The American alligator’s tail can regenerate giving them a functional advantage when living in murky aquatic habitats via Awesome facts

The American alligator’s tail can regenerate like that of other reptiles

Some lizards have developed strategies to regrow their docked tails, but until now little was known about the much larger American alligator’s ability to regenerate it. A team of scientists has discovered that the youngest alligators can recover part of this limb, but this differs from the original structure.

The case of the lizards, with their “removable” tails, is well known. These small vertebrates are capable of re-creating nerve cells, like other lizards, and regenerating this limb. The strategy of shedding the tail is common to escape predators, but what about much larger reptiles, such as the American alligator?

So far, it was not well documented if this crocodilian, one of the largest in the American continent, could have this ability to recover its enormous tail. A team from Arizona State University and the Louisiana Department of Wildlife and Fisheries, both in the United States, shows for the first time that the youngest specimens, caught in the wild, had recovered their tail up to 18% of the full length of their body, although they were morphologically different from the original sections.

To analyze the structure of the regenerated limbs, the scientists performed MRIs and X-rays combined with anatomical and tissue organization studies. The results, published in the journal Scientific Reports, showed that the new tails lacked skeletal muscle – unlike other lizards – and formed complex structures with a central skeleton composed of cartilage and surrounded by fibrous connective tissue intertwined with blood vessels and nerves.

“What makes the alligator interesting, apart from its size, is that the re-growing tail shows signs of regeneration and wound healing within the same structure,” explains Cindy Xu, lead author and researcher at the American university.

This overproduction of connective tissue was similar to wound healing or fibrosis in mammals, the scientists found. “We were surprised to discover scar-like connective tissue rather than skeletal muscle in the regenerated crocodile tail,” Xu adds.

The partial limb growth of these crocodiles does share similarities with the regenerated tails of New Zalanda tuataras and the regenerated limbs of adult Xenopus frogs, which have a cartilaginous endoskeleton surrounded by connective tissue without skeletal muscle.

What does regeneration contribute?

The study confirms that between the different species of reptiles and other animals, the regenerative capacity varies, and can be costly. In the case of American alligators (Alligator mississippiensis), scientists believe that regenerating their tails can give them a functional advantage when living in murky aquatic habitats.

The regenerated alligator tail is different from the original. Although the scales grow back, a tube of cartilage (in yellow) replaces the bone (in ocher) and skeletal muscle does not reappear (in red). In its place is a large amount of fibrous connective tissue (in pink). / Arizona State University

This finding provides more information on how reptiles are the only amniotes – a group of animals with backbones among which humans are found – to maintain the ability to recover their lost limbs. “The ancestors of alligators, dinosaurs and birds separated about 250 million years ago. The study shows that the alligators have retained the cellular machinery to regenerate complex tails while the birds have lost that capacity ”, emphasizes Kenro Kusumi, co-principal author, and professor and director of the School of Life Sciences of the University of the State of Arizona . So at what point in evolution was this ability lost? So far, scientists have found no evidence of fossils of dinosaurs, whose lineage led to modern birds, with regenerated tails.

Furthermore, understanding how different animals can regenerate tissues could help develop medical therapies, according to the researchers. The team hopes that these findings will uncover new therapeutic approaches to repair injuries and treat diseases such as arthritis

Some lizards have developed strategies to regrow their docked tails, but until now little was known about the much larger American alligator’s ability to regenerate it. A team of scientists has discovered that the youngest alligators can recover part of this limb, but this differs from the original structure. The case of the lizards, with […]

The American alligator’s tail can regenerate like that of other reptiles — Awesome Facts to learn on Virtual Science

Colorado Fire: Containment Grows, Crews Monitoring Lines For Heat via CBS Denver

Containment on the Grizzly Creek Fire near Glenwood Spring grew to 71%, up from 68% reported on Friday.

