MDEQ initiated a P2 partnership with MDA to protect Michigan dairy farms and the environment by reducing mercury on the farm. Mercury, also known as quicksilver, is a naturally occurring, odorless, silvery liquid with a metallic luster. It expands and contracts evenly with temperature and pressure changes, which makes it an ideal medium for use in vacuum gauges (manometers) such as the ones used on dairy farms. However, mercury has been identified as one of the primary pollutants of concern.

Mercury-containing manometers can be replaced with mercury-free alternative gauges.  The same goes for various thermometers and mercury switches.  If you need information on how to replace your mercury-containing gauges, please call the Department of Agriculture, Dairy Section at (517) 373-1086 or (800) 292-3939. Or you can refer to the Merc Concern: Mercury Awareness for Michigan Dairy Farmers (pdf).

One-quarter of the dairy farms in Michigan may have mercury manometers, each containing approximately one pound of mercury. These manometers carry the potential for serious risk and liability.

Mercury elimination reduces potential mercury spill that can be very costly and hazardous to one's health.  Potential costs associated with mercury include controlling, removing, and managing mercury contamination in the environment.  

Why Mercury is a Pollutant of Concern

• In Michigan, mercury has been identified as one of the primary pollutants of concern.
• Mercury is extremely toxic to the nervous system. Children and the unborn are most sensitive to mercury poisoning.
• If mercury is spilled, it can evaporate at room temperature and then is easily inhaled. You cannot see, smell or taste these vapors. Watch mercury in action.
• In Michigan along numerous mercury spills have occurred. In several instances children were hospitalized; and in once case, four people died.
• Short-term mercury exposure can result in such symptoms as nausea, shortness of breath, and bronchitis; however, mercury exposure can begin to cause harm even before symptoms arise.
• Long-term mercury exposure can result in such symptoms as shakiness, tremors, numbness in the fingers and toes, loss of muscle control, memory loss, and kidney disease.
• Mercury spills are extremely difficult to clean up. Usually a professional service is needed to adequately clean up the spill which can cost thousands of dollars.

Mercury in the Environment

When you look at the effects of mercury on the environment, it's easy to see why the reduction of its use is critical to the quality of life.

In the environment, mercury can be converted into methylmercury, a form which can build up in the tissue of certain species of wildlife such as fish.

On average, a gram (1/70 of a teaspoon) of mercury enters a 20-acre lake from the atmosphere every year which is enough to elevate the mercury levels in fish.

Methylmercury in large fish can be hundreds of thousands of times greater than that in the surrounding water.

Methylmercury levels in fish within lakes have resulted in Michigan, and at least 37 other states, issuing fish consumption advisories.

Currently 66% of Michigan inland lakes have some fish that exceed the trigger limit concentration for fish consumption advisories (0.5 parts per million [ppm]).

In extremely high concentrations, methylmercury poisoning can cause damage to the central nervous system, kidney and liver damage, impaired child development, and even death.  Particularly at risk are unborn children.