Tag Archives: soot

Smoke Plume.

Air pollution soots its way into mothers’ placentas — maybe the fetus, as well

Tiny particles of carbon associated with air pollution can find their way into the placenta of pregnant women, a new paper reports. The findings cast light on the danger air pollution poses on developing fetuses.

Smoke Plume.

Image via Pixabay.

Even unborn babies suffer from the poor quality of our air, new research shows. Previous research has linked complications such as premature birth, low birth weight, infant mortality, and childhood respiratory problems to a pregnant woman’s exposure to air pollution. The present paper adds to that body of evidence, explaining that when pregnant women breathe polluted air, particles of soot are able to travel through the bloodstream to the placenta.

The smell of soot in the morning

The findings were presented by Dr. Norrice Liu, a pediatrician and clinical research fellow, and Dr. Lisa Miyashita, a post-doctoral researcher Sunday at the European Respiratory Society International Congress in Paris.

“We’ve known for a while that air pollution affects foetal development and can continue to affect babies after birth and throughout their lives,” Dr. Miyashita explained.

“We were interested to see if these effects could be due to pollution particles moving from the mother’s lungs to the placenta. Until now, there has been very little evidence that inhaled particles get into the blood from the lung.”

The team worked with five pregnant women, all of whom were living in London. The five were all non-smokers, pregnant with uncomplicated pregnancies, and were due to have planned cesarean section deliveries at the Royal London Hospital.

After they gave birth, the team retrieved their placentas for study. The researchers were particularly interested in cells known as placental macrophages. Some of their previous research involved identifying and measuring soot particles in the human airway by investigating these cells.

Macrophages of all walks of life permeate the body. They’re an integral part of the immune system and work by gobbling up foreign, harmful particles such as bacteria or soot, and then attacking them chemically — i.e. ‘digesting’ them. In the placenta, they’re tasked with keeping the fetus secure.

The team looked at roughly 3,500 placental macrophage cells retrieved from the five participants. Using a high-powered microscope, they investigated the cells for signs of soot. Some 60 cells contained these particles, the paper reports, totaling roughly 72 black areas. On average, each placenta contained around five square micrometers of this black substance.

Subsequent experiments with an electron microscope showed this black substance was made up of tiny carbon particles — soot.

“We thought that looking at macrophages in other organs might provide direct evidence that inhaled particles move out of the lungs to other parts of the body,” Dr Liu explains. “We were not sure if we were going to find any particles and if we did find them, we were only expecting to find a small number of placental macrophages that contain these sooty particles.”

“This is because most of them should be engulfed by macrophages within the airways, particularly the bigger particles, and only a minority of small sized particles would move into the circulation.

The results form the first solid evidence of soot particles passing from the lungs into the circulatory system and, from there, to the placenta. As of now, the team cannot say for sure whether the particles can also make their way into the fetus, but note that “this is indeed possible” given the current findings.

“We also know that the particles do not need to get into the baby’s body to have an adverse effect, because if they have an effect on the placenta, this will have a direct impact on the foetus,” Dr Liu cautions, however.

The results support previous findings that women living in polluted cities are more prone to pregnancy issues. Furthermore, they suggest that such issues — especially low birth weight — can still happen at pollution levels that are lower than the EU’s recommended annual limit.

The study “Do inhaled carbonaceous particles translocate from the lung to the placenta?” has been presented at the European Respiratory Society International Congress in Paris on September 16th. The work is a non-peer reviewed observational study.

Horned Larks from The Field Museum's collections,. On the left row you can see gray birds from the turn of the century and cleaner birds from more recent years on the right. Credit: The University of Chicago and The Field Museum.

How dirty, soot-covered birds can track down pollution over a whole century

We often complain about the horrid levels of pollution, but you also have to understand that things were far worse not too long ago. At the height of the steel boom a hundred years ago, the sky above Chicago and Pittsburgh was as grey and obscured as that in Beijing or New Delhi today. This history of soot and smoke can be retraced using a surprising proxy, as scientists working at The Field Museum and the University of Chicago recently demonstrated. Their work showed that levels of soot preserved on the feathers of songbirds collected over the last 135 years closely follow the levels of soot in the air over cities in the Rust Belt.