Absolutely fabulous pic via Grizzly Creek Fire: Containment Grows, Crews Monitoring Lines For Heat — CBS Denver

Freshwater Mussels via The Ephemeral Stag

 

Walking along the riverbanks, lake sides, and pond shores across the world are empty open shells that were once the shield of protection to many freshwater bivalves, also known as freshwater mussels. I, personally, have even seen shells mixed into “river rock” on playgrounds. When I was a child, I even cut my foot on one hiding in the tiny pebbles of my parks swing set. I never thought much about them. When we would go to the lake to fish or swim, I would collect them like I was a mermaid princess collecting pearls. I would take them home and keep them in my fish tank, which helped my fish live for years. My beta fish named “fish” lived over 6 years because of his little friends (or a parent who lied… time will never know). How little did I know that twenty years later I would be doing the exact same thing. This time instead of a mermaid princess, I get to act in a scientific and ecological manner.

Mussel beds die off due to pollution, water diversion and invasive species.

Worldwide some conservations and ecological organizations estimate upwards to 1,000 species of freshwater mussels and other organizations claim its more like 900 different species. North America houses a known 300 different freshwater mussel species. The US Fish and Wildlife Services claims the North America has the highest diversity in freshwater mussel species in the world. There are many hot spots for mussels in the US including but not limited to the Mid-West and the Appalachian Mountains. It is estimated that over 70% of the endanger freshwater mussels are found in these two areas. Tennessee by itself historically housed 129 of the nation’s freshwater mussel species. Now with in Tennessee, it is estimated to house only 40 species.

There are many types of species in one general area. Most can live harmoniously.

Pre-European Colonization (don’t get me started on that mess) times are in my opinion the most ecologically balanced times in North America. Natives understood the balance between nature and humans. The first uses of mussels in the now US, was by these Natives and was probably food based. Archaeologist and anthropologist have found multiple sites of discarded shells on the banks of rivers around tribal sites. They probably were not a primary food source for the tribes, but the evidence does point to a culinary use. Later, (when Europe sent a bunch of “Karenz” over) there was significant uptick in trade for the shells.

Mussel buttons

During colonization and Pre-Modern day (prior to 1970s), freshwater mussels were harvested from riverbanks by the masses not for food or trade but for buttons. Yes, buttons. The “clammers” would use boats and drag the river bottoms looking for mussel beds. They would then shell the poor creature, sand down the roughness, and punch holes through out the shell. These punch outs would then be polished and punched for buttonholes. This type of harvested lasted longer than it should have unfortunately. It wasn’t until the 1900, this type of industry slow due to massive die off of the natural mussel beds.

Dead mussels littering the banks of rivers.

So, what is so fascinating about freshwater mussels? Conservationist around the world are trying to save the species we have left. They act as a natural water filtration system as well as food for fish and castration. They are what is called a “niche” species. So basically, without them we won’t have freshwater ecosystems. They have a rough outer shell that is semi curved on both sides. The shell open for them to eat, breath, mate, and move (yes, they move). Inside is the organs and soft tissue. If you ever open one, it kind of looks like an oyster but smaller.

A freshwater mussel using a lure to bring a host fish close enough to release its offspring into the nose of the host fish.

Freshwater mussels can live in almost any collection of freshwaters from pond and stream all the way to lakes and major rivers. Each species has its preferred depth and habitat. Also, the majority of freshwater mussel need fish to act as a host when mating. Some will even use their soft tissue disguised as a fish or prey to lure in the host fish. These may seem like simple creatures on the surface but they in fact are surprisingly in genius.

A mussel bed on the river floor

While we try to restore, what a boat load of people destroyed, there are still massive problems in their ecosystem that threatens the survival of the species. During the decades between 1930s to 1970s and even later there were over 80,000 dams built in the US, in an effort to use hydro power and control water flows and regulate flood waters. As well as dams the US dug canals and channels to divert water flows. There are over 18,000 canals in the US to this date. Both cause problems for the freshwater mussel by many factors. The waters become deeper in areas that were shallow before which can cause less area the mussels can survive in. It stops or impinges on the migration of the host fish species, causing reproduction to dwindle.

