News / Science & Technology

Tree Bark Shows Global Spread of Toxic Chemicals

Tree Bark Shows Global Spread of Toxic Chemicalsi
X
March 15, 2013 9:14 PM
The chemicals used to retard fire in consumer products such as furniture and clothing can become toxic pollutants when they wind up in the environment. And they are in the environment - all over the world - in the water, the soil, the plants, and the air. Tracking the spread of these chemicals has been a major challenge, but it just got easier. Erika Celeste reports for VOA on the new technique.
Tree Bark Shows Global Spread of Toxic Chemicals
Erika Celeste
The US Environmental Protection Agency has begun a major new risk assessment of 20 flame-retardant chemicals. These compounds have been widely used for decades in many consumer products, from furniture to sleepwear. But the chemicals are toxic.  And although they are being phased out, they have become a worldwide pollutant and a serious threat to human health.  Measuring their presence in our water, soil, and air has been a major challenge.  But, a new technique promises to make it much easier.

And they are in the environment all over the world; in the water, soil, plants and the air. Tracking the spread of these chemicals has been a major challenge, but it just got easier.

It takes less than 90 seconds for a spark to grow to an inferno. Flame retardants can prevent this.

But Indiana University researcher Amina Salamova points out that when the chemicals evaporate, they become toxic air pollutants.

On the campus of Indiana University, Amina Salamova studies polybrominated diphenyl ethers [PBDEs], and other chemical environmental pollutants. PBDEs are widely used as flame retardants but have been associated with adverse effects on human health.

“They can have an effect on neurological development, on reproductive system, and they can effect your thyroid endocrine system,” said Salamova.

Concerns about those effects have prompted regulatory agencies and some manufacturers to phase out the use of many flame retardant chemicals. But PBDEs can persist for years in the environment, and scientists do not know precisely where or how they spread.

Novel tool

That’s why Salamova and her co-researcher Ronald Hites developed a new technique to measure the presence and concentration of flame retardant chemicals in the air, by sampling the bark of trees.  

“The tree’s ideal because it’s sitting there passively soaking up these compounds out of the atmosphere,” said Hites.

A tree’s bark provides a large surface area that takes in chemicals as both vapor and particles. Also, because a layer of bark remains on the tree for five years or so before being shed, it provides a unique record of the environment over time.

Salamova said the tree-bark approach has many advantages over the current, more complex sampling method, which involves pumping air through expensive equipment, and requires plenty of manpower, and electricity.

“So what I see in future for tree bark is the ability to use this method in developing countries which don’t have a lot of funding for elaborate atmospheric studies. Also we can use this method in remote sites where there is no power,” said Salamova.

Global initiative

With the help of the Global Atmospheric Passive Sampling network, an international monitoring initiative, Salamova and Hites received bark samples from 12 locations around the world, including Norway, the Czech Republic, South Africa, Nepal, Indonesia, the United States and Canada.  

“So this way, you collect about 50 gram of bark, you can collect it from either side of the tree,” said Salamova.

Researchers use a chisel and hammer to tap out a few pieces of bark, wrap them in foil and ship them back to Indiana University for chemical analysis.

Pervasive evidence

Studying those samples in the lab, the researchers found evidence of flame retardants in the atmosphere at all 12 locations. Hites was not surprised to find the highest concentrations at urban sites in Ontario, Canada and around the U.S. Great Lakes.

What was unexpected was the high level of chemicals in some very remote rural regions of Indonesia and Tasmania.

“There’s hardly anybody there. It’s really out of the winds of possible industrial sources. But still these compounds are present there at reasonably high levels, they’re slightly below average, but again measurable levels in the tree bark from Tasmania,” said Hites.

The researchers’ findings, detailed in the journal Environmental Science and Technology, show that these compounds are migrating surprisingly long distances. Salamova says they hope to continue collecting samples to build a global database so scientists and regulatory agencies can understand the pervasiveness of chemical retardants and find ways to remove them from the environment.

You May Like

Video Positive Messaging Helps Revamp Ethiopia's Image

In country once connected with war, poverty, famine, headlines now focus on fast-growing economy, diplomatic reputation More

Russian Activist Thinks Kremlin Ordered Nemtsov's Death

Alexei Navalny says comments of Russian liberals who think government wasn't involved are 'nonsense.' More

Video Land Disputes Rise Amid Uganda Oil Boom

Investors appear to be cashing in by selling parcels of land to multiple buyers More

This forum has been closed.
Comment Sorting
Comments
     
by: Rie K.Maegawa from: Japan
March 31, 2013 1:50 AM
We should rate this experiment highly from the following points. First, this laboratory and field work does not kill any living creatures. Secondly, the samples are really widely collected. As the result, the researchers have found the unexpected high leverl of the chemicals in the very remote rural regions of Indonesia and Tasmania. Building a global database for the data is significant.

by: Chinara from: Azerbaijan
March 19, 2013 8:59 PM
Is it possible to conduct tests on dioxin by this method? As dioxin also is very toxic and persistent pollutant and accumulates in the tissue from all type of environment.

