What is Mercury?
Mercury is a naturally occurring metallic element (Hg) that rarely exists in its liquid state in the environment. It commonly exists within cinnabar ore as mercury (II) sulfide (an inorganic salt compound) and as impurities with other minerals. Like water, mercury can exist in three states of matter in the environment; solid, liquid, or gas. The most commonly encountered natural forms of mercury are elemental mercury, inorganic mercury, and organic methylmercury. Each form has different chemical properties, toxicity, and use. Anthropogenic emissions that carry elemental or inorganic mercury primarily originate from coal-fired power plants, the burning of municipal and medical waste, and factories that use mercury in their production process.
Mercury Types and Beneficial Uses
Elemental mercury or metallic mercury is a shiny, silver-white metal, historically referred to as quicksilver, and exists as a liquid at temperatures above -38 degrees Fahrenheit. Most elemental mercury is human-made and derived from cinnabar ore. Elemental mercury is used in older weather measuring and medical instruments, dental fillings, fluorescent light bulbs, electronic equipment, and electrical switches.
Inorganic mercury is naturally abundant in the environment and primarily bound to the mineral cinnabar and as impurities with other minerals. Mercury sulfide can readily weather to form inorganic salts dissolved by and transported in water and deposited in soil and sediment. Inorganic mercury compounds are used in photography, topical antiseptic and disinfectant, wood preservative, and fungicide. Mercuric sulfide is used to color paints and is one of the red coloring agents used in tattoo dyes.
Organic mercury compounds are formed from chemical and physical transformations of elemental and inorganic mercury in the environment. A typical chemical change involves the metabolic combination of carbon with inorganic mercury by microscopic organisms living in water and soil. Methylmercury is the most common and toxic by-product of this metabolic process and accumulates in the food chain through bioaccumulation and biomagnification. Bioaccumulation refers to the accumulation of a toxic chemical in the tissue of particular apex organisms. Biomagnification refers to the increased concentration of a toxic chemical in organisms’ tissue caused by ingesting lesser organisms. Methylmercury has no beneficial uses.
Affects of Mercury on Human Health
The three chemical forms of mercury are toxic to humans. Each exhibit different health effects depending on the concentration and duration of time the person was exposed to the particular mercury form. The most common human exposure pathways are inhalation and ingestion of shellfish and apex fish.
At room temperature, elemental mercury converts to a gas and becomes an invisible, odorless toxic vapor. Humans may be exposed when they breathe air containing elemental mercury vapors generated at their workplaces and locations where elemental mercury has been spilled or released. Human exposure to elemental mercury affects our central nervous systems (CNS) and can cause tremors, affect cognitive thinking, slowed nerve function, etc.
Human exposure to inorganic mercury salts can occur both in occupational and environmental settings. Occupations with a higher risk of exposure to inorganic mercury include mining, electrical equipment manufacturing, and chemical and metal processing in which inorganic mercury is used. Exposure to inorganic mercury usually occurs through ingestion or dermal exposure, and it can be very corrosive to the skin, eyes, gastrointestinal tract, and kidneys.
Exposure to methylmercury in small concentrations results in CNS effects such as blindness, deafness, blurred vision, etc. Fetuses and young children exposed to methylmercury can experience severe developmental impairment.
During 2012-2015, the USEPA responded to 225 mercury-release incidents; the average cost of cleanup ranged from $30,000 to $75,000 each year, and the highest cleanup cost during this period was $913,915 in 2013. Elemental mercury spills are the most common type of mercury-related pollution events and remediating them is costly and time-consuming. The remediation contractor has to locate the spilled material, which involves very expensive mercury vapor analyzers. Once the mercury source is identified, it must be physically removed with High-Efficiency Particulate Air (HEPA) vacuums specifically constructed to collect the elemental mercury. All of the porous materials in the immediate area have to be removed by demolition or physically carried from the area and disposed of as hazardous waste. The screening, removal, and demolition process is repeated until the ambient air reports a mercury vapor action level equal to or less than one (1) microgram (µg) per cubic meter (m3); however, concentrations of 1 to 3 µg/m3 are considered acceptable for schools because of the reduced duration of exposure.
How Can VERTEX Help?
VERTEX employs a team of environmental insurance professionals who can investigate the cause, origin, and timing of pollution events associated with mercury-related releases. Do you have a mercury related claim that is not progressing to closure? VERTEX’s claim management services can also help move remedial projects forward to regulatory closure in a timely and cost-effective manner.
In addition to our environmental insurance claims management services, VERTEX also has a team of experienced environmental professionals that can perform Phase I Environmental Site Assessments and/or Phase II Environmental Site Assessments.