Dead mussels along a pond bank

Newer problems like pollution is not only affecting the host and phytoplankton that they feed on but the mussels themselves. There are multiple studies showing the biological affects of heavy metals, chemical and other man made pollutants. These contaminations cause lower body mass, lowered behavioral movement, and lowered overall survivability for the individual. It’s like if you have to live in your neighbors trash dump. You can’t find food. You can’t find love. And you won’t survive long periods of time.

OLYMPUS DIGITAL CAMERA

Lastly, invasive species are also causing a threat to the native freshwater mussels. Many species will come in on boats from other areas and take advantage of the new area. Other mussels, like the Zebra Mussel of Russia, leach off others for nutrients and other sustainable substances. There are new policies of how to maintain and care for the boats traveling in different waters, in order to slow the progression of the spread. However, it will take a lot of help from us as humans to undo our mistake.

Invasive Zebra Mussels attached to a native freshwater mussel

Protecting endangered species should be a priority for conservationists. A creature like the freshwater mussel is overlook so many times. It is important to know how vital they are to the ecosystem and how not to cause them more harm. Things you can do to help the protect these creatures is 1. To vote in all elections. Do your research! 2. Cut down on plastic usage. Many plastics and industries run off contaminate the water. 3. Spread your knowledge! A lot of people don’t see freshwater mussels as creatures that need protection or that they even exist and why they are important.

Sources

https://blogs.scientificamerican.com/extinction-countdown/americas-freshwater-mussels-are-going-extinct-heres-why-that-sucks/

https://www.knowablemagazine.org/article/living-world/2019/hidden-strengths-freshwater-mussels

https://www.biologicaldiversity.org/campaigns/freshwater_mussels/index.html

https://www.nationalgeographic.com/animals/2019/12/freshwater-mussels-die-off-united-states/

https://molluskconservation.org/MUSSELS/What_Mussel.html

https://www.fws.gov/midwest/endangered/clams/mussels.html

https://xerces.org/endangered-species/freshwater-mussels/about

Walking along the riverbanks, lake sides, and pond shores across the world are empty open shells that were once the shield of protection to many freshwate

via Forgotten Mussels — The Ephemeral Stag

Cleaning up oil spills with hair via Science Everyday

Adsorption of oil with hair is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent.

What this means is that hair allows oil to coat, hence effectively absorbing it. And given the surface area, cheap costs, and renewability of hair, this is a great solution.

Hair clippings are a low-tech, yet remarkably effective method to tidy up oil spills In fact, a San Francisco-based environmental non-profit organisation, Matter of Trust, has collected donations of thousands of pounds of human hair to clean up after the thousands of oil spills that happen each year.

Oil spills are an example of the havoc humanity often wreaks on the environment. In the last thirty odd years, the issue of oil spills and their effects has become a much talked about topic (And for all the wrong reasons).

So, how does an oil spill happen?

Oil spills happens when liquid petroleum is released into the environment by vehicle, vessel or pipeline.

It happens on a large scale and is mostly seen in water bodies. We’re not talking about a few litres here and there. We’re talking about millions of litres of oil spilling into the ocean.

Take the case of the M/T Haven Tanker Oil Spill. This devastating event watched approximately 45 million litres of oil fall into the ocean. Not only is this a significant loss, but the damages inflicted upon the environment have long lasting consequences.

And this is just one oil spill out of the many. Hundreds of oil spills take place every year. The news of many which don’t even reach us. Crude oil can be released by tankers on land. In water bodies, the spill occurs due to drilling rigs, offshore oil platforms and wells.

While the sources of oil spills are many, the solutions are limited.

