Sitting at the bottom of Onondaga Lake, there are currently 7 million cubic yards of soil contaminated with methylmercury, the most dangerous form of mercury. This contamination for years has threatened the health of surrounding humans and wildlife.

Allied Chemical Corp., currently known as Honeywell International, Inc., was responsible for the discharging of 165,000 pounds of mercury into the southwest portion of Onondaga Lake due to the mass production of chlorine over the course of thirty plus years.

Cleanup has been ongoing for decades, but local fish are still contaminated with unsafe levels of methylmercury. The state and federal governments must double down on their efforts to make fishing safe.

Starting as early as the 1940s and continuing throughout the 1960s, Allied continuously discharged large quantities of methylmercury into Onondaga Lake until the company was sued by the U.S. Attorney General in 1970. Dumping of mass amounts of mercury into the lake halted, but the damage was already done.

 Methylmercury is an organic form of mercury. Large quantities of methylmercury pollution are responsible for the health hazards that are associated with eating game fish from the lake. Methylmercury is known to be particularly toxic to the central and peripheral nervous systems of children and adults alike.

The consumption of methylmercury can lead to severe long-term health issues, including damages to the digestive and immune systems, kidney failure and development of other debilitating diseases. As a neurotoxin, methylmercury can also cause potentially permanent brain damage, which is especially dangerous in developing children.

The recommended maximum safe level of methylmercury to consume from large game fish is no more than 0.3 pm. However, large game fish, such as largemouth bass, that are found in Onondaga Lake can have methylmercury levels of roughly 0.6 ppm — twice the safe consumption level.

Charles Driscoll, a professor of environmental systems at Syracuse University, says that there has been an advisory against eating fish caught from Onondaga Lake for many years. Despite recent decreases in methylmercury levels in game fish, these fish still aren’t safe for consumption.

“People in surrounding areas like to fish at the lake and eat what they catch, which leads to consumption of higher than suggested levels of methylmercury,” he said. “The agreed-on amount of methylmercury to consume is about 0.3-0.4 ppm, but fish like largemouth bass are still way above this and shouldn’t be consumed.”

Driscoll also mentioned that there is a large variety of different birds who fish at Onondaga Lake alongside humans who are at risk for exposure. Methylmercury exposure in birds often results in interruptions to the reproductive behaviors, such as numerous effects to their overall health and condition.

Within the last decade, Onondaga Lake has seen successful clean-up projects that have helped to decrease the amount of mercury that is found in the lake. Through a lengthy process called “soil washing,” roughly 7 tons of mercury were able to be removed from the lake. An on-site groundwater collection system was built, as well as an underground, almost five-story deep wall meant to prevent future runoff.

 The removal of 7 tons of mercury from Onondaga Lake serves as a reminder to be optimistic about cleaning up the pollution that humans have caused. Decreased levels of methylmercury found in largemouth bass and other large game fish demonstrates that change is possible.

However, there are still an estimated 7 million cubic yards of contaminated soil left, and some large game fish still do not have appropriate levels of methylmercury to make them safe for consumption, despite all of these efforts. Fish caught from Onondaga Lake are not safe to eat. 

More soil washing should be implemented to continue decreasing methylmercury levels in the lake. This will not only benefit humans, but the birds that fish at Onondaga Lake, and the fish that make the lake their home. 
Samantha Kolb is an environmental studies major at SUNY-ESF. Her column appears bi-weekly. She can be reached at sakolb@syr.edu. She can be followed on Twitter at @SamiiKolby.

Published on September 23, 2020 at 9:21 pm