Environmental Hazards, Science

Scientists Find New Way to Process Radioactive Waste

The question of what to do with radioactive waste may have been solved by a team of Japanese scientists.
The question of what to do with radioactive waste may have been solved by a team of Japanese scientists. Photo: Shutterstock

Ever since the first atomic bomb was exploded during World War II’s Manhattan Project, and ever since the first nuclear power plant opened in Obninsk, Russia, radioactive waste has been accumulating. As the number of nuclear power plants and nuclear weapon plants increased, the question of what to do with all that waste has become one of the biggest issues facing science today.

The primary issue is what to do with radioactive waste after the uranium and plutonium have been recovered from spent nuclear fuel using standard reprocessing methods such as Plutonium Uranium Redox Extraction (PUREX).

Up until now, the most viable option for disposal of nuclear waste has been burying it deep underground. Other solutions such as partitioning and transmuting, which involve separating nuclear fuel into minor actinides such as neptunium, americium, and curium, have proven to be costly and cumbersome because of the need to separate isotopes before they can undergo transmutation. But now, a team of researchers at Tokyo Institute of Technology may have come up with a solution to the radioactive waste problem.

The team discovered a method of dramatically reducing the effective half-life of long-lived fission products (LLFPs) such as selenium-79, zirconium-93, technetium-99, palladium-107, iodine-129, and caesium-135. That method involves transmuting these isotopes in fast-spectrum reactors, which don’t need isotope separation like other methods do.

By adding a moderator (slowing-down material) called Yttrium deuteride (YD2), the team found that LLFP transmutation efficiency increased in the radial blanket and shield regions of the reactor. The researchers say this increased effectiveness is due to the moderator’s ability “to soften the neutron spectrum leaking from the core.”

Using this method, the researchers say, the 17,000 tons of LLFPs in Japan could potentially be disposed of by using 10 fast spectrum reactors. This method also has the advantage of contributing to electricity generation and supporting efforts toward nuclear non-proliferation.

Although ultimately, the best solution to the nuclear waste problem is to invest in non-toxic energy sources like solar and wind power, it’s a good thing these researchers came up with a way to decrease the toxicity of radioactive waste and give its by-products a new life—and a much shorter half-life.

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Environmental Hazards, oceans

Keeping Plastic Out of Our Waters

Several nations and states are taking measures to prevent plastic pollution from reaching the oceans.
Plastic pollution in the ocean. Photo: Shutterstock

This past week Chile’s President Michelle Bachelet signed a bill that will ban plastic bags in more than 100 coastal areas. Her decision, she said, was about “taking care of our marine ecosystems.”

“Our fish are dying from plastics ingestion or strangulation; [limiting plastic bags] is a task in which everyone must collaborate,” she added.

It’s a huge deal, not only for Chile’s environment, but for other countries considering their own plastic bag ban.

Chile’s World Wildlife Fund noted that the bill “marks a very important milestone for Chile and opens the door for the whole country to say goodbye to plastic bags.”

According to a 2015 study published in Science, about eight million tons of plastic are dumped into the sea every year, which can affect millions of marine species. And toxins ingested by fish exposed to those plastics can affect humans as well when they eat those fish.

Chile’s potential ban on plastic bags isn’t the first such ban. The U.S. in particular has already instated bans in many areas, including Massachusetts, California, and Washington. They’ve been shown to be quite effective, too: The ban in San Jose, California led to an 89 percent reduction in plastic bags ending up in storm drains. And in Seattle, Washington, the plastic bag ban has led to a 50 percent reduction of plastic bags ending up in city dumps.

In other areas it’s been trickier. State Senator Linda Stewart of Orlando recently announced she will file a bill in Tallahassee to reverse the current law that prevents governments from banning plastic bags and Styrofoam containers.

Why would a city have such a law in place to begin with? Money, it seems: Grocery heavy-hitter Publix lobbied state politicians to the tune of $1 million to get the law against banning plastic bags instated. However, Stewart may be turning the (plastic) tides with her bill, if it’s passed. At the very least, it’s inspired a similar measure in the Florida House of Representatives.

