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The Silent Killer | Earth Wise

April 26, 2021 By EarthWise Leave a Comment

Air pollution is deadly. Studies have found that particles from air pollution can enter our lungs and bloodstream, contributing to major health conditions including heart disease, stroke, cancer, and kidney disease. Globally, air pollution is responsible for the premature deaths of millions of people every year.

The first line of defense against air pollution is ambient air quality standards. But according to researchers from McGill University, more than half of the world’s population lives without the protection of adequate air quality standards.

The research team focused on a specific type of air pollution called particulate matter 2.5 (more commonly called PM2.5). PM2.5 refers to tiny particles or droplets in the air that are two and one half microns or less in width. These tiny particles are responsible for an estimated 4.2 million premature deaths every year globally, including more than one million deaths in China, nearly 200,000 in Europe, and more than 50,000 in the United States.

In the study, which was recently published in the Bulletin of the World Health Organization, the researchers found that where there are air quality protections, the standards are often worse than what the WHO considers safe. Some regions with high air pollution levels, like the Middle East, don’t even measure PM2.5 air pollution. The researchers found that the weakest air quality standards are often violated, while the strictest standards are often met.

More than half of the world’s population is in urgent need of adequate air quality standards.

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Air pollution: The silent killer called PM 2.5

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

Earth Wise is a production of WAMC Northeast Public Radio.

Much More Microplastics In The Ocean | Earth Wise

January 28, 2020 By EarthWise Leave a Comment

We’ve been hearing more and more about plastic contamination (microplastics) in the ocean. It is pulled from the nostrils of sea turtles, found in Antarctic waters, and tracked in increasing quantities in sedimentary layers dating back to the 1940s. A new study by researchers from the Scripps Institution of Oceanography suggests that there could be a million times more pieces of plastic in the ocean than previously estimated.

Oceanographers found that some of the tiniest countable microplastic particles in seawater occur at much higher concentrations than previously measured. Apparently, the traditional way of counting marine microplastics most likely misses the smallest particles, and therefore underestimates the number of particles by a factor of anywhere from 10,000 to a million.

The new measurements estimate that the oceans may be contaminated by 8 million pieces of so-called mini-microplastics per cubic meter of water. Earlier studies that only looked at larger pieces of plastic found only 10 pieces per cubic meter.

Microplastic studies typically trawl or pull a fine net behind a ship to collect samples. But the meshes previously used could only capture plastics as small as 333 microns. The new study found plastic particles as small as 10 microns, which is less than the width of a human hair.

Plastics keep breaking down into smaller and smaller particles, but they are so chemically strong that their chemical bonds don’t break down. They remain bits of plastic. Scientists are concerned that these particles can get small enough to enter the human bloodstream. The potential effects on human health are not well known and not extensively studied.

The problem of plastics just keeps getting bigger.

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Microplastics a million times more abundant in the ocean than previously thought

Photo courtesy of UC San Diego.

Earth Wise is a production of WAMC Northeast Public Radio.

Geoengineering And Volcanoes

November 14, 2019 By EarthWise Leave a Comment

Solar geoengineering is a theoretical strategy for curbing the effects of climate change by introducing aerosol particles in the upper atmosphere to reflect some of the Sun’s radiation back into space and thereby cool the planet. It would basically be intentionally tinkering with the climate system on a global scale.

The concept is fraught with the danger of unintended consequences and most experts consider the idea almost unthinkable. But there are those who see it as a last resort if all our other efforts to mitigate the effects of climate change are unsuccessful.

Proponents of the idea like to describe the technique as being like a human-made volcano. Major volcanic eruptions spew ash particles into the atmosphere which can linger for as long as a few years. The result is cooler temperatures, sometimes across much of the globe. The Krakatoa eruption of 1883 lowered average Northern Hemisphere temperatures by more than 2 degrees and created chaotic weather patterns until about 1888.

Researchers at the Carnegie Institution and two Chinese research institutions used sophisticated modeling techniques to compare the effects on the climate of a volcanic eruption with long-term geoengineering deployment.

They found that the volcanic eruption created a greater temperature difference between the land and sea than the geoengineering and resulted in very different precipitation scenarios. In both cases, there would be less available water for people on land.

Overall, the study demonstrated that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be very cautious about extrapolating too much from them. It is important to evaluate geoengineering from an informed position, but the truth is that it represents a great and perilous unknown.

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Geoengineering Versus A Volcano

Photo, posted November 1, 2002, courtesy of the NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Microplastic Diet

July 29, 2019 By EarthWise Leave a Comment

According to a new study published in the journal Environmental Science & Technology, Americans consume more than 70,000 microplastic particles every year from the food they eat, the water they drink, and the air they breathe.

While the health impacts of ingesting these tiny particles are largely unknown, there is the potential for the plastic to enter human tissues and cause an immune response or perhaps release toxic chemicals into the body.

The analysis by biologists at the University of Victoria in Canada examined data from 26 previous studies on microplastic contamination. It found that Americans eat and drink an estimated 39,000 to 52,000 microplastic particles each year, depending on their age and sex. The numbers jump to 74,000 to 121,000 when inhalation of microplastics is included.

Americans who drink water solely from plastic bottles consume an additional 90,000 particles annually, compared to only 4,000 particles for people who only drink tap water.

The researchers warn that their findings are likely to be drastic underestimates of the problem. Several major U.S. food groups – including poultry, beef, dairy, grains, and vegetables – have not been studied for their microplastic contamination. Thus, the estimate of microparticle ingestion is associated with only 15% of an average person’s caloric intake. Furthermore, there is no assessment currently available for how much plastic might be entering our bodies from food packaging.

The report’s findings suggest that microplastics will continue to be found in the majority if not all items intended for human consumption. Realistically, the only way to reduce the human consumption of microplastics will be to reduce the production and use of plastics.

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Americans Consume Tens of Thousands of Microplastic Particles Every Year

Photo, posted June 18, 2016, courtesy of Sirirat Kornsongkaew via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fire-Driven Thunderstorms

March 6, 2019 By EarthWise Leave a Comment

In 2016 and 2017, wildfires in western Canada spawned thunderstorms that ignited additional fires, in some cases tens of miles away from the original fire. These fire-triggered thunderstorms are technically known as pyrocumulonimbus clouds, or “pyroCb’s”.

The physics of pyroCb’s is complex. When super-heated updrafts from an intense fire suck smoke, ash, burning materials, and water vapor high into the air, these elements cool and form so-called fire clouds that look and act like the cumulonimbus clouds associated with classic thunderstorms. What is different is that the heat and particulates in the smoke almost always arrest the ability of the cloud to produce rain. Instead, what remains is a lightning storm that moves across the landscape, triggering more fires.

These PyroCb events appear to be happening far more often, producing more energy, and erupting in places where they have never been seen before. As the world warms, wildfires themselves are becoming larger and hotter. In the past decade, wildfires have been burning more than twice as many acres as they did before the turn of the 21^st century. Along with the growth in wildfire activity, there has been an increase in PyroCb events, and there are now an average of 25 per year in western North America.

Apart from starting new fires, pyroCb’s also have similar effects as moderate-sized volcanic eruptions. Smoke and aerosols from wildfires can rise high into the stratosphere, where they can linger for months. Eventually, the particles carried aloft in the atmosphere do come down, dumping dangerous chemicals on far flung regions of the earth. But unlike volcanic eruptions, which are relatively rare events, pyroCb’s are happening more and more each year.

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