Horned Larks from The Field Museum's collections,. On the left row you can see gray birds from the turn of the century and cleaner birds from more recent years on the right. Credit: The University of Chicago and The Field Museum.

Horned Larks from The Field Museum’s collections. On the left row, you can see gray birds from the turn of the century and cleaner birds from more recent years on the right. Credit: The University of Chicago and The Field Museum.

Horned Larks (Eremophila alpestris), the songbirds in question, can be frequently found across the northern hemisphere. If you have a keen eye, especially during the winter, you might be pleasantly surprised to meet the gaze of a neat yellow face, with black mask and tiny black “horns”, waving in the breeze. The bird’s cute yellow face and white belly were unrecognizable a century ago, though. As the birds dashed through the smoke-covered sky above the industrialized cities of the Rust Belt, the larks essentially acted like filters, becoming covered in soot, tail to beak.

The feather dusters

Shane DuBay and Carl Fuldner, both graduate students at The Field Museum and the University of Chicago, analyzed over a thousand birds housed in the museum’s collection, which included all five species that breed in the ‘Manufacturing Belt’. They had a hunch they could correlate the ‘dirty’ specimens with atmospheric soot levels, since ornithologists at The Field Museum had always noted that early 1900s birds were visibly darker than they should have been.

“When you touch these birds, you get traces of soot on your hands. We’d wear white gloves while handling them, and the gloves would come away stained, like when you get ink on your fingertips reading a newspaper,” says DuBay. “These birds were acting as air filters moving through the environment,” adds DuBay.

Just like you’d use a feather duster to brush off soot near a fireplace, so did the bird’s feathers cling to the deep black flaky substance as they flew about. Because they molt and grew a set of new feathers each year, the birds proved to be an ideal candidate for measuring soot deposition over the span of a year. Interestingly, older birds were always dirtier than younger ones.

Field Sparrows from The Field Museum's collection. Credit: The University of Chicago and The Field Museum.

Field Sparrows from The Field Museum’s collection. Credit: The University of Chicago and The Field Museum.

To measure sootiness over the century, the pair of researchers employed a novel approach. Instead of counting soot particles or some other laborious technique, the team photographed each specimen and then measured the light reflected off of them. They had the help of a photo historian specialized on environmental photography to develop the right technique.

You can plainly see the dramatic contrast between soiled gray birds and the pristine ones in some of the images embedded in this article. But DuBay and Fuldner went a step further and plotted the amount of light bouncing off the feathers with the year the birds were collected. The higher the sootiness, the less light was reflected. They then correlated the results with historical records of urban air pollution and found there was more soot in the atmosphere than previously thought. Black carbon has a significant effect on the climate and scientists could use this new information to improve their models.

“The changes in the birds reflect efforts, first at the city level but eventually growing into a national movement, to address the smoke problem,” says Fuldner. “We are actually able to go back and see how effective certain policy approaches were.”

“We were surprised by the precision we were able to achieve,” says DuBay. “The soot on the birds closely tracks the use of coal over time. During the Great Depression, there’s a sharp drop in black carbon on the birds because coal consumption dropped—once we saw that, it clicked.” The amount of soot on the birds rebounded around World War II, when wartime manufacturing drove up coal use, and dropped off quickly after the war, around when people in the Rust Belt began heating their homes with natural gas piped in from the West rather than with coal.

Soiled and clean Horned Larks closeup. Credit: The University of Chicago and The Field Museum.

Soiled and clean Horned Larks closeup. Credit: The University of Chicago and The Field Museum.

Does this mean that American air is a lot cleaner because our birds are also clean? Not so fast, DuBay says. There’s far less black carbon that reaches the atmosphere over U.S. soil, that’s for sure, as evidenced by the numerous closed-off coal mines and power stations. Still, there are some cities where heavy soot chokes the air, endangering the safety of people and wildlife. But what’s more, there are now new, less-conspicuous pollutants that can jeopardize human health, despite the sky might not be clogged.