by: cleanair from: Tasmania
March 17, 2013 8:38 AM
Thank you to the researchers who have discovered this process.
I live in Tasmania. There are about half a million people live here.
These results are interesting because our CSIRO tells us we have the cleanest air in the world.
In Response

by: Ian from: USA
March 18, 2013 11:28 AM
You may actually still have the cleanest air in the world.
It is just the whole world's air getting worse

by: Kitagawa Keikoh from: Jiyugaoka, JPN
March 15, 2013 8:00 PM
We are threatening from China's PM2.5 in Japan. They are the worst pollution producer in the world. They don't have enough technology to prevent pollutions and they are wasting energy. That is a new weapon of harasment for neighbor countries.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Positive Messaging Transforms Ethiopia's Imagei
X
Marthe van der Wolf
March 03, 2015 9:03 PM
Ethiopia was once known for famine and droughts. Now, headlines more often point to its fast-growing economy and its emergence as a regional peacemaker. How has Addis Ababa changed the narrative? VOA's Marthe van der Wolf reports.
Video

Video Positive Messaging Transforms Ethiopia's Image

Ethiopia was once known for famine and droughts. Now, headlines more often point to its fast-growing economy and its emergence as a regional peacemaker. How has Addis Ababa changed the narrative? VOA's Marthe van der Wolf reports.
Video

Video Cyber War Rages Between Iran, US

A newly published report indicates Iran and the United States have increased their cyber attacks on each other, even as their top diplomats are working toward an agreement to guarantee Iran does not develop a nuclear weapon and to free Iran from international sanctions. The development is part of a growing global trend. VOA’s Al Pessin reports from London.
Video

Video Answers Elude Families of MH370 Passengers

For the families on board Malaysia Airlines flight MH370, an airline official’s statement nearly one year ago that the plane had lost contact with air traffic control at 2:40 AM is the only thing that remains confirmed. William Ide reports.
Video

Video Land Disputes Arise Amid Uganda Oil Boom

Ugandan police say there has been a sharp increase in land disputes, with 10 new cases being reported each day. The claims come amid an oil boom as investors appear to be cashing in by selling parcels of land to multiple buyers. Meanwhile, the people who have been living on the land for decades are chased away, sometimes with a heavy hand. VOA's Serginho Roosblad reports.
Video

Video In Russia, Many Doubt Opposition Leader's Killer Will Be Found

The funeral has been held in Moscow for Boris Nemtsov, the opposition leader who was assassinated late Friday just meters from the Kremlin. Nemtsov joins a growing list of outspoken critics of Russia under the leadership of President Vladimir Putin who are believed to have been murdered for their work. VOA’s Daniel Schearf reports from Moscow.
Video

Video Simulated Astronauts Get Taste of Mars, in Hawaii

For generations, people have dreamed of traveling to Mars to explore Earth's closest planetary neighbor. VOA's Mike O'Sullivan reports that while space agencies like NASA are planning manned missions to the planet, some volunteers in Hawaii are learning how humans will cope with months in isolation on a Mars base.
Video

Video Destruction of Iraq Artifacts Shocks Archaeologists

The city of Mosul was once one of the most culturally rich and religiously diverse cities in Iraq. That tradition is under attack by members of the Islamic State who have made Mosul their capital city. The Mosul Museum is the latest target of the group’s campaign of terror and destruction, and is of grave concern to archaeologists around the world. VOA’s Kane Farabaugh reports.
Video

Video Smartphones May Help in Diagnosing HIV

Diagnosing infections such as HIV requires expensive clinical tests, making the procedure too costly for many poor patients or those living in remote areas. But a new technology called lab-on-a-chip may make the tests more accessible to many. VOA’s George Putic reports.
Video

Video Afghan Refugees Complain of Harassment in Pakistan

Afghan officials have expressed concern over reports of a crackdown on Afghan refugees in Pakistan following the Peshawar school attack in December. Reports of mass arrests and police harassment coupled with fear of an uncertain future are making life difficult for a population that fled its homeland to escape war. VOA’s Ayesha Tanzeem reports from Islamabad.
Video

Video Ukrainian Volunteers Prepare to Defend Mariupol

Despite the ongoing ceasefire in Ukraine, soldiers in the city of Mariupol fear that pro-Russian separatists may be getting ready to attack. The separatists must take or encircle the city if they wish to gain land access to Crimea, which was annexed by Russia early last year. But Ukrainian forces, many of them volunteers, say they are determined to defend it. Patrick Wells reports from Mariupol.
Video

Video Moscow Restaurants Suffer in Bad Economy, Look for Opportunity

As low oil prices and Western sanctions force Russia's economy into recession, thousands of Moscow restaurants are expected to close their doors. Restaurant owners face rents tied to foreign currency, while rising food prices mean Russians are spending less when they dine out. One entrepreneur in Moscow has started a dinner kit delivery service for those who want to cook at home to save money but not skimp on quality. VOA's Daniel Schearf reports.
Video

Video Presidential Hopefuls Battle for Conservative Hearts and Minds

One after another, presumptive Republican presidential contenders auditioned for conservative support this week at the Conservative Political Action Conference held outside Washington. The rhetoric was tough as a large field of potential candidates tried to woo conservative support with red-meat attacks on President Barack Obama and Democrats in Congress. VOA Political Columnist Jim Malone takes a look.
Video

Video Southern US Cities Preserve Civil Rights Heritage to Boost Tourism

There has been a surge of interest in the American civil rights movement of the 1950s and '60s, thanks in part to the Hollywood motion picture "Selma." Five decades later, communities in the South are embracing the dark chapters of their past with hopes of luring tourism dollars. VOA's Chris Simkins reports.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More