With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.

Mercury is an interesting metal, it is the only metal that is liquid at room temperature, and although it’s heavy, it’s slippery. A single tablespoon of this fascinating element weighs around ½ lb, and it is hazardous to humans. Liquid mercury emits fumes that can cause major health problems if inhaled: mercury can enter the water supply, and long-term exposure can cause a number of serious health issues. In this article, we will take a closer look at the dangers of mercury exposure and how you can remove it from your water supply.

What is Mercury?

Mercury (Hg) has been known as quicksilver throughout history, and it has been a fascinating metal for people to study because it holds a liquid state at room temperature. But, studying mercury too closely without adequate protection is ill advised because it’s a potent neurotoxin. An object that contains mercury, such as a thermometer that breaks, will distribute droplets that evaporate into an odorless and toxic gas. In recent years the dangers of mercury exposure have been widely studied, and we know more than our predecessors. We don’t know how many people throughout history have experienced deleterious health effects due to mercury exposure. But, many products that historically contained mercury are now banned, and this includes fever thermometers. In 2001 many state and city governments implemented restrictions on thermometer manufacturing processes that used mercury.

Why is Mercury in Water?

The vast majority of mercury found in water sources go there as a result of atmospheric deposition. This is when gasses found in the atmosphere fall in rain or snow or even as dry particles onto the ground or surface water sources. Some other sources include industrial waste materials, volcanic activity, naturally occurring deposits, mining waste, and more. mercury is still used in the manufacturing of products, including automotive parts, thermostats, fluorescent lights, LCD screens, certain types of batteries, and more. Although some of these processes and products may be banned, they may still be present in the electronic and electrical industries and coal-fired power plants. mercury waste may be flushed into surface water supplies and underground aquifers through rainwater runoff and storm activity.

Is Mercury in Drinking Water Dangerous?

Yes. Mercury is extremely toxic, and even low-level exposure can have fatal consequences. There is no need to ingest mercury into the body, and poisoning usually occurs when the gas is inhaled. But. it is possible to absorb mercury through the skin too, but this takes time, and inhalation of mercury gas is a more immediate health threat.

What are the Effects of Mercury Poisoning?

The effects of Mercury poisoning may vary depending on the level of exposure and if that exposure took place over a short-term or long-term period of time. Other key factors in the severity of mercury poisoning include the age of the person exposed, the form of mercury, the amount of mercury present, prior medical issues, and the exposure time. There are two different types of mercury poisoning that we will cover below:

1.   Elemental Mercury Poisoning

This is caused by direct exposure to spilled metallic mercury in a liquid state. This can occur when certain products and household items are broken, such as blood pressure gauges, older light bulbs, old thermometers, fluorescent light bulbs, thermostats, and others. Exposure to elemental mercury can lead to a number of health effects, including headaches, tremors, insomnia, mood swings, reduced mental cognition, and a decrease in the level of nerve responsiveness.

2.   Methylmercury Poisoning

This is the mercury poisoning that is more likely to be a problem in water sources. It’s found in water, fish, and shellfish. It’s particularly dangerous for infants and children because it causes brain and nervous system damage. Exposure can occur when seafood is eaten, which adversely affects the mental and physical development of children. Private well water is a common source of methylmercury, city water is tested, but it can contain dangerous concentrations of mercury. Any person with a blood-mercury level that exceeds 100 parts per billion (ppb) will experience some or all of the following symptoms: hearing loss, lung impairment, muscle weakness, a lack of coordination, vision loss, and even cerebral palsy in infants.

Does My Tap Water Contain Mercury?

Public water must contain less than 0.002 parts per million (ppm) or 2 ppb of mercury to meet the EPA standards. These levels would pose no health threat even if exposure occurred over a long-term period. Human error may occur, and a break in the water delivery infrastructure could allow mercury to enter the water supply. That said, homes supplied with private well water are at a greater risk of mercury poisoning than public water users.

Does My Private Well Water Contain Mercury?

Yes, most well water sources contain mercury in some concentration, but these may have a concentration well below the danger threshold. Certain states are more prone to dangerous levels of mercury than others, and the East Coast of the U.S. is very prone to this problem. High levels of air pollution, volcanic activity, coal-fired power plants, natural deposits, and mining waste can all increase the mercury concentration. As we mentioned earlier, this is caused by atmospheric disposition, and the mercury can settle in the soil, surface water, and groundwater sources.

How Can I Remove Mercury from My Water?

The first step should be to use a mercury test kit to determine if the mercury level is dangerously high. If you have a mercury problem, there are three water filtration systems that can remove this toxic metal: reverse osmosis (RO), activated carbon and carbon block filters, and water distillation.

1.   Reverse Osmosis (RO)

This system has a minimum 3-stage filter system with a semi-permeable RO membrane that can remove 95-97% of mercury from drinking water.

2.   Activated and Carbon Block Filters

These remove contaminants, such as chlorine, lead, mercury, and more, in a similar way. They can also be found in standalone appliances like water pitchers and refrigerators.

3.   Water Distillation

These systems boil water and collect the vapor to create clean water. But. for everyday use, they are impractical because they take time to use and consume a lot of energy.

If you want to install a water filtration system that can remove mercury, contact your local water treatment specialist.