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nitrogen dioxide

Solutions for cleaner air

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Air pollution is a problem for most of the world’s cities.  Many cities in India and China continue to face major public health crises due to their polluted air.  American cities also don’t escape from polluted air.  Californian cities still struggle with smog despite decades of effort to reduce it.  But one major city that has waged a successful battle against air pollution is Paris, France.

Over the past 20 years, Paris has transformed its air by trading automobile roads for bike lanes, adding green spaces, and eliminating 50,000 parking spaces.

According to independent air quality tracking, levels of fine particulate matter in Paris have decreased 55% since 2005 and nitrogen dioxide levels have fallen 50%.  A combination of regulations and public policies including steps to limit traffic and ban the most polluting vehicles have produced these results. 

Despite pushback from various sources such as car owners’ associations, suburban commuters, and right-leaning politicians, Parisians have continued to pursue cleaner air policies.  In April, Parisians voted to turn an additional 500 streets over to pedestrians.  Last year, Paris sharply increased parking fees for SUVs, forcing drivers to pay three times more than they would for smaller cars. 

Ambitious policymaking can directly improve health in large cities.  As one former advisor to the city explains, the French capital has developed “an urban policy based on well-being.”

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Paris said au revoir to cars. Air pollution maps reveal a dramatic change.

Photo, posted June 3, 2018, courtesy of Francisco Anzola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Unhealthy Air | Earth Wise

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According to the World Health Organization, almost the entire global population – 99% in fact – breathes air that exceeds WHO air quality limits and threatens their health.

Air quality is of great concern everywhere.  Over 6,000 cities in 117 countries monitor air quality, but the people living in those cities are still breathing unhealthy levels of fine particulate matter and nitrogen dioxide. The WHO is citing these findings as a compelling reason to curb fossil fuel use and to take other steps to reduce air pollution levels. 

There is growing number of studies of the damage air pollution does to the human body.  Even low levels of many air pollutants can cause significant harm.  Particulate matter – especially so-called PM2.5 – is capable of penetrating deep into the lungs and entering the bloodstream, contributing to cardiovascular, cerebrovascular, and respiratory problems. 

Nitrogen dioxide is associated with respiratory diseases – especially asthma – and leads to respiratory symptoms, hospital admissions, and visits to emergency rooms.

The WHO is calling to governments around the world to take additional steps to improve air quality including adopting stricter air quality standards, supporting the transition to clean household energy sources, implementing stricter vehicle emission standards, reducing the use of incineration, and many other actions.

According to the WHO, cities in high-income countries fare better in terms of air quality, but very few places avoid unhealthy air entirely.   Seven million deaths a year are linked to unhealthy air quality.  It is a global crisis that cannot be ignored.

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Billions of people still breathe unhealthy air: new WHO data

Photo, posted December 1, 2021, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Conseguir un medicamento en las farmacias extranjeras no puede ser más difícil que la compra nocturna de alimentos. Si no se requiere una receta en línea para la compra de medicamentos, se puede comprar libremente, incluso no sólo en las farmacias, sino también en los supermercados, dijo un abogado y director general del grupo de consultoría vvCube Vadim Tkachenko.

Houseplants And Indoor Air Quality | Earth Wise

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Many of us have houseplants in our homes and offices.  The foliage and flowers add beauty and comfort to our indoor spaces.  But it turns out that there are health advantages as well.

Many studies have demonstrated that indoor houseplants can help keep you happier and healthier by improving your mood, reducing fatigue, lowering stress and anxiety, and improving focus.  Houseplants can also improve indoor air quality.

According to a new study by researchers from the University of Birmingham in the U.K. in partnership with the Royal Horticultural Society, ordinary houseplants can potentially make a significant contribution to reducing indoor air pollution.

The researchers tested three types of houseplants commonly found in homes in the U.K: Peace lily, corn plant, and fern arum.  These plants are easy to maintain and not overly expensive. 

