Teledyne Leeman Labs Blog

Mercury Testing in Water and Health Effects of Mercury in Drinking Water

How does mercury get into drinking water supplies? How do we know when our drinking water is polluted? How does mercury contamination impact human health? In this blog we will focus on the sources of mercury in the environment, discuss health risks associated with mercury exposure, examine water treatment for mercury, review existing regulation designed to monitor and mitigate mercury and highlight Teledyne Leeman Labs’ role in manufacturing analyzers that test for mercury in water samples.

Artisanal and small-scale gold mining (ASGM) is defined by the Minamata Convention on Mercury as ‘gold mining conducted by individual miners or small enterprises with limited capital investment and production’. This type of mining often uses liquid mercury which forms an amalgam with the gold ore in the soil. The very small particles of gold are dissolved into the mercury to form a dark grey clump. To release the gold from the amalgam, the alloy is melted over a flame, driving the gaseous mercury vapor into the air and leaving behind the extracted gold. It is estimated that ASGM produces up to 20% of the world’s gold and 35% of all mercury pollution into the environment. Gold mining using mercury is detrimental to the health of workers, their environment, and their communities but there are economic and social considerations that limit the implementation of mercury free mining technologies.

Mercury is well known to international agencies as toxic and a risk to human health. And yet, mercury is a common ingredient in cosmetic skin whitening creams due to its bleaching effect on skin. Repeated topical application can cause mercury to accumulate in the body as it is easily absorbed through the skin as well as through the lungs by inhalation. Applying these creams repeatedly and for prolonged periods of time can cause numerous adverse health effects. Mercury is still being added as an ingredient despite the known health concerns associated with it.

Despite its remote location, the Amazonian basin is not immune to mercury contamination. A new study published in the Environmental Toxicology & Chemistry found the presence of mercury in two species of turtles and two species of caiman. The concentration of the mercury was below World Health Organization consumption guidelines, but the mercury levels in the liver were higher than recommended for children and pregnant women.

What Is Mercury and Why is it Toxic?

Mercury is a metallic element with the symbol Hg and is the only liquid metal at room temperature. Mercury’s zero oxidation state (Hg⁰) exists as a liquid or vapor, its mercurous state (Hg⁺) forms inorganic salts, and its mercuric state (Hg⁺²) exists as either inorganic salts or organomercury compounds. With the exception of elemental liquid mercury, all forms of mercury are toxic, and some deadly.

The familiar Florida summertime clap of daily thunder signals to the kids playing ball outside that it is time to go inside for a bit.  Any U.S. Gulf Coast kid knows when the thunderstorm clouds roll overhead to get to shelter—fast--- because next to come are the threatening lightning strikes. While the lightning is a dangerous concern, the invisible pollution dangers from thunderstorms may be even worse than the lightning strikes. 

The Mercury Deposition Network has evaluated rainwater nationwide for twenty years.  It has puzzled analysts as to why the mercury levels were persistently so much higher in the southeast, especially in the Gulf Coast states of Florida and Louisiana, than those of northern states.  

Spearheading a global group of scientists, the U.S. Geological Survey chronicled the mercury pollutants in the air, soil, sediment, plants, fish and wildlife throughout western North America.  Ecologists complied decades of data and studies to assess groupings of mercury and methylmercury.

Mercury, a heavy metal, is organically found in the rock of the earth’s crust.  It can become problematic when people, fish, and wildlife are subjected to elevated levels of mercury in its harmful configuration, methylmercury. 

Illegal gold mining operations in Peru have forced the Peruvian government to declare a state of emergency for the next two month. While the gold is valuable, the extracted process from surrounding areas has created a major health problem for local residents.

In 2012, the Environmental Protection Agency adopted new emissions standards that were directed at cutting power plant emisions of mercury and other toxic air pollutants. On June 29, 2015, the U.S. Supreme Court rejected the rules with a vote of 5-4 citing the costs of the regulations to power plant operators. The EPA estimated the rules would force companies to spend $9.6 billion a year on compliance while saving Americans between $37 billion and $90 billion a year from premature death and reduced health complications. The decision reverses a D.C. Circuit Court of Appeals decision that called mercury emissions a “threat to the public and the environment.”

Mercury is a common element found in the lab, particularly in thermometers, barometers, manometers and sphygmomanometers. Given the danger of mercury, many of these instruments are being phased out in place of more environmental- and health-friendly options. As far back as 1991, the Environmental Protection Agency regulated mercury out of latex paint, and in other industries such as pharmaceutical and agricultural, it is being used less and less.

There are three forms of mercury inorganic, organic and elemental mercury, which is most common in the lab. Each is toxic, but organic mercury, which forms in nature, contaminates fish and pollutes waters. Elemental mercury is a silvery and odorless liquid at room temperature, and is the most common source of occupational exposure. The vapors from a spill can “affects the central nervous system (CNS), producing tremors, mood changes and reduced cognitive, sensory, and motor nerve functions. The kidneys are also affected, with renal failure at extremely high doses.”[i]