It’s interesting to note, however, how a clever use of proxies can reveal so much about our history of fossil fuel use. For instance, the study shows there was a tipping point when America moved away from burning that much coal. Right now, we’re nearing another tipping point where we’ll ditch fossil fuels for good in favor clean renewable energy. It’s a matter of ‘when’, not ‘if’.

“As a historian, one of the questions I always ask is, ‘What is the point of this research to the way we live now?’ In this case the answer quickly became clear,” says Fuldner. “Filling in a blank space in the historical record of something as large as air pollution in American cities, and being able to share that with atmospheric scientists who study the effects of black carbon on the climate, is extraordinary.”

Scientific reference: Shane G. DuBay el al., “Bird specimens track 135 years of atmospheric black carbon and environmental policy,” PNAS (2017) 

Air pollution much more dangerous than climate change for global agriculture

Scientists have long known that climate change has a major negative impact on global agriculture, potentially even threatening global food security. But a new research shows that air pollution is actually much more threatening. Anthropogenic climate change caused 3.5% decrease in potential wheat yield on a country level in India; air pollution caused more than 32% decrease in potential yield.

Ozone and soot

Relative wheat yield changes, India, 1980-2010. Burney & Ramanathan

Air pollution and soot are the main culprits for crops, with some states in India suffering from a 50% reduction in yields, and the odds are the same is happening in many parts of the world (at the same or at a smaller scale). Jennifer Burney and Veerabhadran Ramanathan from the University of California, San Diego systematically investigated the impact of air pollution and anthropogenic climate change on crops in India and found that on average, air pollution has caused a third of loss in wheat yield and one fifth of loss in rice yield in India in 2010, compared to a baseline from 1980.

Many previous papers have studied the impact of climate change in agriculture, and for good reason. A change as slight as one degree Celsius can spell disaster for cultures across the world. But according to this research, ozone and soot causes much more crop loss than climate change. From 1980 to 2010, the increase in temperature and change in precipitation as a result of anthropogenic climate change has caused a 3.5% decrease in wheat yield, while the above mentioned elements had a negative contribution of 32%.

Air pollution is harming India’s wheat farmers. EPA

Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. However, it’s this exact property which also makes it a pollutant, damaging not only human tissues, but also plant tissues. Soot is emitted mainly from burning plants and fossil fuels. It directly absorbs sunlight, reducing the amount of light available for crops to photosynthesise. Each of these two factors alone has caused more damage to crops than global warming.

The effects of ozone on soybeans. NASA

Bad news and good news

This is, of course, bad news, especially as things aren’t going to get any better anytime soon. William Bloss, an expert in atmospheric chemistry, points out that background ozone levels have more than tripled since they were first monitored in the 1870s.

“Looking to the future”, he says, “models predict that ground level ozone will continue to rise in many areas of the world”. Ozone pollution will continue to be a major challenge for food security.

The good news is that if there is a desire to change things, the effects will be immediate. Air pollution (soot and ground level ozone) is short lived and immediate benefits can be seen as soon as action is taken – as opposed to carbon dioxide, which has much longer effects. This also means that there is a very strong incentive to address this type of pollution, and hopefully, policymakers will not turn a blind eye towards this.

Another noteworthy thing is that there were significant variations in the damage caused by soot. Some areas in India had a yield loss of over 50% which raises some important questions: Could the air pollution in China be causing the major increase in recent global food demand? Personally, I’d really love to see the same type of study conducted in China and other areas of the world.

Journal Reference: Jennifer Burneya and V. Ramanathanb. Recent climate and air pollution impacts on Indian agriculture. doi: 10.1073/pnas.1317275111

A: The estuaries of the Ob' and Yenisei Rivers. B: The Lena River delta.

Alarmingly high mercury concentrations in the Arctic might be due to Siberian rivers

Besides ever thinning ice, permafrost melting, soot deposits, habitat loss, you might as well add another significant factor threatening the arctic ecosystem – mercury. For some time, the alarmingly high mercury concentrations in the regions were rather unaccounted for, in part, however a new research by scientists at Harvard’s Atmospheric Chemistry Modeling Group suggests that three Siberian rivers might be to blame.

