Fish from Florida Mine Site Test Toxic for Mercury

The finding was determined after review of sampling data by a Department of Health, DOH, health assessment program funded by the federal Agency for Toxic Substances and Disease Registry, ATSDR.

Hazardous levels of mercury were found in the bass during recent testing at the limestone mine, two state agencies agree.

The Florida Department of Environmental Protection tested largemouth bass caught in the ponds and requested that DOH review the data to see if the fish were safe for people to eat. After reviewing the data, DOH also found increased levels of mercury in the fish samples.

The fish beneath these waters at the Kirby mine site contain high levels of mercury. (Photo courtesy Florida DEP)

An ATSDR health consultation on the Kirby Mine published in August, evaluated the Florida DEP's fish testing results from July 2003, April 2005 and January 2006.

Mining operations at the Kirby Mine occupy 80 acres of a 302 acre parcel adjacent to the Columbia City Mine site. Both mines operated for decades as limestone quarries.

Mining operations ceased at both sites when purchased by the state of Florida in 2000 and 2001. Florida purchased these properties to prevent impacts of the mining on nearby Ichetucknee Springs.

Kirby Mine has large water filled pits, spoil piles and various abandoned service facilities such as scale houses, loading areas and process areas.

This investigation was initiated because the Florida DEP found metals in soils on the site near the mining pits and asked the Florida DOH to review the fish data.

Florida DEP's Office of Greenway and Trails wants to allow recreational fishing in the ponds, but eating the fish, especially large-mouthed bass, is the exposure pathway of concern.

Women of childbearing age and young children are especially sensitive to mercury and should only eat one six-ounce meal per month of cooked largemouth bass from the ponds, the DOH recommends, adding that anyone else eating largemouth bass from the ponds should limit consumption to one meal per week.

In 2003, Florida DEP tested soil, surface water, and ground water at this site. They found mercury, chromium, and lead in the soil; low levels of arsenic and barium in the surface water; and low levels of silver, mercury, and chromium in the ground water.

Based on the 2000 census, approximately 589 people live within one mile of the Kirby Mine site. Of this population, 90 percent are white, seven percent are black and three percent are Hispanic or from other racial/ethnic groups.

Neither Florida DOH nor Florida DEP have received health concerns from nearby residents.

Health experts generally agree that eating fish is an important part of a healthy diet. Rich in vitamins and low in fat, fish is high in protein for growth and development. The American Heart Association recommends that most people should generally eat two meals of fish or seafood a week.

Levels of mercury found in fish vary depending on the age and type of fish, as well as the condition of the fish's environment. Methylmercury builds up in the tissues of fish, so larger and older fish tend to have the highest levels of mercury.

To lower the risk of harm from mercury found in fish caught in Florida, see guidelines based on tests of various water bodies.

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