What Dirty Old Birds Can Teach Us About Air Pollution

Bird specimens at the Field Museum of Chicago

It couldn’t help but attract my attention; a neat row of old, preserved birds, their soft, feathery chests face-up: some were dark with soot, others by comparison, were clean. All came from an industrial area in the United States called the Rust Belt. That is key to the story.

The birds are part of a collection at The Field Museum in Chicago that dates back to the early 1900s. For a number of years, researchers and museum visitors had been noticing that some of the bird specimens looked clean while others appeared dirty. So recently, scientists from the museum and the University of Chicago decided to take a sharper look and see if they could come up with an answer.

What birds can tell us about black carbon pollution

The above red-headed woodpeckers and the yellow-throated larks (below) formed part of a study just released from the National Academy of Sciences that provided a surprising answer to the question. To decipher why some of the birds were more dirty than others, researchers studied over 1,300 museum specimens. What they discovered was that the birds’ degree of cleanliness corresponded directly with levels of air-borne pollution during their lifetimes, specifically black carbon.

Horned lark specimens

The birds’ chest feathers turned out to be a perfect tool for tracing the amount of black carbon that was present in the air over time. Why? Because the soot clung to their feathers and accumulated year after year.

“These birds were acting as air filters moving through the environment” said Shane DuBay, a graduate student at The Field Museum and the University of Chicago and one of the authors of the study. “The soot on these birds’ feathers allowed us to trace the amount of black carbon in the air over time, and we found that the air at the turn of the century was even more polluted than scientists previously thought,” he said.

Brown coal, which is used to power electricity, has a carbon content of 70-80 percent

Coal and black carbon

According to the Center for Climate and Energy Solutions, black carbon (BC), a long-known source of health and environmental concerns, has also recently emerged as a major contributor to global climate change, second only to C02. Until the mid-1950s, however, direct environmental samples were hard to come by.

Red-headed woodpecker

The birds, however, had lived in the part of the U.S. known as the manufacturing belt, a highly industrialized region historically reliant on coal. By analyzing the different specimens and plotting them on a time line, the researchers were able to go back in time and develop a correlation between the birds’ sootiness and a century’s worth of industrial and environmental approaches to combatting black carbon pollution. This gave them key insights into just how effective these policy approaches were.

For instance, during the depression, when there was a sharp drop in coal production, there was a drop in soot on the birds, too. Birds got dirtier again during World War II when wartime manufacturing drove up coal use. Birds got cleaner when people in the Rust belt started switching to gas to heat their homes in lieu of coal.

What is surprising to those of us who are worried about air pollution, is that the more recent specimens’ feathers are actually cleaner than those of the turn of the century (when we first started collecting birds, apparently).

Today’s horned larks are a lot cleaner

Still, the birds could be picking up less detectable amount of pollutants from other sources. All interesting things to ponder as the United States debates the future of coal, which currently provides 30 percent of the country’s energy. Meanwhile, the dirty birds provide silent testament to the legacies of our sooty history.


Trending In Health: Shinrin-Yoku (Forest Bathing)

Most of us are well aware that a walk in the woods is a breath of fresh air; especially if you’re stressed out from big city life or the artificial glow of computer screens. But now in a growing trend, people are heading to the woods to experience nature in a completely different way. It’s called forest bathing.

In Japan where the idea originated, forest bathing is known as Shinrin-yoku and it’s been shown to reduce stress, increase resistance to disease and promote well-being. No, people aren’t taking an actual bath in the woods, but they are engaging in something equally immersive. They are walking in the woods for the sole purpose of improving their health, following designated therapeutic ‘routes’, while tuning their minds into the colors, scents, sounds and feel of the forest.

Forest bathing has been a part of Japanese culture for years. And following a decade of official practice, it is now attracting attention worldwide. Currently, Shinrin-yoku (roughly translated as ‘taking in the atmosphere of the forest’) is gaining in popularity not only in Asia but in Europe, Scandinavia and America as well.

Why the trend? Because research shows there are measurable benefits to regular exposure to forest environments. In fact, just a few minutes spent walking in parks or green spaces can boost levels of energy and drive down everyday feelings of stress and anxiety.

Bamboo forest in Kyoto, Japan

Back in 1982, the Japanese were already aware of the harmful effects stress can have on the body. With job-related pressures on the rise, the Forest Agency of Japan began promoting forest bathing trips as part of a healthy lifestyle. Although forest recreation was a long-established form of relaxation, this was the first time the practice had been prescribed specifically to manage stress.

And, while no one could pinpoint exactly how it happened, more and more people were starting to report a positive therapeutic effect.

The science behind forest bathing

Researchers already knew that forest environments could have a profound effect on humans via their senses. As pleasant sensory experiences traveled to the brain, they interacted in positive ways with the part of the brain that controlled emotions and physiology. Scientists hypothesized that there might be a quantifiable link between forest bathing and a subsequent improvement in these functions.

The soothing sounds of a forest stream 

So in 2005, in an effort to better understand the longterm effects of forest bathing on people’s health, the Forest Agency instituted the Therapeutic Effects of Forests Plan. The goal was to discover what, if any, physiological benefits resulted from sending people into nature, specifically, forests, as a therapeutic practice. The scientific investigation, which wrapped up in 2014, uncovered some surprising information.

The study

To better understand the effects of an individual’s exposure to a forest or its components (such as streams, blossoms or wood), the researchers conducted experiments using 456 subjects and 38 forests over a period of four years. Subjects were randomly divided into two groups and were given identical single rooms as lodgings and identical meals and water to control for background environmental conditions.