Oil floats on water and prevents sunlight to pass through it. The shiny substance that you see sometimes on top layer of water is nothing but oil which makes it difficult for plants and sea animals to survive.

Underwater plants die. Oil weighs down the wings of birds that can no longer fly easily. It contaminates food, water and destroys the entire ecosystem.

See the source image
Birds struggling in oily water. Retrieved from https://www.latimes.com/nation/la-na-gulf-anniversary-20150418-story.html

Unfortunately, cleaning up of oil spill is no easy task. Various factors need to be considered before carrying out operations. Some of them being amount of oil spilled, temperature of water, type of beaches and many more.

Currently methods used involve skimmers, dispersants an bio degradant technology. But is there a better way?

The answer lies in your hair.

Have you ever noticed how your hair becomes greasy when you don’t wash it for a while? Why does this happen? It happens because hair is adsorbent.

Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent.

What this means is that hair allows oil to coat, hence effectively absorbing it. And given the surface area, cheap costs, and renewability of hair, this is a great solution.

Hair can also be washed repeatedly and this does not damage its ability to absorb oil. The average person takes around 150 haircuts in their lifetime. Hair is low-cost, easily available and a great alternative to chemical treatments.

This idea was the brainchild of Phil McCrory, a former hairdresser from Alabama and it has the potential to change the environment completely.

One of the most important takeaways from this, is how simple solutions can be used to bring around large change. I hope this encourages each one of you to try learning new things. Because, the solution of the biggest global problems lie in the simplest, most unassuming of places. And it might even be your barber’s floor.

-Adyesha Singhdeo

References

https://www.sciencealert.com/could-human-hair-be-used-to-clean-up-oil-spills

Donate Your Hair to Clean Up the Oil Spill

 

How Are Oil Spills Cleaned Up?

Cleaning oil spills with hair

Bringing innovative solutions to life.

 Hair clippings are a low-tech, yet remarkably effective method to tidy up oil spills In fact, a San Francisco-based environmental non-profit organisation, Matter of Trust, has collected donations of thousands of pounds of human hair to […]

via Cleaning up oil spills with hair — Science Everyday

Clearer water, cleaner air: the environmental effects of coronavirus (video) —

 

From crystal clear waters in the canals of Venice to dramatic falls in pollution levels in major cities, the coronavirus pandemic has had a number of positive effects on the environment as millions across the world are placed under lockdown. Video: France 24

via Clearer water, cleaner air: the environmental effects of coronavirus (video) —

Lake Mendocino invasive mussel species inspections now seven days a week — The Ukiah Daily Journal

The U.S. Army Corps of Engineers at Lake Mendocino announced it will now be conducting inspections seven days a week for invasive mussel species, with help from the Sonoma County Water Agency, an increase from the current weekend inspections. The inspections will start every day on Sunday, March 1, and the inspectors will be looking […]

via Lake Mendocino invasive mussel species inspections now seven days a week — The Ukiah Daily Journal

Sunrise, palm trees, buildings, boats. — Cool San Diego Sights!

This chilly January morning I enjoyed a brisk walk. I brought out my camera when it was light enough for good photographs. Come follow me from the County Administration Building north along San Diego Bay for a short distance. After returning back south, we’ll turn away from the water and head east on Ash Street, […]

via Sunrise, palm trees, buildings, boats. — Cool San Diego Sights!

Timeline of events surrounding 3M’s admission of illegal chemical release into Tennessee River — WHNT.com

DECATUR, Ala. – A series of interesting events happened before and after 3M disclosed it failed to obey federal law by releasing certain manufacturing chemicals or the waste of those chemicals into the Tennessee River. 3M sent that disclosure letter in April. WHNT News 19 was told just weeks before the EPA may have been at 3M’s plant in Decatur in mid-March. WHNT News 19 went through official channels at the EPA to find out if it happened. As of […]

via Timeline of events surrounding 3M’s admission of illegal chemical release into Tennessee River — WHNT.com

Lots Of Snow Still Present Across Colorado’s High Country — CBS Denver

SUMMIT COUNTY, Colo. (CBS4) – As we head into mid-July in Colorado, snow on the ground is still alive and kicking for some of the state’s higher terrain. A few high mountain spots in northern Colorado haven’t seen snow on the ground last this long into the summer in eight years — since 2011! With…

via Lots Of Snow Still Present Across Colorado’s High Country — CBS Denver

Disease-Carrying ‘Kissing Bug’ Has Made Its Way North, Including Pennsylvania, Delaware, CDC Warns — CBS Philly

Experts call the blood-sucking insect the “Kissing Bug” because it’s known to crawl around your mouth and eyes, biting as you sleep.

via Disease-Carrying ‘Kissing Bug’ Has Made Its Way North, Including Pennsylvania, Delaware, CDC Warns — CBS Philly

Evangelical Environmental Network: Restoring our National Parks should be a bipartisan effort — Red, Green, and Blue

House Natural Resources Committee Chairman Rob Bishop (R-Utah) and Committee Ranking Member Raúl Grijalva (D-Ariz.) recently introduced the “Restore Our Parks and Public Lands Act”, a bipartisan effort to address the deferred maintenance backlog in our parks by establishing the National Park Service and Public Lands Restoration Fund. We applaud this bipartisan effort to address the critical maintenance […]

via Evangelical Environmental Network: Restoring our National Parks should be a bipartisan effort — Red, Green, and Blue

Why Straws Suck in More Ways Than One

This NBC article focused just on how much straws suck. They are killing the oceans because they are single-use non-recyclable plastic. The author goes to point out how some counties have even placed a ban on plastic straws all together. It really pushes the idea of the threes less rule: less consumption, less waste, less […]

via Why Straws Suck in More Ways Than One — the IDspiration

America’s Secret Ice Base Won’t Stay Frozen Forever 13m ago

(Source: www.wired.com)

This story originally appeared on Atlas Obscura and is part of the Climate Desk collaboration.

The creation of Camp Century, from the outset, was an audacious scheme. Under the thick ice of Greenland, a scant 800 miles from the North Pole, the US military built a hidden base of ice tunnels, imagined as an extensive network of railway tracks, stretching over 2,500 miles, that would keep 600 nuclear missiles buried under the ice. Construction began in 1959, under cover of a scientific research project, and soon a small installation, powered by a nuclear reactor, nested in the ice sheet.

In the midst of the Cold War, Greenland seemed like a strategic point for the US to stage weapons, ready to attack the USSR. The thick ice sheet, military planners imagined, would provide permanent protection for the base. But after the first tunnels were built, the military discovered that the ice sheet was not as stable as it needed to be: It moved and shifted, destabilizing the tunnels. Within a decade, Camp Century was abandoned.

When siting the secret ice base, the military chose a spot where dry snow kept the surface of Greenland’s ice sheet from melting, and when the base was abandoned its creators expected the remains to stay encased in ice forever. But decades later, conditions have changed, and as a team of researchers reported in a 2016 paper, published in Geophysical Research Letters, the now-melting ice sheet threatens to mobilize the dangerous pollutants left behind.

This hazard-in-waiting is a new kind of environmental threat: In the past, there was little reason to worry about water-borne pollution on an ice sheet 100,000 years old. As Jeff D. Colgan, a professor of political science at Brown University, writes in an article released last week in the journal Global Environmental Politics, Camp Century represents both a second-order environmental threat from climate change and a new path to political conflict.

“We’re starting to get better about dealing with the anticipated problems associated with climate change,” says Colgan. “There are going to be a whole host of unanticipated problems that we never saw coming.”

By the time the base was abandoned in 1967, it had its own library and theater, an infirmary, kitchen and mess hall, a chapel, and two power plants (one nuclear, one run on diesel). When the base closed, key parts of the nuclear power plant were removed, but most of the base’s infrastructure was left behind—the buildings, the railways, the sewage, the diesel fuel, and the low-level radioactive waste. In the 2016 paper, which Colgan worked on as well, the researchers suggested that the radiological waste was less worrisome than the more extensive chemical waste, from diesel fuel and polychlorinated biphenyls (PCBs) used to insulate fluids and paints.

Overall, the researchers estimated that 20,000 liters of chemical waste remain at the Camp Century site, along with 24 million liters of “biological waste associated with untreated sewage.” That’s just at Camp Century; the military closed down bases at three other sites in Greenland, too, and it’s unclear how much waste is left there. Over the next few decades, the researchers found, melt water from the ice sheets could mobilize these pollutants, exposing both the wildlife and humans living in Greenland.

Creating these ice-bound military bases required a delicate political negotiation to begin with. The US established its bases in Greenland under agreement with Denmark, which governed the island at the time. (Greenland now has self-rule but is still part of the Kingdom of Denmark.) There were some principles outlined about the two governments’ responsibilities for the bases, but, as Colgan writes in the new paper, the status of American nuclear weapons on Greenland fell into a diplomatic gray area.

The Danish government had taken a stand against nuclear weapons and would never condone a nuclear base on Greenland. But in 1957, an American ambassador, Val Peterson, made an official overture to the Danish prime minister, H.C. Hansen. If—just say—the US had nuclear weapons in Greenland, would the Danish government want to know? Five days later, the prime minister had a response: “I do not think that your remarks give rise to any comments from my side,” he wrote, in a “informal, personal, top secret” paper. The US went ahead with the plan.

There was similar ambiguity around the responsibility for the physical assets of the base. While they remained the property of the United States, the agreement said they could be “disposed of” in Greenland, after input from the Danish government. But it’s not at all clear who’s responsible for dealing with a long-term environmental hazard posed by the waste abandoned there.

This problem—who will pay to clean up environmental waste—is a common one; in the US, the Superfund program assigns responsibility for a polluted site, often across multiple parties associated with it over the years. But in this sort of international agreement between two governments, there’s no parallel process for divvying up blame or costs.

“These agreements are rarely fully specified in what’s written down on paper. There’s no real procedure for addressing disputes,” says Colgan. “If Denmark says, US, you’re responsible, and the US says, no, you’re responsible—we don’t have a good resolution process for that. Climate change is likely to make that kind of problem a lot more common.”

Already, a Greenland politician, who was serving as foreign minister, has lost his job over this issue. After the 2016 paper came out, he started pushing for the US and Denmark to take responsibility for these military hazards; his boss thought he took too aggressive a stance.

But the problem isn’t going to go away, and Colgan emphasizes that these second-order environmental consequences of climate change—which he calls “knock-on effects”—are only going to become more common, creating knotty political disputes. Think, for instance, of the chemical and oil refineries that, damaged by Hurricane Harvey, started dumping waste.

Many of these environmental hazards, though, can be linked to multiple causes; in Greenland, it’s easier to pinpoint the precipitating issue.

“What’s helpful about Camp Century is that, because it’s so isolated, we can be really clear that what’s causing the problem is climate change,” says Colgan. In the 1960s, there was little reason for the US military to imagine that their secret ice-base would cause environmental problems decades in the future. After all, it was encased in ice and should only have been buried deeper into the frozen surface over time.

More Info: www.wired.com

Photos: The 2017 supermoon as seen from around the world — Q13 FOX News

Stargazers, astronomers and curious sky-watchers are getting chance to witness the first and only full-moon supermoon of 2017. On Sunday night, the moon was 16% brighter and appeared 7% larger than its usual size. Last year, a memorable supermoon was marked in the history books. In November 2016, the moon was closest to the Earth…

via Photos: The 2017 supermoon as seen from around the world — Q13 FOX News

The E.P.A.’s Top 10 Toxic Threats

The Environmental Protection Agency has published a list of 10 toxic threats it will evaluate first under a law passed last year intended to crack down on hazardous chemicals. They are among 90 chemicals identified by the agency that may harm children, damage nerve tissue, cause cancer, contaminate the environment, accumulate in the bloodstream or show up in consumer products. As the review begins, industry and other interest groups are urging the E.P.A. to limit any restrictions.

Asbestos

Where you may find itAsbestos has not been manufactured in the United States since 2002, but imports surged last year, and it is still used in certain vehicle braking systems, asphalt roof coatings and gaskets. Asbestos is also commonly used by chlorine manufacturers.

How it could hurt you: Asbestos is associated with lung cancer and mesothelioma, a rare form of cancer that is found in the thin lining of the lung, heart, chest and abdomen.

Industry intervention: The trade group representing the chlorine industry, the American Chemistry Council, argues that “the few remaining uses for asbestos are tightly controlled,” and that banning it would not do much to protect health.

1-Bromopropane

The geologists Brenda Buck, left, and Rodney Metcalf have found asbestos on rocks and soil near Las Vegas.CreditIsaac Brekken for The New York Times

Where you may find it1-bromopropane is used as a refrigerant, a lubricant, a degreaser and a solvent in spray adhesives and dry cleaning. Its use in agricultural chemical manufacturing and foam-cushion manufacturing has also been reported.

How it could hurt you: Exposure can cause dizziness, headaches, slurred speech, confusion, muscle twitching, difficulty walking and loss of consciousness. Studies on animals suggest that exposure is also associated with reduced blood cell counts along with toxicity to the liver and the reproductive and nervous systems.

Industry intervention: The Alkylphenols & Ethoxylates Research Council, which represents companies that manufacture the chemical, arguethat the E.P.A. should not consider health threats that occur when people do not follow warning labels.

Carbon Tetrachloride

Where you may find it: Carbon tetrachloride, a clear liquid with a sweet smell, was once used in refrigeration fluids, aerosol propellants, pesticides, cleaning fluids, spot removers and degreasing agents. Most of those uses have been banned, but it is still has industrial applications, such as manufacturing petrochemicals.

How it could hurt you: It can cause injuries to the liver and kidneys and, at high levels, can result in fatal damage to the brain and nervous system.

Industry intervention: Halogenated Solvents Industry Alliance arguesthat worker exposures are already regulated by Labor Department safety rules and that “occupational conditions of use do not pose an unreasonable risk.”

1,4-Dioxane

Where you may find it: 1,4-dioxane is a flammable liquid with a variety of industrial applications, such as the manufacture of adhesives and sealants and other chemicals. It is used in paint strippers, dyes, greases, varnishes and waxes, and it can be found in antifreeze, aircraft de-icing fluids, deodorants, shampoos and cosmetics.

How it could hurt you: The E.P.A. says that the chemical is “likely to be carcinogenic to humans” and that it may cause kidney and liver damage. It is now often found at low levels in drinking water supplies.

Industry interventionThe American Cleaning Institute argues that while many consumer products may have small amounts of 1,4-dioxane, they are “extraordinarily low levels” and should be ignored.

Cyclic Aliphatic Bromide Cluster

Where you may find it: Cyclic aliphatic bromide cluster is a group of chemicals found in flame retardants, plastic additives and certain polystyrene foams used in the construction industry for thermal insulation boards.

How it could hurt you: People may be exposed to the chemicals from products and dust in the home. Animal test results suggest potential reproductive, developmental and neurological effects.

Industry intervention: The American Fuel & Petrochemical Manufacturers argues that the E.P.A. should not consider “potential of an accident or misuse, whether intentional or unintentional,” when deciding to restrict these chemicals, as “misuse is not even predictable and should never be included in toxicological risk assessment.”