Banning plastic bags in more places—both in the U.S. and elsewhere—is likely to be a huge boon to marine wildlife. But there’s still a lot of work to be done.

Environmental Hazards, Science

Road Pricing Could Be the Most Effective Solution to Car Pollution

A researcher from the University of British Columbia has concluded that road pricing is the most effective traffic management strategy for reducing urban pollution.
Photo via Pixabay

Motor vehicles are a huge source of pollution in cities. For many years, governments have used traffic management strategies to try and reduce vehicle emissions—but few seem to have made as much of a difference as road pricing.

Road pricing is essentially a “pay per use” plan that levies charges such as road tolls, congestion charges, and charges designed to discourage the use of certain types of vehicles or fuel sources in order to reduce pollution and congestion within city limits.

University of British Columbia transportation expert and civil engineering professor Alexander Bigazzi reviewed 65 studies on traffic management strategies in Asia, Europe, and the Americas. He concluded that road pricing is the most effective strategy to reduce emissions and traffic.

Other traffic management strategies include speed enforcement programs, lane management (e.g., HOV lanes), road and congestion pricing, and trip reduction strategies such as telecommuting or ride sharing.

“The strategies with the best evidence of air quality improvements are area road/congestion pricing and low-emission zones,” Bigazzi said. “Other strategies have potential benefits, but there is less empirical evidence, either because the benefits are very small or because the benefits are offset by some other effect.”

Why are road pricing and low-emission zones so effective? A major reason is that they reduce the amount of driving. They also ease congestion and reduce emission rates. Low-emission zones also encourage people to buy cleaner vehicles.

Of course, road pricing has to be implemented on a pretty large scale in order to be effective. Cities can’t just implement road pricing on certain roads, because motorists would find other ways to get into the city where they are not faced with road pricing or low-emission zones.

“Hundreds of cities in Europe have congestion pricing or low-emission zones in their city centers and are enjoying improved traffic flow and air quality,” Bigazzi said. “These strategies haven’t been embraced in North America in the same way for a variety of reasons, but there are great potential benefits for cities here ready to embrace innovation.”

What do you think? Would you like to see cities use traffic management strategies like road pricing in order to reduce pollution, even if it meant less convenience for you? Do you think road pricing would work in your city? Please share your thoughts in the comments!

Climate Change, Environmental Hazards, Nature, Science

Was Hurricane Harvey Caused by Global Warming? Not Entirely

Was Hurricane Harvey caused by global warming? Not entirely.
Cars submerged by flooding in the wake of Hurricane Harvey. Photo: michelmond / Shutterstock.com

Climate change is responsible for a lot of things, but it may not be directly responsible for Hurricane Harvey.

Harvey is not the first hurricane to hit the Texas coast.  A deadly hurricane struck Galveston in 1900, and that storm caused thousands to lose their lives, primarily due to the lack of warning. Meteorology was not an advanced science at that time, and there were no satellites to track the storms as they moved across the Atlantic Ocean.

However, climate change is almost certainly responsible for the epic rainfall and catastrophic flooding endured by the cities struck by Hurricane Harvey.

“This is they type of event, in terms of extreme rainfall, that we would expect to see more of in a warming climate,” Dr. Friederike Otto from the University of Oxford told the BBC.

In fact, the rainfall was so extreme that the National Weather Service had to add new colors to its rainfall maps to account for the intensity of Harvey’s rains.

There’s a physical law called the Clausius-Claperyon equation, which says that a hotter atmosphere holds more moisture. For every degree Celsius in warming, the atmosphere can hold 7 percent more water, which makes rainfall events more extreme.

The temperature of the seas also contributes to the strength of hurricanes.

“The waters of the Gulf of Mexico are about 1.5 degrees warmer than they were from 1980 to 2010,” Sir Brian Hoskins of the Grantham Institute for Climate Change told the BBC. “This is very significant because it means the potential for a stronger storm is there, and the contribution of global warming to the warmer waters in the Gulf, it’s almost inevitable that there was a contribution to that.”