On the first day of each experiment, half of the subjects took a walk in a forest or wooded area for a few hours, while the other half spent an equal time walking in the city. On the second day, the groups switched places. Scientists measured their subjects’ salivary cortisol, blood pressure, pulse rate and heart rate variability before breakfast and both before and after walking to see if there were any measurable effects.

Phytoncides emitted by trees can improve human health, too

The studies revealed some interesting dynamics. Compared to the city walkers, those individuals who spent time in the woods had significantly lower concentrations of cortisol, as well as lower pulse and blood pressure rates. Their sympathetic nerve activity (which activates the fight or light responses) was also reduced. Most significantly, exposure to phytoncides (aromatic chemicals or oils emitted by plants and trees to protect themselves from insects and disease) had a lasting impact on peoples’ immune systems, boosting their natural killer cells and anticancer proteins by an astonishing 40 percent.

As a result of this study, forest bathing has now become an integral part of preventative medicine in Japan; so widespread that a quarter of the population is reported to be practicing it on over 55 official Forest Therapy Trails. Some Japanese companies are even starting to include forest therapy in their healthcare benefits, offering wellness check-ups in the woods as a part of a new ‘nature prescription.’

Forest and humans : We’re in this together

Humans have been getting ‘in touch’ with nature for ages and almost no one would dispute the natural world’s beneficiary effect. While this is the first scientific evidence of forests’ positive impact on humans, some people point to the human evolutionary process itself as proof that nature and humans have always had a deep-seated connection. They note that until recently, most of the 5 million years of our existence has been lived in the natural environment.

Consider this: If human physiological functions were designed for living in nature, then life in modern, artificial environments must by definition be innately stressful. Immersing the body in nature puts it back where it was meant to be.

Nuuksio National Park, Finland

The Master Samurai Spain, who has led studies on Shinrin-yoku in Andalusian forests for the past 10 years, agrees. He believes the root of the problem is that human beings are not adapted to live in hostile environments such as cities. As a result, those suffering from modern-day stresses and anxiety have weakened immune systems that cause them to become sick. Forest bathing allows the body to absorb beneficial compounds associated with millions of years of plant growth. This helps it fortify its defenses.

Trees aren’t just about good looks

Trees aren’t just beautiful, they provide shade that cools our homes and bodies. Like all plants, they perform photosynthesis, converting sunlight into food for insects, wildlife and people. They also act as nature’s water filters, drawing on the dense communities of microbes surrounding their roots to clean water in exchange for nutrients. And their leaves filter air pollution on a grand scale, too.

Trees provide wood for our fires and building materials for our furniture and homes. They stabilize our planet’s soil. And their soothing sounds, pungent smells and visual stimuli have calmed our anxious minds for centuries. Now comes the first scientific proof of what we’ve innately known all along. Forest bathing may be the cure for what ails us.

Intrigued by the idea? Spafinder.com is a great resource for places offering the practice.


How To Create Winter Interest In the Garden

cover 2

“I prefer winter and fall, when you feel the bone structure in the landscape – the loneliness of it – the dead feeling of winter. Something waits beneath it – the whole story doesn’t show.”

~  Andrew Wyeth

I grew up near Chadd’s Ford, Pennsylvania in the heart of the Brandywine Valley. The American painter, Andrew Wyeth, drew his inspiration from this place, beautifully capturing the unique winter landscape in a subdued mix of browns, whites, tans and grays. My winters were painted in the same monochromatic palette, made all the more rich by the stark outlines of bare shrubbery and gnarled tree trunks silhouetted against the white winter sky. Continue reading

Christmas Tree Farm Memories

chr tree cover 1

According to the latest statistics, 2015 has so far been a big year for the purchase of live Christmas trees. This is interesting data given the fact that more and more people are turning to artificial trees for their holiday decorating. Yes, I’ve been tempted, but I still prefer the smell and touch of a live tree. To me, there is nothing like the deep earthy aroma of a fresh Douglas fir to liven up my holiday days. Continue reading

Ten Steps To A Happy Life


Spring is a good time to start fresh and focus on what’s really important in life. For me, the month of April is a time of introspection. I make a mental list of what parts of my life need to be reorganized, adjusted or just plain thrown out.  Then I replenish my house with a happy mind.

Just like spring cleaning, the job is not effortless. But it always feels good once the task is done. Here are ten tips to get you started.

Continue reading

Take Time, Slow Down and Smell the Leaves

There’s no better time than autumn to get outside and smell the leaves. The cooler temperatures and colorful show offer a great opportunity to reconnect with the natural world. With its unmistakable earthy aroma, fall offers us a chance to renew our spirits and to recharge.

I take pleasure in all the leafy details of the season: the delicate remains of the tooth-edged brown oak, the fiery red maple formed like a palm and the heart-shaped yellow linden. Held aloft on the fragrant air, these simple shapes flutter down from bare branches to form crazy quilts on the still-warm soil. As I walk, a crisp, crackling sound rises from beneath my feet.  I savor the heady aromas; fragrant cinnamon, orange spice and the powerful scent of dry leaves roasting in the autumn sun.

What is it about decaying leaves that summons up our deepest memories? How can one whiff of a rotting oak stir our reflection, catapulting us back into the giant leaf piles of our youth?

My view is that the answer lies not only in fall’s foliage, but also in something less tangible – its smell. More inscrutable than seeing or hearing, the experience of smelling opens pathways to a deep-seated awareness that lies dormant in us all. Untouched by human language, this awareness, once awakened, recalls the child we once were and who still exists inside us.

Floating upward through the annals of time, the distinctive smell of autumn leaves reconnects us to this child, reminding us of our own particular story, our unique pathway through life and our timeless link to the natural world.