Rolling back Mercury Air Toxic Standards is a bad idea

Rolling back Mercury Air Toxic Standards is a bad idea

My first job as a research chemist was at a research center for a steel-production facility. People who are not familiar with the steel-making process may be unaware of the large amounts of foods that were once packaged in some type of steel-based container.

Through the 1980s Ohio Valley steel mills produced the majority of tinplate used to pack light-colored fruits grown in the United States.

Tinplate is basically a thin steel sheet that has been electroplated or hot dipped with a layer of tin. One place to find an example of tinplate is on the inside lining of a can containing light-colored fruits such as pears, peaches or pineapples. If you open the can and look inside, you can see the crystal pattern of tin.

This pattern is similar to what you see on your zinc plate ductwork of your furnace. These crystal patterns are created when molten zinc or tin solutions are applied to raw iron sheets or coils of steel.

Tinplate has been used for food packaging since the 1930s when items such as cocoa, biscuit mix and dried dairy products were packed in metal tins. For decades we have eaten pears, peaches and pineapples from unlacquered tinplate cans, and in each bite is a tiny amount of tin.

Tin, in low concentrations (around 2 ppm), does impart some taste to those fruits. If you doubt this, buy these fruits packaged in glass. There is a noticeable difference in the taste.

Is eating this amount of tin toxic? The CDC says no. Tin exposures from foods packed in tinplate are negligible, and the tin is quickly excreted by the body. All metals differ in toxicity, however, and one we should never ingest or inhale is mercury.

Most of us older folks remember the days of mercury-filled glass thermometers. Just thinking about putting a toxic heavy metal encased in glass into one’s mouth is disturbing to say the least. Elemental mercury, the type in a thermometer, is more dangerous as an inhalation hazard than when ingested. This is why you should never vacuum up a mercury spill. You vaporize the metal atoms, making them easier to inhale.

Mercury becomes more toxic when released into the environment. Once it is exposed to naturally occurring anaerobic bacteria found in soils, sediment and water, mercury can be methylated.

These bacteria can actually splice methyl groups (methane molecules lacking one hydrogen) onto a mercury atom. Methylmercury can be easily absorbed into the body. Most of our exposure to methylmercury comes from eating fish and shellfish that have been feeding in waters subjected to mercury via air pollution.

That airborne mercury originates primarily from the burning of coal in coal-fired power plants. Ohio is second only to Texas in the amounts of mercury produced from electrical power generation.

In Ohio all bodies of water in the state have some amount of mercury pollution from coal-burning power plants. According to an EPA report, “Every fish sample tested from Ohio and throughout the nation was contaminated with mercury.”

Several of Ohio’s most popular sport fish contained mercury levels that exceed the U.S. EPA’s safe limit for women of childbearing age including 48 percent of the walleye, 49 percent of the smallmouth bass, 50 percent of the northern pike and 64 percent of the largemouth bass.

Unfortunately many citizens of the state disregard these warnings and consume larger than recommended quantities of fish caught in Ohio waterways.

Mercury is most notorious for its ability to affect the neurological systems of the human body. The Mad Hatter went mad from exposure to the mercury compounds he used when curing felt for the hats he was making.

When I was a teenager, I read a disturbing article in Life Magazine. It was a photo essay titled “Death-Flow from a Pipe.” The photographer, Eugene Smith, chose a cover photo showing a black and white image of a mother in Minamata, Japan bathing her emaciated adult daughter. The daughter was a victim of mercury poisoning, poisoned in her mother’s womb. She was deaf, blind and unable to use her legs.

Minamata, Japan is a fishing village on an island adjacent to the mainland. In the early 1900s a chemical company established a factory near the small town. The factory grew into a major chemical producer for Japan. For decades it dumped its wastes into Minamata Bay. As early as 1925 the local fisherman began to complain about the pollution. Their complaints were ignored.

By the 1950s both aquatic and land species of animals were showing ill-health effects. Insanity, paralysis, coma and death, along with birth defects, were reported in villagers.

People reported cats and pigs were going mad. In a society where dissent is frowned on, it took years for many of the victims to come forward. Even then the company never accepted responsibility for the pollution and poisonings.

In a recent Reuter’s report, the current U.S. EPA said it was “proposing that it is not appropriate and necessary to regulate Hazardous Air Pollution emissions from coal and oil-fired power plants because the costs of such regulation grossly outweigh the quantified HAP benefits.”

Its reassessment showed the cost of compliance with Mercury Air Toxic Standards or MATS was between $7.4-$9.6 billion annually while the monetized benefits were between $4-$6 million. In contrast the Obama-era EPA monetized the annual health benefits at $80 billion.

Ironically most coal-fired power plants have already taken costly steps to meet previous MATS standards enacted in 2011. However, in December 2018 the Trump administration announced these standards were “too costly” and wants them “rolled back.”

Paracelsus, an alchemist born in 1493 and the father of modern toxicology, said, “The dose makes the poison.”

In the case of mercury, the safe level for a 132-pound woman, according to the EPA, is 6.0 mg per day or approximately one meal of fish per week depending on fish species.

Given the toxicity of this element and the costs to human health and the environment, rolling back MATS is a bad idea.

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