The toxic threat in thawing permafrost

Read the full story in Hakai Magazine.

Scientists are tracking neurotoxic methylmercury production in North America’s largest peatland.

Farewell to fluorescent lighting: How a phaseout can cut mercury pollution, protect the climate, and save money

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Mercury-free LED replacements for linear and compact fluorescent bulbs are widely available and provide the same or better lighting, longer product life, and much lower total cost than fluorescents. This study finds that drop-in LED replacement lamps are available for all common linear fluorescent tubes, pin-based compact fluorescent lamps, and specialty applications. Policies to accelerate the phaseout of fluorescent lighting and a full transition to LED lighting would eliminate a significant source of mercury pollution and its threat to human health and the environment. Government policies to limit mercury have often exempted fluorescent lighting—the most common use of mercury in homes and commercial buildings—because ready-to-go, mercury-free substitutes did not exist. Our findings show that such exemptions for fluorescent lighting are no longer necessary.

How poisonous mercury gets from coal-fired power plants into the fish you eat

Coal-fired power plants are a source of mercury that people can ingest by eating fish. Mark Wilson/Getty Images

by Gabriel Filippelli, IUPUI

People fishing along the banks of the White River as it winds through Indianapolis sometimes pass by ominous signs warning about eating the fish they catch.

One of the risks they have faced is mercury poisoning.

Mercury is a neurotoxic metal that can cause irreparable harm to human health – especially the brain development of young children. It is tied to lower IQ and results in decreased earning potential, as well as higher health costs. Lost productivity from mercury alone was calculated in 2005 to reach almost $9 billion per year.

One way mercury gets into river fish is with the gases that rise up the smokestacks of coal-burning power plants.

The Environmental Protection Agency has had a rule since 2012 limiting mercury emissions from coal-fired power plants. But the Trump administration stopped enforcing it, arguing that the costs to industry outweighed the health benefit. Now, the Biden administration is moving to reassert it.

I study mercury and its sources as a biogeochemist at Indiana University-Purdue University Indianapolis. Before the EPA’s original mercury rule went into effect, my students and I launched a project to track how Indianapolis-area power plants were increasing mercury in the rivers and soil.

Mercury bioaccumulates in the food chain

The risks from eating a fish from a river downwind from a coal-burning power plant depends on both the type of fish caught and the age and condition of the person consuming it.

Mercury is a bioaccumulative toxin, meaning that it increasingly concentrates in the flesh of organisms as it makes its way up the food chain.

A person's hands old a smallmouth bass, with the fish's mouth open
Mercury accumulates as it moves up the food chain. doug4537 via Getty Images

The mercury emitted from coal-burning power plants falls onto soils and washes into waterways. There, the moderately benign mercury is transformed by bacteria into a toxic organic form called methylmercury.

Each bacterium might contain only one unit of toxic methylmercury, but a worm chewing through sediment and eating 1,000 of those bacteria now contains 1,000 doses of mercury. The catfish that eats the worm then get more doses, and so on up the food chain to humans.

In this way, top-level predator fishes, such as smallmouth bass, walleye, largemouth bass, lake trout and Northern pike, typically contain the highest amounts of mercury in aquatic ecosystems. On average, one of these fish contains enough to make eating only one serving of them per month dangerous for the developing fetuses of pregnant women and for children.

How coal plant mercury rains down

In our study, we wanted to answer a simple question: Did the local coal-burning power plants, known to be major emitters of toxic mercury, have an impact on the local environment?

The obvious answer seems to be yes, they do. But in fact, quite a bit of research – and coal industry advertising – noted that mercury is a “global pollutant” and could not necessarily be traced to a local source. A recurring argument is that mercury deposited on the landscape came from coal-burning power plants in China, so why regulate local emissions if others were still burning coal?

That justification was based on the unique chemistry of this element. It is the only metal that is liquid at room temperature, and when heated just to a moderate level, will evaporate into mercury vapor. Thus, when coal is burned in a power plant, the mercury that is present in it is released through the smokestacks as a gas and dilutes as it travels. Low levels of mercury also occur naturally.

Although this argument was technically true, we found it obscured the bigger picture.

A view of the river with a bridge and the city in the background.
People sometimes fish along the White River where it flows through Indianapolis. alexeys via Getty Images

We found the overwhelming source of mercury was within sight of the White River fishermen – a large coal-burning power plant on the edge of the city.

This power plant emitted vaporous mercury at the time, though it has since switched to natural gas. We found that much of the plant’s mercury rapidly reacted with other atmospheric constituents and water vapor to “wash out” over the city. It was raining down mercury on the landscape.

Traveling by air and water, miles from the source

Mercury emitted from the smokestacks of coal-fired power plants can fall from the atmosphere with rain, mist or chemical reactions. Several studies have shown elevated levels of mercury in soils and plants near power plants, with much of the mercury falling within about 9 miles (15 kilometers) of the smokestack.

When we surveyed hundreds of surface soils ranging from about 1 to 31 miles (2 to 50 km) from the coal-fired power plant, then the single largest emitter of mercury in central Indiana, we were shocked. We found a clear “plume” of elevated mercury in Indianapolis, with much higher values near the power plant tailing off to almost background values 31 miles downwind.

The White River flows from the northeast to the southwest through Indianapolis, opposite the wind patterns. When we sampled sediments from most of its course through central Indiana, we found that mercury levels started low well upstream of Indianapolis, but increased substantially as the river flowed through downtown, apparently accumulating deposited mercury along its flow path.

