Air pollution 'pandemic' shortens lives by 3 years: study
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It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
China has constructed the world’s largest experimental air-purifying tower
By Elizabeth Xu — Published January 21, 2024
In 2016, researchers in Xi’an, China — a city long plagued by air pollution — constructed the world’s largest experimental air-purifying tower. The researchers, from the Institute of Earth Environment at the Chinese Academy of Sciences, found that the surrounding area of over three square miles has improved in air quality.
Data collected in the vicinity of the experimental tower shows that this kind of tower presents promising solutions for cities contending with the escalating air pollution crisis. If similar initiatives were implemented globally, their impact could extend beyond individual cities, resulting in significant benefits for public health.
Air quality: The current landscape
Awareness of air pollution’s detrimental effects dates back several decades, when the US government was one of the first countries to introduce legislation to reduce air pollution: the Air Pollution Control Act, signed in 1955, provided funding for air pollution research. The enactment of the 1970 US Clean Air Act allowed regulators to limit emissions from both industrial sources and transportation, leading to efforts to reduce air pollution emissions, such as investments in the development of cleaner, less carbon-intensive technologies.
Despite increased awareness of air pollution, data reveals that hardly any place on Earth is spared from unhealthy air conditions. A study published in The Lancet Planetary Health journal found that only approximately 0.2 per cent of global land has been exposed to fine particulate matter — any particles that are 2.5 microns or smaller in diameter, also known as PM2.5 — at concentrations lower than the World Health Organization’s (WHO) recommended annual limit of five micrograms per cubic metre.
This means that more than 99 per cent of global land is exposed to dangerous concentrations of fine particulate matter, which originates as a byproduct of industrial combustion and poses a significant threat to human health due to its ability to be inhaled deep into the lungs.
A 2022 WHO report looked at findings from over 6,000 cities across 117 countries that are monitoring air quality. About 99 per cent of the global population breathes air that’s over WHO’s quality limits, with the most significant impacts on low and middle-income countries.
WHO’s data from 2019 showed that regions with high industrial activity, like areas in southern and eastern Asia, face a heightened risk of air quality issues. In some of these places, air quality is over WHO’s daily limit — 15 micrograms of gaseous pollutants per cubic metre — for over 90 per cent of the year. This leaves the majority of the global population vulnerable to the health risks associated with chronic exposure to air pollution, such as lung cancer and heart diseases, resulting in 6.7 million premature deaths worldwide.
How does the giant air filter work?
Standing at over 100 metres tall — and costing the Shaanxi provincial government roughly 2.69 million CAD to build — Xi’an’s air-purifying tower produces clean air at a rate of about eight cubic metres per second. The tower operates using solar energy that traps solar heat in the tower, which heats up polluted air drawn in through the tower’s base in an effect similar to the greenhouse effect. This heated air then rises through the filters within the tower.
Since its activation, the tower has cleansed more than 10 million cubic metres of air daily, significantly enhancing the air quality in its vicinity. Plans are underway to construct more towers across China in areas with unhealthy air quality levels, including Guangzhou, Hebei, and Henan.
To assess the impact of these experimental air purifiers, Xi’an placed over a dozen pollution monitoring stations across a 10-square-kilometre area around the tower. In just a few months, preliminary results found a 15 per cent reduction in PM2.5 levels during episodes of heavy pollution.
With promising preliminary results and expansion plans to introduce these projects to more Chinese cities, other countries are taking note. Kurin Systems, an air purification company based in India, was inspired by the giant air purifier tower in Xi’an and intends to install a 12-metre purification tower in New Delhi, long plagued with poor air as one of the world’s most polluted cities, with hopes to purify 1,130 cubic metres of air per day within an area of about five square kilometres.
Limitations and concerns for giant air purifiers
While large air filter towers hold potential for providing clean air to surrounding communities, their capacity remains local. Cao Junji, a chemist at the Chinese Academy of Sciences’ Key Laboratory of Aerosol Chemistry and Physics in Xi’an, proposed building up to half a dozen purifying towers around the city to significantly reduce air pollution. Furthermore, these air purifiers cannot replace indoor air filtration systems for buildings in highly polluted areas, such as factories and airports. In such cases, air purifiers and air filters remain the best solution for safe indoor air quality.
Critics argue that without more data regarding the power consumption for these filtration towers, the energy input required for operating these giant air purifiers seems like they might not be the best use of energy. Redirecting the same amount of power to generate clean electricity or reducing pollution at the source could also significantly reduce pollution. Other scientists worry that these towers may not effectively filter toxins that can be precursors to harmful particulate matter or liquids capable of penetrating the lungs and causing health problems, such as sulphur dioxide gas or secondary gaseous pollutants like ozone.
Nevertheless, giant air cleaners offer hope in areas where air quality is a major concern. While they may have limits and cannot single-handedly purify the air for entire cities, they serve as a valuable resource for improving air quality in regions of dangerous air quality levels where the reduction of air pollution is very difficult. They can potentially provide a temporary solution as scientists and policymakers work on strategies to reduce air pollution at its source.
