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 Snowstorm Sweeps Northeastern US

'This is nothing like we feared it would be,' New York City Mayor Bill de Blasio says; he had warned storm could be one of worst in city history More

Millions of Displaced Nigerians Struggle With Daily Existence

Government acknowledges over a million people displaced in 2014 due to fight against Boko Haram insurgency More

Facebook: Internal Error to Blame for Outages

Temporary outage appeared to spill over and temporarily slow or block traffic to other major Internet sites 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.
Obama Urges Closer Economic Ties During Historic India Visiti
X
Aru Pande
January 26, 2015 9:33 PM
U.S. President Barack Obama says the United States and India must do better to capitalize on untapped potential in their economic relationship - by removing some of the roadblocks to greater trade and investment. As VOA correspondent Aru Pande reports from New Delhi, Obama spoke after participating in India’s Republic Day celebration.
Video

Video Obama Urges Closer Economic Ties During Historic India Visit

U.S. President Barack Obama says the United States and India must do better to capitalize on untapped potential in their economic relationship - by removing some of the roadblocks to greater trade and investment. As VOA correspondent Aru Pande reports from New Delhi, Obama spoke after participating in India’s Republic Day celebration.
Video

Video US, EU Threaten New Russia Sanctions Over Ukraine

U.S. President Barack Obama has blamed Russia for an attack by Ukrainian separatists that left dozens dead in the port of Mariupol and cast further doubt on the viability of last year’s cease-fire with the Kyiv government. VOA’s Michael Bowman reports from Washington.
Video

Video White House Grapples With Yemen Counterterrorism Strategy

Reports say the U.S. has carried out a drone strike on suspected militants in Yemen, the first after President Barack Obama offered reassurances the U.S. is continuing its counterterrorism operations in the country. The future of those operations has been in question following the collapse last week of Yemen’s government. VOA White House correspondent Luis Ramirez reports.
Video

Video Kerry Warns Against Violence in Nigeria Election

US Secretary of State John Kerry visited Nigeria Sunday in a show of the level of concern within the U.S. and the international community over next month’s presidential election. Chris Stein reports.
Video

Video Zoo Animals Show Their Artistic Sides

The pursuit of happiness is so important, America's founding fathers put it in the Declaration of Independence. Any zookeeper will tell you animals need enrichment, just like humans do. So painting, and even music, are part of the Smithsonian National Zoo's program to keep the animals happy. VOA’s June Soh met some animal artists at the zoo in Washington. Faith Lapidus narrates.
Video

Video Worldwide Photo Workshops Empower Youth

Last September, 20 young adults from South Sudan took part in a National Geographic Photo Camp. They are among hundreds of students from around the world who have learned how to use a camera to tell the stories of the people in their communities through the powerful medium of photography. Three camp participants talked about their experiences recently on a visit to Washington. VOA’s Julie Taboh reports.
Video

Video Saudi, Yemen Developments Are Sudden Complications for Obama

The death of Saudi Arabia's King Abdullah and the collapse of Yemen’s government have cast further uncertainty on U.S. efforts to fight militants in the Middle East and also contain Iran’s influence in the region. VOA White House correspondent Luis Ramirez reports on the new complications facing the Obama administration and its Middle East policy.
Video

Video Progress, Some Areas of Disagreement in Cuba Talks

U.S. and Cuban officials are reporting progress from initial talks in Havana on re-establishing diplomatic ties. U.S. Assistant Secretary of State (for Western Hemisphere Affairs) Roberta Jacobson said while there was agreement on a broad range of issues, there also are some “profound disagreements” between Washington and Havana. VOA State Department correspondent Pam Dockins has the story.
Video

Video US, Japan Offer Lessons as Eurozone Launches Huge Stimulus

The Euro currency has fallen sharply after the European Central Bank announced a bigger-than-expected $67 billion-a-month quantitative easing program Thursday - commonly seen as a form of printing new money. Henry Ridgwell reports for VOA from London on whether the move might rescue the eurozone economy -- and what lessons have been learned from similar programs around the world.
Video

Video Nigerian Elections Pose Concern of Potential Conflict in 'Middle Belt'

Nigeria’s north-central state of Kaduna has long been the site of fighting between Muslims and Christians as well as between people of different ethnic groups. As the February elections approach, community and religious leaders are making plans they hope will keep the streets calm after results are announced. Chris Stein reports from the state capital, Kaduna.
Video

Video As Viewership Drops, Obama Puts His Message on YouTube

Ratings reports show President Obama’s State of the Union address this week drew the lowest number of viewers for this annual speech in 15 years. White House officials anticipated this, and the president has decided to take a non-traditional approach to getting his message out. VOA White House correspondent Luis Ramirez reports.
Video

Video S. Korean Businesses Want to End Trade Restrictions With North

Business leaders in South Korea are calling for President Park Geun-hye to ease trade restrictions with North Korea that were put in place in 2010 after the sinking of a South Korean warship.Pro-business groups argue that expanding trade and investment is not only good for business, it is also good for long-term regional peace and security. VOA’s Brian Padden reports.

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

All About America

AppleAndroid