In the study, the research team exposed these houseplants to nitrogen dioxide, which is a common indoor pollutant.  The plants were isolated in a test chamber containing levels of nitrogen dioxide comparable to what might be in an office situated next to a busy road.  The researchers found that all the plants were able to remove about half of the nitrogen dioxide in the chamber in just one hour.    

In a poorly ventilated small office with high levels of air pollution, the researchers calculated that five houseplants would remove up to 20% of the nitrogen dioxide.  In a larger space, the effect would be smaller – around 3.5% – although this figure could be increased by adding more plants.

Bringing nature indoors is one way to breathe cleaner air.

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Common houseplants can improve air quality indoors

Reducing air pollution with plants

Photo, posted September 21, 2014, courtesy of Olin Gilbert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deep Learning And Dirty Air | Earth Wise

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Poor air quality is a major global problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated seven million people every year.  In fact, 9 out of 10 people breathe air that contains more pollutants than what the WHO considers safe.  Air pollution is the fourth largest threat to human health, trailing only high blood pressure, dietary risks, and smoking.

But predicting pollution levels at a given place and time remains challenging.  According to a new study recently published in the journal Science of the Total Environment, scientists are turning to deep learning to improve air quality estimates. 

According to researchers, satellite observations and ground observations both measure air pollution, but both have major limitations.  For example, satellites may collect data at the same time and at the same location each day, but they miss how emissions may vary throughout the day.  Ground-based observations from weather stations do continuously collect data, but they only do so in a limited number of locations.    

As a result, scientists have turned to deep learning – a type of machine learning – to analyze the relationship between satellite and ground-based observations of nitrogen dioxide around Los Angeles.  Nitrogen dioxide is associated with emissions from traffic and power plants.  The researchers were able to rely on the learned relationship to take daily satellite observations and create hourly estimates of atmospheric nitrogen dioxide levels in approximately three mile grids.     

According to the research team, this study could be repeated for other greenhouse gases, and applied to different cities and regions – or even whole continents. 

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Scientists turn to deep learning to improve air quality forecasts

Air Pollution

Photo, posted November 4, 2019, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coronavirus Shutdowns And The Environment | Earth Wise

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Our stories often discuss how human activities change the natural environment.  With most of us confined to our homes, the lack of human activities is having profound effects on the environment.  We are talking about some of these this week.

The COVID-19 pandemic is a global catastrophe, but it has ironically been a boon for the environment.  By taking billions of people off the streets around the globe and slashing all forms of travel, the global environment has seen dramatic changes.

Sea turtles in many countries are prospering by not having to compete with humans for precious beach space.  Animals everywhere have more freedom to roam and are taking advantage of the opportunity. The Himalayas are visible from parts of India for the first time in decades.

Satellite imagery has shown dramatic drops in nitrogen dioxide emissions in China, where pollution from vehicles is a serious public health problem.  Similar reductions in air pollution are evident in India, Italy and even in Los Angeles.  The city that is notorious for its smog suddenly has pristine air.

In Venice, water in the canals has become clear in the absence of heavy boat traffic stirring up sediments from the bottom.  Wildlife that normally is invisible such as jellyfish are being spotted.

Not all the changes to animal behavior are desirable.  Some wildlife that have become dependent on humans as a source of food are becoming aggressive and are taking to the streets of cities to look for food.  Monkeys in Thailand are mobbing towns and brawling, hunting for things to eat.  Rats in New York City are fighting over suddenly meager food supplies.

In many ways, the natural world is reacting to much of humanity sheltering in place.

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On Earth Day 2020, coronavirus shutdowns are a gift to the environment

Photo, posted April 2, 2020, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Air Pollution | Earth Wise

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The environmental consequences of burning fossil fuels are a dominant topic.  The increasing changes in the climate have far-reaching effects across the globe and are a growing geopolitical crisis.  But the climate effects of fossil fuel emissions are by no means the only problem they cause.  

A new report by the Center for Research on Energy and Clear Air has, for the first time, attempted to quantify the global economic and health impacts of fossil fuel-caused air pollution.  In total, the estimate is that the economic and health costs of air pollution from burning fossil fuels totaled $2.9 trillion in 2018, calculated in the form of work absences, years of life lost, and premature deaths. The cost represents 3.3 percent of global GDP, or about $8 billion per day. 