Although there have been slow-moving storms over Texas in the past, some scientists still attribute the intensity of Harvey to climate change.

Professor Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research says that a general slowdown in atmospheric circulation in the earth’s middle latitudes could be a result of changing climate in other parts of the world.

“This is a consequence of the disproportionately strong warming in the Arctic,” Rahmstorf said. “It can make weather systems move less and stay longer in a given location—which can significantly enhance the impacts of rainfall extremes.”

Other scientists think it’s a stretch to believe that the slowly moving nature of the storm is caused by climate change. “I don’t think we should speculate on these more difficult and complex links like melting in the Arctic without looking into these effects in a dedicated study,” said Dr. Otto.

In addition to the damage caused by the flooding, pollution is causing the floodwaters to become a toxic stew of sewage, garbage, chemicals from more than 20 Superfund sites in the Houston area, oil and petrochemicals from damaged refineries, and much more, are causing concern.

“There’s no need to test [the water],” Houston Health Department spokesman Porfirio Villareal told the New York Times. “It’s contaminated. There’s millions of contaminants.”

Eco-friendly, Environmental Hazards, Science

Cigarette Butts Could Soon Be Turned Into Something Useful

A research team in Australia has come up with a way to turn cigarette butts into pavement.
Soon, these nasty things may be IN your asphalt, not ON it. Photo via Pixabay

How do you take the remains of a nasty habit and turn it into something that benefits everyone? Researchers at RMIT University in Melbourne, Australia, may have a solution.

Every year, trillions of cigarette butts are produced worldwide, and most of those are discarded into the environment. Loaded with toxins, they take a very long time to break down, and when they do, all their poisonous chemicals are released into waterways.

But the team at RMIT University, led by Dr. Abbas Mohajerani, has shown that cigarette butts can be mixed with asphalt and lead to a product that not only tolerates wear and tear of daily traffic but also reduces thermal conductivity.

What this means is that the disgusting remains that some inconsiderate smokers leave behind can solve a big waste problem and could help to reduce the urban heat island effect common in large cities.

“I have been trying for many years to find sustainable and practical methods for solving the problem of cigarette butt pollution,” said Mohajerani, a senior lecturer in RMIT’s school of engineering.

“In this research, we encapsulated the cigarette butts with bitumen and paraffin wax to lock in the chemicals and prevent any leaching from the asphalt concrete. The encapsulated cigarette butts were mixed with hot asphalt mix for making samples,” he added.

About 6 trillion cigarettes are produced each year, resulting in more than 1.2 million tons of cigarette butts. As the world’s population—and the number of smokers—continues to grow, these numbers are expected to increase by more than 50 percent by the year 2025.

“Encapsulated cigarette butts developed in this research will be a new construction material which can be used in different applications and lightweight composite products,” Mohajerani said. “The only ways to control [the chemicals in the cigarette waste] are either by effective encapsulation for the production of new lightweight aggregates or by the incorporation in fired clay bricks.”

How’s that for an unlikely solution to a big problem? I think this idea is pretty darn brilliant, and I’ll be curious to see how the research plays out in real-world applications.

Environmental Hazards, Nature

Invasive Carp Jumps Barrier to Great Lakes

A fisherman caught an invasive silver carp nine miles from the Great Lakes. Photo: Shutterstock

A live Asian carp has been caught 9 miles from Lake Michigan.

This is a big deal. These fish “are voracious eaters, able to consume 5 to 20 percent of their body weight each day, leaving far less of the microscopic plant and animal life (phytoplankton and zooplankton) to support native fisheries,” says Fisheries and Oceans Canada. They have been blamed for pushing out native species and lowering water quality.

There are four types of Asian carp that are considered a threat to the Great Lakes: bighead, silver, black, and grass.

Millions of dollars have been spent to construct an electrified barrier designed to keep the invasive carp from entering the Great Lakes. But this carp, weighing 8 pounds and measuring 28 inches long, got past that barrier. It was caught “with a gill net by a contracted commercial fisher,” the Asian Carp Regional Coordinating Committee said in a statement.

