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

Multimedia Obama Defends Immigration Action

Obama says with his executive action on immigration, enforcement resources will be focused on 'felons, not families; criminals, not children' More

US-Led Airstrikes in Syria Kill Over 900: Monitoring Group

British-based Syrian Observatory for Human Rights says the toll includes more than 50 civilians, five of them women and eight of them children More

Report: Obama Broadens US Combat Role in Afghanistan

The New York Times says resident Barack Obama has signed a classified order extending the role of US troops in Afghanistan for another year 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.
New Skateboard Defies Gravityi
X
November 21, 2014 5:07 AM
A futuristic dream only a couple of decades ago, the hoverboard – a skateboard that floats above the ground - has finally been made possible. While still not ready for mass production, it promises to become a cool mode of transport... at least over some surfaces. VOA’s George Putic reports.
Video

Video New Skateboard Defies Gravity

A futuristic dream only a couple of decades ago, the hoverboard – a skateboard that floats above the ground - has finally been made possible. While still not ready for mass production, it promises to become a cool mode of transport... at least over some surfaces. VOA’s George Putic reports.
Video

Video Falling Gas Prices Impact US Oil Extraction

With the price of oil now less than $80 a barrel, motorists throughout the United States are benefiting from gas prices below $3 a gallon. But as VOA’s Kane Farabaugh reports, the decreasing price of petroleum has a downside for the hydraulic fracturing industry in the United States.
Video

Video Tensions Build on Korean Peninsula Amid Military Drills

It has been another tense week on the Korean peninsula as Pyongyang threatened to again test nuclear weapons while the U.S. and South Korean forces held joint military exercises in a show of force. VOA’s Brian Padden reports from the Kunsan Air Base in South Korea.
Video

Video Mama Sarah Obama Honored at UN Women’s Entrepreneurship Day

President Barack Obama's step-grandmother is in the United States to raise money to build a $12 million school and hospital center in Kogelo, Kenya, the birthplace of the president's father, Barack Obama, Sr. She was honored for her decades of work to aid poor Kenyans at a Women's Entrepreneurship Day at the United Nations.
Video

Video Gay Evangelicals Argue That Bible Does Not Condemn Homosexuality

More than 30 U.S. states now recognize same-sex marriages, and an increasing number of mainline American churches are blessing them. But evangelical church members- which account for around 30 percent of the U.S. adult population - believe the Bible unequivocally condemns homosexuality. VOA's Jerome Socolovsky reports that gay, lesbian, bisexual and transgender evangelicals are coming out. Backed by a prominent evangelical scholar, they argue that the traditional reading of the bible is wrong.
Video

Video Ebola Economic Toll Stirs W. Africa Food Security Concerns

The World Bank said Wednesday that it expects the economic impact of the Ebola outbreak on the sub-Saharan economy to cost somewhere betweenf $3 billion to $4 billion - well below a previously-outlined worst-case scenario of $32 billion. Some economists, however, paint a gloomier picture - warning that the disruption to regional markets and trading is considerable. Henry Ridgwell reports from London.
Video

Video Mexico Protests Escalate Over Disappearances

Protests in Mexico over 43 students missing since September continue to escalate, reflecting growing anger among Mexicans about a political system they view as corrupt, and increasingly tainted by the drug trade. Mounting outrage over the disappearances is now focused on the government of President Enrique Pena Nieto, accused of not doing enough to end insecurity in the country. More from VOA's Victoria Macchi.
Video

Video US Senate Votes Down Controversial Oil Pipeline - For Now

The U.S. Senate has rejected construction of a controversial pipeline to transport Canadian oil to American refineries. The $5 billion project still could be approved next year, but it faces a possible veto by President Barack Obama. As VOA’s Michael Bowman reports, the pipeline has exposed deep divisions in Congress about America’s energy future.
Video

Video Can Minsk Cease-fire Agreement Hold?

Growing tensions between government troops and separatists in eastern Ukraine further threaten a cease-fire agreement reached two months ago in the Belarusian capital of Minsk. Critics of U.S. policy in Ukraine say it is time the Obama administration gives up on that much-violated cease-fire and moves toward a new deal with Russia. VOA's Scott Stearns has more.
Video

Video Chaos, Abuse Defy Solution in Libya

The political and security crisis in Libya is deepening, with competing governments and, according to Amnesty International, widespread human rights violations committed with impunity. VOA’s Al Pessin reports from London.
Video

Video US Hosts Record 866,000 Foreign Students

Close to 900,000 international students are studying at American universities and colleges, more than ever before. About half of them come from Asia, mostly China. The United States hosts more foreign students than any other country in the world, and its foreign student population is steadily growing. Zlatica Hoke reports.
Video

Video Ferguson Church Grapples with Race Relations

Many white residents of Ferguson, Missouri, say they chose to live there because of the American Midwest community's diversity. So, they were shocked when a white police officer killed an unarmed black teenager in August – and shaken by the resulting protests and violence. Some local churches are leading conversations on how to go forward. VOA’s Ayesha Tanzeem reports.

All About America

AppleAndroid