The Lena, the Ob, and the Yenisei all flow north of Siberia and flush in the Arctic Ocean every spring after the ice formed through the winter melts. Environmental experts have assumed that the mercury gets up to high latitudes through the atmosphere, but a more in depth look showed that this explanation doesn’t stand.  Mercury levels tend to peak in the Arctic atmosphere in summer, but power-plant emissions are also highest in summer, when air conditioning sends the demand for electricity soaring. “It didn’t make sense,” said the study’s lead author, Jenny Fisher, a postdoctoral fellow with Harvard’s Atmospheric Chemistry Modeling Group in an interview. Mercury takes time for it to make its way north.

A: The estuaries of the Ob' and Yenisei Rivers. B: The Lena River delta.

A: The estuaries of the Ob' and Yenisei Rivers. B: The Lena River delta.

Mercury is a highly toxic substance, which severely affects the local ecosystem through food-chain poisoning. The substance doesn’t break down, and gets transferred as bigger animals eat smaller animals, from plankton, to seal, to polar bears, to the local Inuit population.

“The only thing that had the right signature is rivers,” Fisher said. Ice melting in the spring perfectly coincide with the mercury spikes in the Arctic. With ice cover melting back in the ocean as well, the mercury is free to enter the atmosphere, boosting concentrations far higher than they’d otherwise be. In fact, twice as much mercury comes from Siberian rivers as comes from northward-drifting air, the researchers found.

Possible source for the mercury outbreaks in the Siberian rivers might be local Russian mining operations, naturally occurring mercury leaching of the soil where it’s been frozen in place for tens of thousands of years due to permafrost melting, and even an alteration of the hydrologic cycle due to global warming.

It’s still just a hypothesis, Fisher said. “We really have limited knowledge of what’s really going on, and we’re hoping this work inspires more research. But it may be,” she said, “that climate change affects the Arctic in more ways than we thought.”

source: Climate Central

Simple, cheap measures could reduce global warming and save many lives

An international team of scientists showed that simple, inexpensive measures to cut emissions of two common pollutants will significantly slow global warming, boost crop production throughout the world and save many lives in the process.

The climate change debate is traditionally centered around carbon dioxide emissions – one of the major problems and causes of the greenhouse effect which leads to global warming. But this team of scientists found that two lesser known pollutants, methane and soot, also have a significant negative impact on the environment – and unlike carbon dioxide, this could easily be improved.

Slashing emissions of these harbringers of global warming would be non-expensive, and would bring a win-win-win situation, explained NASA climate scientist Drew Shindell, who led the study appearing in the journal Science.

“Even if you don’t believe climate change is a problem, these things are worth doing.”

Previous studies have often hinted at the benefits cutting down these emissions would bring, but this study analyzed 400 actions policymakers could take. Out of these possible measures, even only 14 could bring massive, advantages.

“They’re all things we know how to do and have done; we just haven’t done them worldwide,” said Shindell, who works at the NASA Goddard Institute for Space Studies in New York.

Of course, applying these measures even locally would be a challenge; globally – it seems like a Herculean task, even though the ultimate benefit dwarfs the cost.

Reducing methane and soot would slow global warming dramatically, by over one degree Fahrenheit by the middle of the century, according to computer simulations the team conducted. At the same time, improving the air quality would prevent numerous lung and cardiovascular diseases, saving anywhere 700.000 and 4.7 million lives annually. Also, crops would have a much easier time absorbing their nutrients without these pollutants in the air, and global crop yields would rise by 30 to 135 metric tons each year.

“In the absence of a global carbon dioxide agreement, it makes sense to move ahead on global efforts to reduce these other gases,” said Joyce Penner of the University of Michigan, who has studied the climate impacts of soot but was not involved in the new research.

It is estimated that 3 billion people, almost half the world’s population relies on burning wood, dung, or other fuels that eject soot into the atmosphere – soot particles fall from the air in less than a week. Hopefully, even though implementing such measures worldwide seems utopian, perhaps we would see them at least in some areas of the world.