“The news of an Asian carp found within nine miles of the Great Lakes is cause for serious concern,” Ohio Republican Senator Rob Portman said in a statement. “The fishing industry in the Great Lakes is a $7 billion a year economic engine and it would be severely threatened if Asian Carp are allowed into the Great Lakes.”

This finding comes as the Trump administration considers cutting the Great Lakes Restoration Initiative, a $300 million-per-year program that helps states with environmental projects such as keeping invasive Asian carp out of the lakes.

“Asian carp are a very serious threat to our Great Lakes economy,” Michigan Democratic Senator Debbie Stabenow tweeted. “The Trump Admin must immediately release the study they have been blocking so we can permanently stop the Asian carp!”

“This is one more reason why we must fully fund the Great Lakes Restoration Initiative again. I have fought proposed cuts from both the previous administration and the new one and I will continue to lead efforts in this Congress to ensure this critical initiative is fully funded,” Portman said.

The Illinois department of natural resources and the Asian Carp Regional Coordinating Committee said, “It is important to note that this preliminary finding does not confirm that a reproducing population of Asian carp currently exists above the electric dispersal barriers or within the Great Lakes.”

Nonetheless, the group is launching “two additional weeks of intensive sampling in the area.”

Climate Change, Environmental Hazards

Climate Change Bringing Tropical Diseases to Higher Latitudes

Tropical diseases are spreading farther north as the climate continues to warm.
The Anopheles mosquito is responsible for the spread of malaria. Its range may be increasing due to climate change. Photo via Pixabay

It’s been known for a long time—like, since Roman times—that climate change brings disease. Roman aristocrats would move to summer homes in the mountains in order to avoid malaria-transmitting mosquitoes, for example.

But even the appearance of malaria mosquitoes was simply a summer phenomenon that was a regular part of south European climate. Nowadays, we have more to be worried about, thanks to global climate changes.

Tropical diseases like viral illness Chikungunya, West Nile Virus, and Zika; bacterial infection Vibrio vulnificus; and parasitic infection malaria are finding their way farther and farther north as greenhouse gases boost temperatures around the world.

The Asian tiger mosquito and yellow fever mosquitoes infect humans with Chikungunya. The virus had been limited to tropical regions of Africa, Asia, and South America, but as temperatures have warmed, the geographical distribution of these mosquitoes has grown. If climate change continues unchecked, a team at the University of Bayeruth warns, the virus could even spread to southern Europe and the United States.

“People have already been infected with Chikungunya in Italy, France, and Florida,” said Dr. Stephanie Thomas, a biogeography researcher at the University of Bayeruth. “However, such cases are still too rare to play any significant role in our model. The climactic potential for new diseases in southern Europe and the U.S. is probably being underestimated.”

Vibrio illnesses are caused by bacteria that occur naturally in warm ocean waters. Although Vibrio infections have been seen sporadically in warm seas from Texas to Maryland, Vibrio bacteria are spreading north. Vibrio illnesses have even appeared as far north as the Arctic Circle.

We are seeing lots of new hospitable areas opening up for these bacteria,” said Craig Baker-Austin, a Vibrio expert at the UK’s Centre for Environment, Fisheries, and Aquaculture Sciences laboratory in southern England. “Climate change is essentially driving this process, especially warming.”

In Europe, ticks that carry Lyme disease, that once only appeared in southern Europe, are now appearing as far north as Sweden. A region near Russia’s Ural Mountains has seen a 23-fold increase in tick-borne encephalitis over the past 20 years. The sand flies that host the parasite-borne illness leishmaniasis are showing up in north Texas.

“So often so many of the things we talk about with climate change are ‘this is going to be a problem in 2030 or 2050 or 2100, and it sounds so far away,” said Stanley Maloy, a microbiologist at San Diego State University. “But we’re talking about things where our one-degree centigrade change in temperature is already enough to affect infections. We have clear evidence in many cases things are happening already, and they’re tightly correlated to changes in ambient temperature, extreme weather, or water temperature.”

Regardless of whether people believe climate change is real, it’s inevitable that even the greatest skeptics will soon find themselves being affected by the spread of tropical diseases to higher latitudes.