Air pollution particles trigger cellular defense mechanisms
New research from the Keck School of Medicine of USC shows that air pollution particles activate a cellular defense mechanism known as autophagy, which may reduce the ability of cells to fight off other harms.
Peer-Reviewed PublicationKECK SCHOOL OF MEDICINE OF USC
The link between air pollution and lung disease has long been recognized. Now a new USC study reveals one biological process that may be behind that link — a discovery which could provide new insights on better ways to treat or prevent diseases related to pollution exposure.
"We know that diseases, especially lung diseases, can result from air pollution exposure. What we don't know are the mechanisms by which that occurs," said Edward Crandall, PhD, MD, professor of pathology, member of the Hastings Center for Pulmonary Research and director of the Will Rogers Institute Pulmonary Research Center at the Keck School of Medicine of USC.
In their research, Crandall and his team discovered a key step along the path between air pollution exposure and disease. Exposure to ambient nanoparticles, or very small pollutants in the air, limits the ability of cells to defend themselves against other potential harms. The findings were published in the journal Autophagy Reports.
Crandall, the study's senior author, and his colleagues studied a cellular defense process known as autophagy, which cells use to destroy damaged or abnormal internal materials. For the first time, the researchers found that, when exposed to nanoparticles, autophagy activity in cells seems to reach an upper threshold.
"The implication of these studies is that autophagy is a defense mechanism that has an upper limit, beyond which it can't defend the cell any further," Crandall said.
An upper threshold
The researchers conducted a series of tests using lung adenocarcinoma cells. They first exposed the cells to nanoparticles, then to rapamycin (a chemical known to stimulate autophagy), then to both nanoparticles and rapamycin. In every case, autophagy activity reached the same upper threshold and did not increase further.
Consequently, cells may lack the ability to further boost autophagy to defend against other dangers, such as smoke inhalation or a viral or bacterial infection. This may help explain why air pollution increases a person's risk for a number of acute and chronic lung diseases, including lung cancer, interstitial pulmonary fibrosis, and chronic obstructive pulmonary disease.
As part of the research, Crandall and his team also developed a new method of studying autophagy, which can support future studies on the subject. They used a combination of fluorescent dyes and a powerful imaging method, known as confocal microscopy, to document the amount of autophagy taking place inside individual cells.
"What's special is that we can now measure the autophagic activity of single living cells in real time. It's a novel method for studying autophagy," said Arnold Sipos, MD, PhD, assistant professor of research pathology at the Keck School of Medicine and the study's first author.
More research on autophagy
The new findings can help support ongoing research on autophagy, including for cancer treatment. While autophagy is a boon for healthy cells, it makes cancer cells harder to destroy. Developing methods to raise or lower autophagy in cells could be a key way to protect against and treat disease.
"The more we know about the mechanisms by which diseases occur, the more opportunity we have to find places in the pathway where we can intervene and prevent or treat the disease," Crandall said.
Next, Crandall, Sipos and their colleagues will conduct further research to test whether adding nanoparticles to a cell directly increases its vulnerability to other threats, such as an infection. They plan to study the link in both healthy cells and cancer cells.
About this study
In addition to Crandall and Sipos, the study's other authors are Kwang-Jin Kim of the Department of Pathology, Keck School of Medicine of USC and the Department of Biomedical Engineering, USC Viterbi School of Engineering and Constantinos Sioutas, Department of Civil and Environmental Engineering, USC Viterbi School of Engineering.
This work was supported by the Will Rogers Motion Picture Pioneers Foundation; Whittier Foundation; Hastings Foundation; and the National Institutes of Health [R01ES017034, U01HL108364, P01AG055367].
Autophagy Reports
Experimental study
Cells
Kinetics of autophagic activity in nanoparticle-exposed lung adenocarcinoma
New study reveals the cost of air pollution for Utahns' health and pocketbooks
UNIVERSITY OF UTAH
Air pollution has been a problem in Utah since before the territory was officially recognized as a state. The mountain valleys of this high elevation region are particularly vulnerable to the buildup of air pollution from vehicles, household heating and power production. Together with high per-capita energy use, this has resulted in periods of poor air quality. However, with so many types of pollution and regional conditions, determining the overall effects of air pollution on Utah's health and economy has been a major challenge. A new study from 23 Utah-based researchers, including five from the University of Utah, sought to do just that.
The study estimated that air pollution shortens the life of the average Utahn by around 2 years. And pollution costs Utah's economy around $1.9 billion annually. But many state-level actions, such as increasing vehicle and building efficiency, could reduce air pollution by double-digit percentages while benefitting the economy, the researchers found.
The team used an approach called expert assessment, which combines all available research and experience from published and unpublished scientific studies. Combining expertise from public health, atmospheric science and economics, the researchers assessed what types of disease and economic harm could stem from Utah's air pollution. The study was published in the peer-reviewed journal Atmosphere in a special issue on air quality in Utah.
