The study was led by University of Technology Sydney (UTS) bioremediation researcher Associate Professor Fraser Torpy, in partnership with leading Australian plantscaping solutions company Ambius.

The researchers found that the Ambius small green wall, containing a mix of indoor plants, was highly effective at removing harmful, cancer-causing pollutants, with 97 per cent of the most toxic compounds removed from the surrounding air in just eight hours.

Poor indoor air quality is responsible for 6.7 million premature deaths globally, according to the World Health Organisation. Most people spend 90% of their time indoors at home, school or the workplace, so adopting new strategies to improve air quality is critical.

Ambius General Manager Johan Hodgson said the research presented new evidence into the critical role played by indoor plants and green walls in cleaning the air we breathe quickly and sustainably.

“We know that indoor air quality is often significantly more polluted than outdoor air, which in turn impacts mental and physical health. But the great news is this study has shown that something as simple as having plants indoors can make a huge difference,” Mr Hodgson said.

Previous studies on indoor plants have shown they can remove a broad range of indoor air contaminants, however this is the first study into the ability of plants to clean up gasoline vapors, which are one of the largest sources of toxic compounds in buildings worldwide.

Offices and residential apartment buildings often connect directly to parking garages, either by doors or elevator shafts, making it difficult to avoid harmful gasoline-related compounds seeping into work and residential areas. Many buildings are also exposed to gasoline fumes from nearby roads and highways.

Breathing gasoline fumes can lead to lung irritation, headaches and nausea, and has been linked to an increased risk of cancer, asthma and other chronic diseases from longer term exposure, contributing to decreased life expectancy.

Associate Professor Torpy said the study results, based on measurements from a sealed chamber, had far exceeded their expectations when it came to removing gasoline pollutants from the air.

“This is the first time plants have been tested for their ability to remove gasoline-related compounds, and the results are astounding.

“Not only can plants remove the majority of pollutants from the air in a matter of hours, they remove the most harmful gasoline-related pollutants from the air most efficiently, for example, known carcinogen benzene is digested at a faster rate than less harmful substances, like alcohols.

“We also found that the more concentrated the toxins in the air, the faster and more effective the plants became at removing the toxins, showing that plants adapt to the conditions they’re growing in,” Associate Professor Torpy said.

Mr Hodgson said the findings confirmed feedback they’d received after installing plants in hundreds of office buildings across the nation.

“At Ambius, we see over and over again the effects plants have in improving health, wellbeing, productivity and office attendance for the thousands of businesses we work with. This new research proves that plants should not just be seen as ‘nice to have’, but rather a crucial part of every workplace wellness plan.

“The bottom line is that the best, most cost effective and most sustainable way to combat harmful indoor air contaminants in your workplace and home is to introduce plants,” Mr Hodgson said.

Further information: https://www.ambiusindoorplants.com.au/ambius-capability/ambius-and-uts-research-study

“We found that coal can be this geological hydrogen battery,” said Shimin Liu, associate professor of energy and mineral engineering at Penn State. “You could inject and store the hydrogen energy and have it there when you need to use it.”

Hydrogen is a clean burning fuel and shows promise for use in the most energy intensive sectors of our economy — transportation, electricity generation and manufacturing. But much work remains to build a hydrogen infrastructure and make it an affordable and reliable energy source, the scientists said.

This includes developing a way to store hydrogen, which is currently expensive and inefficient. Geologic formations are an intriguing option, the scientists said, because they can store large amounts of hydrogen to meet the peaks and valleys as energy demand changes daily or seasonally.

“Coal is well-studied, and we have been commercially producing gas from coal for almost a half century,” Liu said. “We understand it. We have the infrastructure. I think coal would be the logical place to do geological hydrogen storage.”

To put this to the test, the scientists analyzed eight types of coals from coalfields across the United States to better understand their sorption and diffusion potential, or how much hydrogen they can hold.

All eight coals showed considerable sorption properties, with low-volatile bituminous coal from eastern Virgina and anthracite coal from eastern Pennsylvania performing the best in tests, the scientists reported in the journal Applied Energy.

“I think it’s highly possible that coal could be the very top selection for geological storage from a scientific perspective,” said Liu. “We find that coal outperforms other formations because it can hold more, it has existing infrastructure and is widely available across the country and near populated areas.”

Depleted coalbed methane reservoirs may be the best candidates. These seams contain unconventional natural gas like methane and have become an important source of fossil fuel energy over the last several decades. The methane sticks to the surface of the coal, in a process called adsorption.

Similarly, injecting hydrogen into coal would cause that gas to absorb or stick to the coal. These formations often have a layer of shale or mudstone on top that act as a seal keeping methane, or in this case hydrogen, sealed until it is needed and pumped back out, the scientists said.

“A lot of people define coal as a rock, but it’s really a polymer,” Liu said. “It has high carbon content with a lot of small pores that can store much more gas. So coal is like a sponge that can hold many more hydrogen molecules compared to other non-carbon materials.”

The scientists designed special equipment to conduct the experiments. Coal has a weaker affinity with hydrogen compared to other sorbing gases like methane and carbon dioxide, so traditional pressurized equipment for determining sorption would not have worked.

“We did a very novel and very challenging design,” Liu said. “It took years to figure out how to do this properly. We had to properly design an experiment system, trial and error based on our previous experience with coals and shales.”

Based on their results, the scientists determined anthracite and semi-anthracite coals are good candidates for hydrogen storage in depleted coal seams, and low-volatile bituminous coal are better candidates for gassy coal seams.

Developing hydrogen storage in coal mining communities could bring new economic opportunities to these regions while also helping create the nation’s hydrogen infrastructure.

“In the energy transition, it’s really coal communities that have been the most impacted economically,” Liu said. “This is certainly an opportunity to repurpose the coal region. They already have the expertise — the energy engineer and skills. If we can build an infrastructure and change their economic opportunities — I think that’s something we should consider.”

Future work will focus on the dynamic diffusivity and dynamic permeability of coal, features which determine how quickly hydrogen can be injected and pumped back out, the scientists said.

“I think Penn State is the right place to do all this research — we have the coal reserves, we have natural gas, we have both the engineering and economic expertise at the University,” Liu said. “This is the logical place to do this.”

Also contributing from Penn State was Ang Liu, instructor, John and Willie Leone Family Department of Energy and Mineral Engineering.

Researchers from the University of Tsukuba have developed and validated a model (“dynamic prospect theory”) that integrates the most popular model in behavioral economics to describe decision-making under uncertainty — prospect theory, and a well-established model of learning from neuroscience — reinforcement learning theory. This model more accurately described the decisions that people and monkeys made while facing risk than prospect theory or reinforcement learning theory alone.

Specifically, the researchers asked 70 people to repeatedly choose between two lotteries in which they could gain some reward with some probability. The lotteries varied in the size of the reward, the probability of receiving it, and the amount of risk involved. The results showed that immediately after experiencing an outcome that was bigger than the expected value of the selected option, participants behaved as if the probability of winning in the next lottery increased. Senior author of the study Assistant Professor Hiroshi Yamada says “This behavior is surprising because winning probabilities were clearly described to the participants (participants did not have to learn them from experience) and these probabilities were also completely independent of previous outcomes.” Using their dynamic prospect theory model, the researchers were able to determine that the change in behavior is driven by a change in the perception of probabilities rather than by a change in valuation of rewards.

Yamada also says: “Such learning from unexpected events underlies reinforcement learning theory and is a well-known algorithm that occurs when people need to learn the rewards from experience. It is interesting that it occurs even if learning is not necessary.”

In similar experiments with macaque monkeys, whose brains closely resemble those of humans, essentially the same results were observed. Researchers commented that the similarity in human and monkey behavior was remarkable in this study.

Based on the results of this research, it is expected that the investigation of the monkey brain will lead to an understanding of the brain mechanisms involved in the perception of rewards and probability that all of us use when making risky decisions, as well as the joy we feel when we succeed.

This study was supported by JSPS KAKENHI Grant Numbers JP:15H05374 and 21H02797, Takeda Science Foundation, Council for Addiction Behavior Studies, Narishige Neuroscience Research Foundation, Moonshot R&D JPMJMS2294 (H.Y.), and ARC DP190100489 (A.T.).