs and BEIs]

Yes

Yes

0.025 mg/m3, as Hg

0.1 mg/m3, as Hg

0.02 mg/m3, as Hg, inhalable fraction

10 mg/m3, as Hg

Excerpts from Documentation for IDLHs

A single 4 hr. dose of 28.8 mg/m3 of mercury vapor caused severe damage to the kidneys, lungs and colon of rabbits, while a one hr. exposure caused mild injury.

0.002 mm Hg

LCLo (rabbits) = 29 mg/m3/30 hr

Explanatory Notes

"Animal studies indicate that elemental mercury as a liquid or vapor can be absorbed percutaneously." Organic mercury is readily absorbed through skin. [ATSDR Case Studies] Boiling point = 674 degrees F. [NIOSH] VP = 0.002 @ 25 deg C; [HSDB]

Metallic and inorganic in whole body: 1-2 months; blood: 2 days to 1 month; methylmercury in blood: 1 month; methylmercury in whole body: 44-79 days; [TDR, p. 813]

Reference Link #2

Not appropriate

0.25 ppm

0.5 ppm

Yes

Yes

Sensorimotor

Yes

Yes

Not classifiable

Not Classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Chronic renal failure
• Contact dermatitis, allergic
• Mercury, elemental, chronic toxic effect
• Neuropathy, toxic
• Pneumonitis, toxic

Processes

Industrial Processes with risk of exposure:

• Abrasive Blasting
• Battery Manufacturing
• Metal Extraction and Refining
• Mining
• Photographic Processing
• Using Disinfectants or Biocides
• Welding Over Coatings

Activities

Activities with risk of exposure:

• Ingesting herbal remedies
• Painting