mercury

Lester Graham / Michigan Radio

Over the last decade, women have switched to making much healthier choices at the seafood counter.

First, let's make it clear: fish is healthful food.

But, fish can contain traces of mercury, some fish more than others. And to make sure you don’t consume too much of that toxin, you need to know which fish have heavier loads of mercury.

Why?

Because mercury is a toxic contaminant that can cause neurological damage. For women who could have children or who are pregnant, too much mercury could mean developmental problems for their babies.

Lindsey Smith / Michigan Radio

More than a hundred scientists from Michigan are supporting a federal standard that would limit the amount of mercury coal plants could emit.

The State of Michigan already has set some limits. But a major portion of the mercury that ends up in Michigan comes from coal plants in other states.

There are some U.S. Senators trying to stop federal regulators from implementing the rules. They say the regulations will hurt the economy.

Photo by Laura White

Mercury is a neurotoxin. The Environmental Protection Agency says mercury can be especially harmful for babies and kids. Mercury can affect their developing brains and harm their memory, attention, language and motor skills.

Mercury is naturally-occurring. Volcanoes emit mercury and so do hot springs, like the ones in Yellowstone National Park.

But the EPA points out... the largest manmade source of mercury emissions in the U.S. comes from coal-burning power plants.

Joel Blum is a professor of Earth and Environmental Sciences at the University of Michigan. Blum says when power plants burn coal, mercury is emitted as a gas.

“In order to become toxic, it has to be transformed into a particular form known as methylmercury which is something that happens in the environment.”

So... mercury falls from the atmosphere, and is converted to methylmercury in the water. That toxic form builds up in fish... and it can build up in us when we eat fish.

But for years... there’s been a big debate about where that mercury goes when it’s released from a power plant smokestack.

“How much is deposited nearby, close to the plant, and how much goes into what we call global pool of mercury - basically goes into the atmosphere and stays there for a long period of time and mixes with mercury from other sources.”

Joel Blum and his colleagues have started to crack that puzzle with some careful detective work. They were able to track mercury emissions from a power plant in Florida... and they found that a high proportion of the mercury ended up nearby.

They did this by looking at chemical fingerprints.

DTE's St. Clair Power Plant in East China, Michigan.
user cgord / wikimedia commons

A new report from the group Environment Michigan says 115 inland lakes and rivers in the state have advisories for mercury pollution. Eating contaminated fish is the main way people are exposed to mercury.

Jessica Surma is with Environment Michigan. She says children are especially at risk for adverse health effects from mercury exposure.

“These can include lowered IQs, developmental disabilities and problems with motor control.”

The Environmental Protection Agency says electric utilities are by far the largest manmade sources of mercury emissions in the U.S. The EPA is planning to regulate mercury from power plants – for the first time ever.

John Austerberry is with DTE Energy.

“We agree with the goal of those regulations, but we are concerned that the federal rules will not provide sufficient time for the utilities to plan and install control systems.”

He says the company doesn’t know yet how much any new mercury control systems might cost or how much of that cost they might pass on to customers.

Mariner 10 / NASA

Today is a big day for lovers of the planet Mercury, the closest planet to the sun.

NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) vehicle will start to orbit Mercury today.

Of all the terrestrial planets, Mercury remains one of the most mysterious.

NASA's Mariner 10 took some photos during flybys back in 1974 and 1975. And more recently, MESSENGER took some photos and grabbed some samples on a flyby in 2008.

The New York Times had a piece on what scientists learned about Mercury from the 2008 flyby:

An instrument aboard Messenger sampled Mercury’s surface composition by catching some of the charged atoms that have been knocked into space. Silicon, sodium and sulfur were detected. So was water.

“Which is a real surprise,” said Thomas H. Zurbuchen, an associate professor of atmospheric, oceanic and space sciences at the University of Michigan and lead author of another paper in Science. “The first time we took a whiff of the planet, it’s right there.”

One possibility is that the water exists as ice in the shaded parts of craters in the polar regions.

Today, MESSENGER will begin orbiting the planet every 12 hours. Engineers at the University of Michigan say "an onboard device dubbed FIPS (Fast Imaging Plasma Spectrometer), a soda-can sized sensor designed and built at the University of Michigan will take atmospheric measurements, studying the evolution of rocky planets as it orbits Mercury."

Here, Thomas Zurbuchen, the lead engineer from the University of Michigan, talks about FIPS: