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Barley plastic

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The durability, malleability, and low cost of plastics have made them ubiquitous.  Plastics are everywhere:  in packaging, clothing, and an endless variety of products.  As a result, they are everywhere in the environment and they tend to stay there, contaminating land and sea.  They are tough to recycle, and their production emits more carbon dioxide than all air traffic combined.  The search for viable substitutes for plastic is global and intensive.

Most common bioplastics are not an ideal solution.  They don’t break down that easily when tossed into the natural environment.  The process can take years. 

Researchers at the University of Copenhagen have invented a new material made from modified starch that can completely decompose in nature and can do so in only two months.  The material is made using natural plant material from crops and could be used for food packaging as well as many other things.

The new material is a biocomposite composed of several substances that decompose naturally.  The main ingredients are amylose and cellulose, common in many plants.  Amylose is extracted from crops like corn, potatoes, wheat, and barley.

The Danish researchers have developed a barley variety that produces pure amylose in its kernels.  Pure amylose is ideal because it is less likely to turn into a paste when it interacts with water. 

Combining the amylose with cellulose forms long, strong molecular chains, resulting in a durable, flexible material that can replace plastic in many applications.  The research team has founded a spinoff company and have applied for a patent for the new material.  It is unclear when the biofriendly barley-based plastic might be commercialized, but its potential is quite good.

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Researchers invent one hundred percent biodegradable “barley plastic”

Photo, posted May 20, 2010, courtesy of Frederick Lang Jr. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic food packaging

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Reducing the use of plastic is an important environmental goal.  Plastic is made from fossil fuels and plastic pollutes the land and the oceans.  It is estimated that 40% of plastic waste comes from packaging.  Plastic packaging is extremely common in the supermarket and there is a growing desire to reduce its use.  But it isn’t that easy.

Plastic packaging works well to slow the decay of vegetables and fruit.  Its use results in less produce being tossed into the garbage, where it creates almost 60% of landfill methane emissions.  In fact, food is the most common material in landfills.  The average American family of four spends $1,500 a year on food that ends up uneaten and nearly half of all household food waste is fruits and vegetables.

Products like bagged salads, berries in plastic clamshells, and plastic sealed potatoes and cucumbers are popular with shoppers because they stay fresh longer.  They are popular with grocers because the items don’t have to be weighed.  But all these things result in plastic waste.  It is a tradeoff that is difficult to make between food quality and safety vs. the environmental harm caused by plastic.

There are a variety of alternatives to plastic packaging of food that are being explored.  They range from biodegradable, organic coatings that can take the place of plastic films, to cardboard and paper produce packaging. 

But practically, there is yet no affordable and biodegradable plastic alternative that keeps fruits and vegetables safe and fresh.  Solving the food packaging problem is not easy.

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So Much Produce Comes in Plastic. Is There a Better Way?

Photo, posted July 1, 2007, courtesy of Brian via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sodium-ion batteries

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The transition away from fossil fuels is driving a rapidly increasing need for batteries.  Both electric vehicles and energy storage for the electric grid are enormous consumers of batteries.  At present, lithium-ion batteries are almost universally used for these purposes.  They have been getting better all the time and cheaper all the time and are likely to be the answer for the foreseeable future.  But they are not perfect.

Lithium is only found in a relatively small number of places and mining and extracting it is fairly expensive and environmentally unfriendly.  Lithium-ion batteries also frequently contain cobalt, which has its own set of problems.  There are also safety issues related to the flammability of lithium-ion batteries. 

As a result, there continue to be numerous efforts to identify and develop alternative battery technologies.  One of these is sodium-ion batteries, which are similar in many ways to lithium-ion batteries but in which sodium replaces lithium as the cathode material.

Sodium is extremely common – it’s found in ordinary salt – and sodium-ion batteries have a high energy density and are easy to produce.  They should have a long lifetime and have a more benign environmental impact than lithium-ion.  Many companies and researchers are working on sodium-ion batteries and are making good progress.

A study by Chalmers University in Sweden looked at the potential for sodium-ion batteries and found that the batteries are particularly promising for use in energy storage even in their current state of development and could eventually be used in cars.  Whether sodium-ion batteries can be good enough and cheap enough quickly enough to give lithium-ion a run for its money remains to be seen.

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Resource-efficient and climate-friendly with sodium-ion batteries

Photo, posted March 12, 2013, courtesy of Chris Hunkeler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A fern-based insecticide

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A spore-producing bacterium is the source of various crystal toxins (known as Cry proteins) that are widely used in modern agriculture to combat insect pests – generally caterpillars and other larvae – that attack important crops.  Pest control in corn, soybean, and cotton use these insecticidal proteins for protection against major insect pests.  The pesticides are obtained from Bacillus thringiensis (Bt) bacteria to produce the proteins.

Bt Cry proteins are secreted by the bacteria but are harmless to the bacteria.  They are harmless until ingested by insects and are then activated by the alkaline environment in the gut of insects which is entirely different from the acidic environment of our own digestive systems.  In the insect’s gut, the proteins become a powerful feeding inhibitor by breaking down the insect’s gut lining.  Bt Cry proteins are considered safe for humans.

Researchers continue to seek alternative solutions because there are concerns that insect pests could develop resistance to these toxic proteins.

Researchers from two Australian universities have analyzed the structure of a novel insecticidal protein that could be effective in protecting essential crops.  The protein is naturally produced by ferns including common houseplants like brake ferns.

The newly discovered proteins offer a different mode of action from the Cry proteins and therefore are a potential solution to the problem of pest resistance to existing insecticides.  The new family of insecticidal proteins is designated as iPD113 and has been shown to be very effective against caterpillar pests of corn and soybeans.

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Discovery: ferns produce crop-saving insecticide

Photo, posted October 5, 2015, courtesy of Marianne Serra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Paper Cups Are Not So Great | Earth Wise

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The environmental cost of plastic waste is a highly visible global issue.  The response has been a growing effort to replace plastic items with alternative materials.  One very visible change of this sort has been the replacement of plastic cups with paper cups at coffee shops.  But a new study at the University of Gothenburg in Sweden has found that this solution has problems of its own.

Researchers studied the effects of disposable cups in the environment on the larvae of the butterfly mosquito.  They placed disposable cups made from different materials in wet sediment and water for a few days and observed how the chemicals leached from the cups affected the growth of the larvae.  It turned out that all of the different kinds of cups had negative effects.  The concern is not specifically about mosquito larvae; it is the fact that more environmentally friendly drinking cups are still potentially harmful to living things.

Paper is neither fat nor water resistant, so paper cups need to be treated with a surface coating.  The most common coating is polylactide, which is a type of bioplastic.  It is generally considered to be biodegradable, but the study shows that it can still be toxic.  Bioplastics still contain many different chemicals and the potential toxicity of each of them is not well known.

The UN is trying to develop a binding agreement by the world’s countries to end the spread of plastics in society and nature.  For such an agreement to be effective, the plastics industry will need to clearly report what chemicals all products contain, including such mostly invisible products as the coating on paper drinking cups.

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Paper cups are just as toxic as plastic cups

Photo, posted October 23, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects On The Menu | Earth Wise

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According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity.  This constitutes a staggering rise of 200 million people compared to pre-pandemic levels.  Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.  

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity. 

Insects already form a significant part of diets in many cultures around the world.  Insects are great sources of nutrients, including protein, vitamins, and minerals.  But insects have yet to be embraced in any substantial way in western cultures… but that may be changing. 

In fact, the European Union has now certified four types of bugs as food fit for human consumption.  The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand.  Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction. 

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross.  But as the world population grows, the need for sustainable solutions in the food industry grows with it. 

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Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

It Really Is Greenhouse Gases | Earth Wise

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The scientific consensus that human-generated carbon dioxide is changing the climate began to form in the 1980s. 

For a long time, the changes to the climate were simply denied.  After a while, as those changes became increasingly hard to ignore, the argument shifted to the changes being real but not caused by anything people are doing.  The multi-trillion-dollar fossil fuel industry was strongly motivated to focus attention away from the association between carbon dioxide and climate change.

The greenhouse gas effect has been known since the 19th century.  It isn’t just real; it is essential to life on earth.  Without sufficient levels of carbon dioxide in the atmosphere to trap some of the sun’s heat, the earth would be an ice planet incapable of supporting much in the way of life.  But there can be too much of a good thing.

Naysayers continue to grasp at alternative explanations for the warming planet rather than the inconvenient truth.  Some people try to claim that it is the release of heat from all our energy-generating activities -power plants, heaters and air conditioners, vehicles, and so on – that is warming the planet.

That issue has been studied in detail.  Human activity does generate a lot of heat and, technically speaking, that heat does help warm the planet.  However, the sun dumps 10,000 times more heat on the earth than all of human energy production added together.  Just the normal fluctuations in solar energy are 10 times larger than everything we do put together.

What is increasingly warming the planet is not the continuing energy striking the earth; it is primarily the fact that growing levels of greenhouse gases in the atmosphere are trapping more and more of that heat and preventing it from escaping into space.

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Integrating anthropogenic heat flux with global climate models

Photo, posted August 25, 2009, courtesy of Gerald Simmons via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

El Paso’s Water Future | Earth Wise

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El Paso, Texas is part of the Paso del Norte region, which includes Ciudad Juarez in Mexico and Las Cruces, New Mexico.  The population on both sides of the border is booming, approaching 3 million people.  The region’s primary water source is the Rio Grande River.  But that river is declining.

Rising temperatures and decreasing rainfall have led to diminishing flow in the river.  Eighty percent of the river’s flow has historically been diverted to agriculture, but the reduced flow of the Rio Grande has forced many farmers to reduce planting or change to less water-hungry crops.  The river is expected to continue to decrease its flow as time goes by.

The city of El Paso gets 40% of its water supply directly from the Rio Grande.  Urban water authorities in the region are scrambling to find ways to provide cities with alternative supplies of water.

El Paso now gets some of its water from a desalination plant, which is the world’s largest inland municipal desalination plant.  The water comes from brackish groundwater rather than from the sea.  The briny waste from the plant is piped to an injection well many miles way and is permanently stored 4,000 feet underground.

El Paso continues to seek new water sources and reduce its water use.  It gets much of its water from wells drilled in nearby aquifers.  It is working to make this use of groundwater more sustainable.  The city recycles used residential water through its so-called purple pipe system, which cleans up waste water and delivers it for non-potable use on golf courses and park lawns. 

Like many places in the increasingly dry west, El Paso’s water future is uncertain. 

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As Rio Grande Shrinks, El Paso Plans for Uncertain Water Future

Photo, posted April 29, 2018, courtesy of R. Baire via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium Mining And Andes Ecosystems | Earth Wise

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A remote region in the high Andes straddling the borders between Argentina, Bolivia, and Chile has become known as the Lithium Triangle.   The area has become the focus of a global rush for lithium to make batteries for electric cars.  The global demand for lithium is expected to quadruple by 2030 to 2.6 million tons a year.

According to the U.S. Geological Survey, more than half of the world’s lithium reserves are dissolved in ancient underground water within the Lithium Triangle.  The cheapest way to extract the lithium is to pump the underground water to the surface and evaporate it in the sun to concentrate the lithium carbonate contained in it.

Every ton of lithium carbonate extracted using this cheap, low-tech method dissipates into the air about half a million gallons of water that is vital to the arid high Andes.  The process lowers water tables and has the potential to dry up lakes, wetlands, springs, and rivers.  Hydrologists and conservationists say the lithium rush in Argentina is likely to turn the region’s delicate ecosystems to deserts.

The global drive for green vehicles to fight climate change has the potential to be an ecological disaster in this remote region of South America and for the indigenous people who live there.

The environmental impacts are not an inevitable price for the transition to electric vehicles.  First of all, there are alternatives to lithium.  Both zinc and nickel are potential substitutes in rechargeable batteries.  But, there are also ways of obtaining lithium that are less destructive than evaporating the metal from saline ecosystems.  It is up to battery manufacturers, automakers, and financiers to start demanding lithium from sources that are less environmentally destructive.

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Why the Rush to Mine Lithium Could Dry Up the High Andes

Photo, posted September 25, 2015, courtesy of Nuno Luciano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plant-Based Foods And CO2 Emissions | Earth Wise

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We often hear how eating locally-sourced food is a way to minimize the carbon footprint of our diet.  But from a climate impact perspective, this only has a significant impact if transportation is responsible for a large portion of a food’s final carbon footprint.  In many cases, the greenhouse gas emissions related to transportation make up only a small portion of the total emissions from food, and what we eat is far more important.

In general, beef and lamb have the biggest climate footprint per gram of protein.  Plant-based foods tend to have the smallest impact. Pork and chicken are somewhere in the middle. 

According to new research, U.S. food production could reduce its agricultural carbon footprint between 2.5% and 13.5% by embracing plant-based alternatives to beef.  The study, from researchers at Cornell University, Johns Hopkins University, and international partners, found that most of the reduction would be achieved by decreasing the number of cows needed for beef production by two to twelve million animals.  The research was recently published in the journal Lancet Planetary Health.

However, the researchers also found that acting to reduce climate change in this manner could have unintended consequences.  For example, economic models from the research team show that the growth in popularity of plant-based beef could disrupt the agricultural workforce, threatening more than 1.5 million jobs. 

But in the big picture, doing nothing will cost much more than doing something to slow climate change.  Shifting diets away from meat and other animal products and towards more plant-based foods will help shrink carbon footprints and mitigate climate change.  It’s a win-win for the planet and for human health. 

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Plant-based ‘beef’ reduces CO2 but threatens ag jobs

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wireless EV Charging | Earth Wise

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Michigan, historically the focus of the American auto industry, has announced a new initiative to develop the nation’s first wireless charging infrastructure on a public road.  The Inductive Vehicle Charging Pilot is a partnership between the Michigan Department of Transportation and the Office of Future Mobility and Electrification.

The idea is to deploy an electrified roadway system that allows electric buses, shuttles, and vehicles to charge while driving, allowing them to operate continuously without stopping to charge.  In principle, such electrified roadways have the potential to accelerate the adoption of electric vehicles and turn public streets into safe and sustainable shared energy platforms.  This is especially valuable for drivers who might not have easy access to conventional charging facilities.

The pilot program is seeking proposals to design, fund, evaluate, iterate, test, and implement an inductive charging system along a one-mile stretch of state-operated roadway in Michigan.

The basic concept is to embed coils in a road that will convey electricity to cars outfitted with coils of their own.  It is much like the wireless charging pads used to power up smartphones.  Indiana is pursuing a similar project in the next couple of years.

Clearly driving through a one mile stretch of roadway for minute or two is not going to provide a whole lot of energy by whatever coupling mechanism is used. Scaling up the technology represents a significant challenge at the very least.  How practical such a scheme is from both a technology and an economic perspective remains to be seen.  In any case, it is interesting to see that states are looking at various alternatives for providing access to charging infrastructure to the growing population of electrified vehicles.

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Governor Whitmer Announces Initiative for Nation-Leading Wireless EV Charging Infrastructure in Michigan

Photo, posted September 6, 2020, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Could Take Over By 2035 | Earth Wise

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A study by UC Berkeley looked at the prospects for renewable energy sources to become the primary source of energy in the United States over the next 15 years.  Even though fossil fuels continue to fill that role at present, the plummeting costs of alternative energy sources – primarily solar and wind power – are making them increasingly attractive on the competitive market.

These cost reductions have occurred much faster than what was anticipated even just a few years ago.  According to the study, it is technically and economically feasible for renewable sources to provide 90% of our electricity by 2035.

The Berkeley researchers took the available data on renewable energy and created two scenarios for the next 15 years.  The first has energy policy remaining as it is now, without ambitious policy changes that encourage the growth of renewable energy.  In that scenario, they estimated that 55% of the US energy infrastructure would come from renewables.  That amount will not produce the change needed to meet Paris Climate Agreement goals but would simply come about because of the dramatically lower costs for renewable energy.

The second scenario includes state and federal governments leading the way to finance and facilitate the energy reform needed for a greener 2035.  It also relies on the large-scale use of grid-scale batteries to store the energy collected from solar and wind installations for when it is needed.

Which scenario is more realistic will depend on several major influential factors, notably the trajectory and consequences of the COVID-19 pandemic as well as the results of the November elections.   These things will have a huge impact on the future of our energy system.

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Report: By 2035, 90 Percent of the US Could Be Powered by Renewables

Photo, posted May 25, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Concrete Production And Diminishing Coal Burning | Earth Wise

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Coal burning is still one of the primary means of generating electricity in the United States, but its use is diminishing and doing so fairly rapidly.  The coal burning process produces residual, incombustible materials.  One of them is fly ash, which is composed of fine, glassy, rounded particles rich in silicon, aluminum, calcium, and iron oxides.  Fly ash is captured from coal plant flue gas by precipitators and bag filters. It turns out that two-thirds of this fly ash is not dumped into landfills or impoundments, but rather is put to use.

Because of its chemical and physical characteristics, fly ash can substitute for a portion of portland cement in concrete.  Using this byproduct material in making cement actually reduces its cost. Beyond cost, the addition of fly ash as a so-called supplementary cementitious material or SCM improves concrete’s long-term strength and reduces porosity and permeability.  It reduces the risk of thermal cracking and provides good long-term mechanical properties.

The amount of fly ash used in concrete products increased by 5% between 2011 and 2017 while the amount produced dropped by 36%.  Concrete production continues to increase steadily while fly ash production is steadily dropping.

Therefore, the concrete industry is looking for alternative sources of SCM.  The most obvious is the approximately 1/3 of fly ash that hasn’t been used to make concrete.  Much of that is landfilled or ponded onsite at power plants.  So, opportunities exist for excavating or dredging and recovering these materials.

As coal burning goes away, concrete manufacturing needs to make some changes.

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What Does the Changing Face of Electricity Production Mean for Concrete?

Photo, posted February 16, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat And Plastic Bottles

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In the middle of July, Americans along the East Coast and in the Midwest suffered through a massive heat wave that saw actual temperatures soaring and so-called feels-like temperatures go much higher.  The punishing heat had many of us reaching for those plastic water bottles all day long as we tried to keep hydrated.

Studies have shown that those single-use plastic bottles do not handle the heat very well.  Most plastic items release tiny amounts of chemicals into the beverages or food that they contain.   But the hotter it gets, the more the substances in plastic can move into food or drinking water.  As temperature and time increase, the chemical bonds in plastics increasingly break down and chemicals are more likely to leach.

A study at Arizona State University in 2008 looked at how heat sped up the release of the element antimony in bottles made of the common plastic PET.  Antimony is used to manufacture the plastic and can be toxic in high doses.  At mild temperatures, very little antimony is released.  But PET and other plastics can leach a variety of chemicals when exposed to higher temperatures.

According to the FDA, the amounts of chemicals released by plastics are too miniscule to cause health problems.  However, scientists are still looking at the long-term effects of using so much plastic.  The question is whether all those small doses can eventually add up to something not so harmless.  Given that we don’t really know the cumulative effect of being surrounded by plastics in the goods we buy as well as the presence of microplastics in our water, it seems like a good idea to try to limit our exposure when alternatives are available.

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Exposed to extreme heat, plastic bottles may ultimately become unsafe

Photo, posted June 7, 2013, courtesy of Tim Stahmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaning Up Shipping Fuel

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Cargo ships are significant sources of global air pollution because of their fuel oil.  Most ships burn something called “bunker fuel” which is a pitch-black, molasses-thick fuel made from the dregs of the oil refining process.  It is loaded with sulfur, so when it is burned it produces noxious gases and fine particles that can harm human health and the environment.  Because bunker fuel is made from petroleum refining residues, waste byproducts sometimes end up in the mix, making the stuff even a worse source of pollution.

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Septic Systems and Water Contaminants

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A recent study has shown that septic systems in the U.S. routinely discharge pharmaceuticals, consumer product chemicals and other potentially hazardous substances into the environment.   The comprehensive study, published in the journal Environmental Science & Technology, raises health concerns since these chemicals can end up in groundwater and drinking water supplies.

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A Climate-Friendlier Coolant

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Recently, negotiators from more than 170 countries reached a legally binding accord in Kigali, Rwanda to cut the use of hydroflurocarbons, or HFCs, which are chemical coolants used in air conditioners and refrigerators.  HFCs are just a small percentage of the greenhouse gases in the atmosphere, but they are supercharged greenhouse gases that have 1,000 times the heat-trapping potency of carbon dioxide.

[Read more…] about A Climate-Friendlier Coolant

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