The study focused on the health impacts of three specific types of pollutants:  nitrogen dioxide, ozone, and fine particulate matter, which has the greater impact.  Collectively, these pollutants cause about 1.8 billion days of missed work due to disease and $2.2 trillion in air pollution costs every year. Together, air pollution from these three pollutants is responsible for 4.5 million premature deaths around the world each year.

According to the report, the most premature deaths from fossil fuel-related air pollution in 2018 were in mainland China (1.8 million), India (1 million), and the United States (230,000). As a result, those three countries also faced the highest annual costs: $900 billion in China, $600 billion in the U.S., and $150 billion in India. 

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Toxic Air: The Price of Fossil Fuels (Full Report)

Photo, posted November 17, 2019, courtesy of Kristoffer Trolle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Converting A Toxin Into An Industrial Chemical | Earth Wise

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Nitrogen dioxide is a prominent air pollutant produced by internal combustion engines burning fossil fuels as well as by a variety of industrial processes.  It is a toxic material associated with a number of respiratory illnesses. 

Researchers at the University of Manchester in the UK along with an international team of scientists have developed a new advanced material that can convert nitrogen dioxide from an exhaust gas stream into useful industrial chemical using only water and air.

The material is a metal-organic framework (or MOF) that provides a selective, fully reversible, and repeatable capability to capture nitrogen dioxide.  MOFs are tiny three-dimensional structures that are porous and can trap gases inside as though there were tiny cages.  MOFs have enormous amounts of surface area for their size.  One gram of material can have a surface area as large as a football field.

The material, named MOF-520, can capture nitrogen dioxide at ambient temperatures and pressures and even at low concentration and during flow in the presence of moisture, sulfur dioxide, and carbon dioxide.  Such conditions are typical of the exhaust of internal combustion engines. In fact, the process works best at the typical temperature of automobile exhausts.

Once the nitrogen oxide is absorbed, treating the material with water in air converts it into nitric acid and restores the MOF for additional use.  Nitric acid is the basis of a multi-billion dollar industry with uses including agricultural fertilizers, rocket propellant, and nylon.  Thus, there is great potential for recouping the costs of using the MOF technology and even profiting from it.

It would be great to convert a toxic pollutant into valuable industrial chemicals.

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Clean air research converts toxic air pollutant into industrial chemical

Photo courtesy of the University of Manchester.

Earth Wise is a production of WAMC Northeast Public Radio.

Air Quality In The U.S.

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Globally, poor air is a serious problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated 7 million people every year.  In fact, 91% of the people on the planet live in places where air pollution exceeds WHO guideline limits. 

In the United States, air pollution has dramatically improved over the last four decades due in large part to federal regulations put in place under the Clean Air Act of 1970.  Fine particulate matter (known as PM2.5) and other pollution, including ozone, sulphur dioxide, and nitrogen dioxide, have all decreased during this time span. 

But according to recent research, this trend has unfortunately done an about-face.  New data reveals that air pollution has increased nationally since 2016.  An analysis of Environmental Protection Agency data by researchers at Carnegie Mellon University found that, on average, fine particulate pollution increased 5.5% across the country between 2016 and 2018. 

This increase in fine particulate pollution was associated with nearly 10,000 additional premature deaths in the United States during that time period. 

According to researchers, there are several factors likely causing this uptick in unhealthy air, including increases in both driving and the burning of natural gas.  Wildfires out west are also thought to be a major contributor. 

The researchers also suggest that a decrease in enforcement of the Clean Air Act may also be playing a role.  The law put in place strict air pollution standards for vehicles, factories, power plants, and other sources, and is credited with saving hundreds of thousands of lives.

It’s time for clean air to be recognized as a basic human right.

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America’s Air Quality Worsens, Ending Years of Gains, Study Says

Photo, posted April 6, 2007, courtesy of Brett Weinstein via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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