Students who seem to love those underwater creatures might want to think twice the next time they order at their favorite seafood restaurant.
Matt Chumchal, associate professor of biology at Texas Christian University discussed in lecture the potential causes and consequences of Mercury (Hg) contamination on Thursday, Oct. 22. The lecture, hosted by The Biological Sciences Department, discussed mercury in the environment, the Texas region, and at Caddo Lake.
Chumchal, along with many collaborators and Texas Parks and Wildlife, studied the affects of mercury contamination for the past several years.
Mercury contamination, according to Chumchal, is one of the most important environmental problems facing the world we live in. There are high levels of mercury in almost every ecosystem around the world, and is found in the Pacific, in the tropics, and remote arctic regions. The United States has a relatively small amount, while Asia has a great amount.
Mercury makes its way into the environment from natural and anthropogenic sources that combine to release inorganic mercury in the atmosphere. Inorganic mercury can suspend in the atmosphere up to two years.
From there, mercury ends up washed through wetlands, reservoirs, and lakes. It can be converted by bacteria into a very toxic form of mercury called Methyl mercury. Mercury is usually found in the water in very low concentrations. These concentrations are so low that you can even drink or swim in it with no harm. It goes through biomagnification, a process that means there is a higher concentration the higher up on the food chain.
Mercury has many known negative affects on humans. It can affect the cardiovascular, immune, and reproductive systems. These are the concentrations that a human would be exposed to when eating fish. It becomes a problem for humans because fish are an important part of the our diet. Pregnant women are at a greater risk from mercury contamination. Those who consume fish or aquatic beings with high mercury concentrations run the risk of harming the fetus.
“This is mainly a problem for pregnant women, because fetus’ are harmed by concentrations of Hg that are much lower than the what an adult would be harmed by,” Chumchal said.
Between one and six women have concentrations in their blood high enough to harm the fetus if the woman became pregnant. The fetus could be at risk for possible neurological problems.
The contamination has no geographic pattern, yet in Texas there’s almost none. In the surrounding states (Oklahoma, Louisiana, Arkansas, New Mexico), the highest contamination is in Louisiana. Most lakes in East Texas are under fish advisories, “the way that states want citizens about the presence of Mercury in fish.”
“The take home message is that most states in the country have fish advisories.”
The good news is that now, with the studies of Matt Chumchal and collaborators, there is more information available about mercury in the environment. Don’t worry, you can still eat fish, just watch how much you consume.