Methylene Chloride

Where you may find it:Methylene chloride is used in pharmaceutical manufacturing and polyurethane foam manufacturing. It is also found in paint strippers, adhesives, metal cleaners and aerosol solvents. Many products are sold at home improvement stores.

How it could hurt you:Exposure can harm the central nervous system, with effects including dizziness, incapacitation and, sometimes, death. It is also linked to liver toxicity, liver cancer and lung cancer. It has been associated with dozens of deaths. The E.P.A., just days before the end of the Obama administration, proposed banning its use as a paint stripper because of these hazards.

Industry intervention: W.M. Barr & Company, the largest national manufacturer of solvents, removers, fuels and cleaning products, asked the E.P.A. to withdraw its proposed rule to ban methylene chloride in paint strippers, arguing that its products do “not present an unreasonable risk.”

N-Methylpyrrolidone

Where you may find it: N-Methylpyrrolidone is a solvent used in petrochemical processing. It can be found in plastics, paints, inks, enamels, electronics, industrial and consumer cleaning products and arts and crafts materials.

How it could hurt you: It may pose a particular risk to women who are pregnant or of childbearing age, according to studies on animals that suggest delayed fetal development.

Industry intervention: The NMP Manufacturers Group argues that the chemical “is used in many industry sectors, in varied processes,” and that it would be “unworkable for industry and unworkable for EPA” to evaluate them all.

Perchloroethylene

Where you may find it: Perchloroethylene, also known as perc, is a solvent widely used in dry-cleaning chemicals, automotive-care products, cleaning and furniture-care products, lubricants, greases, adhesives, sealants and paints and coatings.

How it could hurt you: High-level inhalation exposure is associated with kidney dysfunction, dizziness, headache, sleepiness and unconsciousness, while long-term inhalation exposure may affect the liver, the kidneys and the immune and reproductive systems. The E.P.A. has classified it as likely to be carcinogenic to humans, as it is associated with bladder cancer, non-Hodgkin lymphoma and multiple myeloma. It is also a drinking-water contaminant.

Industry intervention: The Drycleaning and Laundry Institute and the National Cleaners Association argue that “any future decision to reduce or phase out the use of perc in drycleaning will put an oppressive burden on thousands of cleaners” and that “sadly, in taking any radical regulatory action the EPA will be doing little to reduce the negligible risks associated with the use, while threatening the future viability of thousands of dry cleaners.”

Pigment Violet 29

Where you may find it: Pigment Violet 29 is used in watercolors, acrylic paints, automotive paints, inks for printing and packaging, cleaning and washing agents, pharmaceuticals, solar cells, paper, sporting goods and industrial carpeting. It is also approved to be used in food packaging.

How it could hurt you: There are limited health studies, but preliminary work suggests “acute toxicity, eye irritation, skin irritation, skin sensitization,” and perhaps reproductive and developmental toxicity.

Industry intervention: Color Pigments Manufacturers Association argues that it “does not pose any known hazard in any reasonably foreseeable use or misuse, and therefore cannot present an unreasonable risk.”

Trichloroethylene

Where you may find it: Trichloroethylene, also known as TCE, is used to make a refrigerant chemical and remove grease from metal parts. It is also a spotting agent for dry cleaning and can be found in consumer products. The E.P.A., in the final days of the Obama administration, proposed a ban on its use in dry-cleaning chemicals, spot removers and aerosol degreasers.

How it could hurt you: It is associated with cancers of the liver, kidneys and blood. Animal studies suggest that it may also be a factor in birth defects, testicular cancer, leukemia, lymphomas and lung tumors. TCE is also a drinking-water contaminant.

Industry intervention: The Halogenated Solvents Industry Alliance, which manufactures the chemical, argues that the E.P.A. has conducted a “very deficient risk assessment.” Pointing to one study the E.P.A. has used, the group says that “a single flawed study should not be the basis for the toxicological value that serves as the basis for regulation.”