We also found high levels well downstream of the city. Thus a fisherman out in the countryside, far away from the city, was still at significant risk of catching, and eating, high-mercury fish.

The region’s fish advisories still recommend sharply limiting the amount of fish eaten from the White River. In Indianapolis, for example, pregnant women are advised to avoid eating some fish from the river altogether.

Reviving the MATS rule

The EPA announced the Mercury and Air Toxic Standards rule in 2011 to deal with the exact health risk Indianapolis was facing.

The rule stipulated that mercury sources had to be sharply reduced. For coal-fired power plants, this meant either installing costly mercury-capturing filters in the smokestacks or converting to another energy source. Many converted to natural gas, which reduces the mercury risk but still contributes to health problems and global warming.

The MATS rule helped tilt the national energy playing field away from coal, until the Trump Administration attempted to weaken the rule in 2020 to try to bolster the declining U.S. coal industry. The administration rescinded a “supplemental finding” that determined it is “appropriate and necessary” to regulate mercury from power plants.

On Jan. 31, 2022, the Biden Administration moved to reaffirm that supplemental finding and effectively restore the standards.

More than a quarter of U.S. coal-fired power plants currently operating were scheduled as of 2021 to be retired by 2035. EIA

Some economists have calculated the net cost of the MATS rule to the U.S. electricity sector to be about $9.6 billion per year. This is roughly equal to the earlier estimates of productivity loss from the harm mercury emissions cause.

To a public health expert, this math problem is a no-brainer, and I am pleased to see the rule back in place, protecting the health of generations of future Americans.

Gabriel Filippelli, Chancellor’s Professor of Earth Sciences and Executive Director, Indiana University Environmental Resilience Institute, IUPUI

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dragonflies reveal mercury pollution levels across US national parks

Read the full story from Dartmouth College.

Research confirms dragonfly larvae as ”biosentinels” to indicate mercury pollution and presents the first-ever survey of mercury pollution in the U.S. National Park System.

Associated journal article: Collin A. Eagles-Smith, James J. Willacker, Sarah J. Nelson, Colleen M. Flanagan Pritz, David P. Krabbenhoft, Celia Y. Chen, Joshua T. Ackerman, Evan H. Campbell Grant, David S. Pilliod (2020). “A National-Scale Assessment of Mercury Bioaccumulation in United States National Parks Using Dragonfly Larvae As Biosentinels through a Citizen-Science Framework.” Environmental Science & Technology 54 (14): 8779 DOI: 10.1021/acs.est.0c01255

Trump Administration to Weaken Limits on Mercury and Other Toxic Pollutants

Read the full story at e360.

The Trump administration is expected to weaken regulations on mercury pollution from oil- and coal-fired power plants this week, several news outlets reported. The new rule will change how the U.S. Environmental Protection Agency calculates the costs and benefits of reducing releases of mercury and other toxic metals, undermining the legal justifications for limiting the pollutants.

2020 Mercury Inventory Report

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On March 30, 2020, EPA published the first in a series of triennial reports on the supply, use, and trade of mercury in the United States, supported by Agency’s mercury inventory reporting rule (an initial inventory report was published in 2017, prior to the rule that established reporting requirements). Based on the information collected under the mercury inventory reporting rule, the 2020 Mercury Inventory Report identifies any manufacturing processes or products that intentionally add mercury and recommends actions to achieve further reductions in mercury use.

The scientists restoring a gold-mining disaster zone in the Peruvian Amazon

Read the full story in Nature.

Months after the military expelled thousands of illegal miners from La Pampa, researchers gained access to a sandy wasteland.

Students chowing down tuna in dining halls are unaware of mercury exposure risks

Read the full story from the University of California – Santa Cruz.

Some students are helping themselves to servings of tuna well beyond the amounts recommended to avoid consuming too much mercury. Researchers surveyed students on their tuna consumption habits and knowledge of mercury exposure risks, and also measured the mercury levels in hair samples. Hair mercury levels were closely correlated with how much tuna the students said they ate. And for some, the measurements were above what is considered a ‘level of concern.’

Webinar Series on the Mercury Inventory Reporting Rule of the Toxic Substances Control Act (TSCA)

EPA is hosting two webinars for companies, organizations, and individuals required to report under the Mercury Inventory Reporting Rule of the Toxic Substances Control Act (TSCA). The final rule requires persons who manufacture (including import) mercury or mercury-added products, or otherwise intentionally use mercury in a manufacturing process, to submit their mercury information to EPA using the online Mercury Electronic Reporting (MER) application. This information will be used to develop triennial inventories of mercury supply, use, and trade in the United States.

A webinar providing background on reporting requirements under the final rule, such as who must report under the final rule and the required reporting information, will take place on Tuesday, May 21, 2019 at 2 PM ET. Following EPA’s presentation, webinar participants will have an opportunity to ask questions on reporting requirements under the final rule.

To participate in the “Mercury Inventory Reporting Rule” webinar, please register on Eventbrite at

A second webinar demonstrating how to use the online MER application through EPA’s Central Data Exchange (CDX) will take place on Thursday, May 23, 2019 at 2 PM ET.

To participate in the “Mercury Electronic Reporting (MER) Application” webinar, please register on Eventbrite at

For more information on the Mercury Inventory Reporting Rule, visit EPA’s Mercury website at

Critics pounce on EPA’s mercury proposal

Read the full story in Greenwire.

EPA officials confronted a chorus of calls this morning to drop plans for revisiting their landmark regulation of power plant mercury pollution as speakers at a public hearing accused the agency of industry bias, flawed analysis and sheer wrongheadedness.