They estimated that air pollution in Utah causes between 2,500 and 8,000 premature deaths each year, decreasing the median life expectancy of Utahns by 1.1 to 3.6 years. This loss of life expectancy is distributed across most of the population, they found, rather than only affecting "sensitive groups." For example, 75% of Utahns may lose 1 year of life or more because of air pollution and 23% may lose 5 years or more.
This substantial health burden is caused by many illnesses and conditions that most people might not associate with air pollution. For example, exposure to particulates and other pollutants increases occurrence of heart and lung diseases, including congestive heart failure, heart attack, pneumonia, COPD and asthma. These conditions account for 62% of the pollution impact on health, according to this study. The remaining 38% of health effects are associated with stroke, cancer, reproductive harm to mothers and children, mental illness, behavioral dysfunction, immune disease, autism and other conditions--all exacerbated by exposure to dirty air.
On the economic side, the researchers estimated that the direct and indirect costs of air pollution cost Utahns around $1.9 billion dollars (in the range of $0.75-3.3 billion) annually. This economic damage results from direct effects such as healthcare expenses, damage to crops and lost earning potential, in addition to indirect costs such as loss of tourism, decreased growth and regulatory burdens.
"It was a real eye-opener to see quantitative estimates of how serious the health and economic costs of air pollution are for the people of Utah," said Isabella Errigo, lead author and a graduate student at Brigham Young University. "The consequences of dirty air can seem very abstract until you read the medical research connecting the quality of our environment to our personal health."
Even though the estimates of cost in this study are on the low end of national estimates, which range up to $9 billion a year for Utah, they are still much higher than figures commonly discussed in the legislature. For example, approximately $10 million was appropriated to clean Utah's air this year, representing only 0.1% to 0.5% of the costs of air pollution.
"Utahns understand that air pollution imposes large hidden costs on our communities which is why it's consistently ranked as a top concern," said Logan Mitchell, a research assistant professor at the U and a co-author of the study. "Thankfully, innovation has made clean energy technologies cost competitive on the market, without even considering those hidden costs. The coming energy transition will mean being good stewards of the environment will also protect our economy."
The mismatch between the size of the problem and the proposed solutions emphasizes one of the central findings from the study: cleaning the air could have immense health and economic benefits for Utah. The authors combined their estimates of cost with the air pollution goals from the recent Utah Roadmap to Clean Air, produced by the U's Kem C. Gardner Policy Institute. If Utah achieves the roadmap's pollution reduction targets, they estimate, Utah could save $500 million per year by 2030 and $1.1 billion per year by 2050.
"The payoff of reducing pollution would be huge in economic terms and the benefits would be incalculable in terms of human life and health," said senior author Ben Abbott, an assistant professor at BYU. "It's a question of choice. Are we going to settle for incremental progress in air quality or take advantage of this immense opportunity to improve the health of our communities and remove this enormous drag on our economy?"
"When I read these results, my thoughts immediately turn to my friends and family who live in Utah," said co-author Rebecca Frei, a graduate student at the University of Alberta. "My grandmother goes walking and my niece plays on the playground every day. Changing some simple things about how we operate means added years of life. To me, that's a no-brainer. This isn't about pushing an agenda, this is about assessing the evidence and acting out of love for our families and community."
The researchers ranked more than 30 recommendations of how to best reduce the amount of air pollution in Utah. At the top of the list: increase efficiency of vehicles and buildings, invest in awareness, remove subsidies for nonrenewable energy, require payment for pollution and expand alternative transportation. They estimated that each of these interventions could result in double-digit decreases in air pollution. The researchers suggested that changes at the state level and community level as the most effective and tractable.
The researchers cautioned that no single change would achieve the desired improvement in air quality alone. "We need long-term implementation of proven pollution control measures," Errigo said. "It's going to take commitment from multiple groups at city to state levels to clean up our air and prepare for future growth."
The findings of this study are directly in line with the recommendations of the Utah Road Map to Clean Air and add quantitative estimates of the health and economic costs. The researchers hope that these estimates provide additional context for state legislators and concerned citizens who want to enact positive change.
"In our efforts to clear the air there are no perfect answers, but there are practical solutions," said Thom Carter, Executive Director of the Utah Clean Air Partnership (UCAIR) and co-author on the study. "When looking at how poor air quality impacts our region, it is important to know that we are making progress and that each person, family, organization, and community can find ways to reduce emissions and improve our quality of life."
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Find the full study here.
Other co-authors include Daniel Mendoza, Kerry Kelly, Andrew Freeman and Heather Holmes from the U; Sayedeh Sara Sayedi, Jeffrey Glenn, John D. Beard, Samuel Bratsman, Robert A. Chaney, Mitchell Greenhalgh, James D. Johnston, Leslie Lange and Audrey Stacey from BYU; Peter D. Howe, Randal Martin and Trang Tran from Utah State University; Andrew Follett from Yale Law School and Derrek Wilson from the University of Colorado, Boulder Law School.
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