The yellow line depicts the artic ice surface level from the past 30 year average. The red line represents opened up Northwest Passage shipping lanes. (c) NASA Goddard's Scientific Visualization Studio

Melting polar ice makes way for new shipping routes

The yellow line depicts the artic ice surface level from the past 30 year average. The red line represents opened up Northwest Passage shipping lanes. (c) NASA Goddard's Scientific Visualization Studio

The yellow line depicts the artic ice surface level from the past 30 year average. The red line represents opened up Northwest Passage shipping lanes. (c) NASA Goddard's Scientific Visualization Studio

Record low ice volumes in the arctic caused by global warming have been reported this year, and if there are still some climate skeptics among you, recent events concerning trading in the region might provide proof enough of dramatic change. Supertankers and giant cargo ships could next year travel regularly between the Atlantic and Pacific Oceans via the Arctic, after provisional new opened trading routes, which trace spots not too long ago inaccessible, that shorten the travel time to as much as half.

While that’s potentially bad news for our environment, it’s great news for shippers in the Northern Hemisphere. This year’s record low opened up shipping passages through the Northwest Passage and Northern Sea for brief periods last month. Thus, on the northern trade route a medium-sized bulk carrier could need only 18 days and 580 tonnes of bunker fuel on a journey between northern Norway and China. The voyage would normally take upwards of 40 days.

Climate change turns to profit

Shorter voyages and lower fuel consumptions means a sturdy increase in profits for the northern hemisphere trading companies. Danish shipping company Nordic Bulk Carriers took full advantage of the new routes, and claimed to save one third of its usual shipping costs by taking shorter shipping routes to China through the Arctic.

Actually, the Russian prime minister, Vladimir Putin, came out last week and predicted that the route would soon rival the Suez canal as a quicker trade link from Europe to Asia. “The Northern sea route will rival traditional trade lanes in service fees, security and quality,” he told a conference organized by the Russian Geographical Society in Arkhangelsk in September.

Climate activists view this latest route as clear evidence of climate change, and while they accept that ships would burn less fuel and emit less CO2, they fear oil spills and other maritime accidents, as well as “black carbon”, the sooty residue of partly burned fuel which is deposited on ice and is a short-lived but powerful “forcer” of climate change.

Sea ice extent is expected to decline until Arctic summers are ice-free, researchers have predicted.

sea level increase

Sea level rise of up to 1.6 meters projected for 2100

sea level increase

It is no longer a question if multi-meter sea level rises will happen, but only of when. According to the latest estimate from the Arctic Monitoring and Assessment Programme it seems the accelerated climate change in the Arctic including a thaw of Greenland’s ice could raise world sea levels by up to 1.6 meters by 2100.

“The past six years (until 2010) have been the warmest period ever recorded in the Arctic,” according to the Oslo-based Arctic Monitoring and Assessment Programme (AMAP), which is backed by the eight-nation Arctic Council.

“In the future, global sea level is projected to rise by 0.9 meters (2ft 11in) to 1.6 meters (5ft 3in) by 2100 and the loss of ice from Arctic glaciers, ice caps and the Greenland ice sheet will make a substantial contribution,” it said. The rises were projected from 1990 levels.

“Arctic glaciers, ice caps and the Greenland ice sheet contributed over 40 percent of the global sea level rise of around 3 mm per year observed between 2003 and 2008,” it said.

Back in 2007 the United Nations’ Intergovernmental Panel on Climate Change (IPCC) reported that they estimate an increase of sea levels between 18 and 59 cm by 2100, however these conservative numbers did not take in consideration the drastic acceleration of thaw in the arctic.

“It is worrying that the most recent science points to much higher sea level rise than we have been expecting until now,” European Climate Commissioner Connie Hedegaard told Reuters.

“The study is yet another reminder of how pressing it has become to tackle climate change, although this urgency is not always evident neither in the public debate nor from the pace in the international negotiations,” she said.

The UN is currently in entangling talks on how they can battle the increase in temperature and sea levels, but progress is sluggish described at best. But the climate doesn’t wait, actually it’s said the Arctic Ocean could be nearly ice free in summers within 30 to 40 years, earlier than projected by the IPCC.

RELATED: Soot responsible for rapid Arctic melting?

As reflective ice and snow shrink, ever bigger areas of darker water or soil get exposed filled with black carbon or soot. Those dark regions are extremely dangerous for the polar caps, as they soak up ever more heat from the sun, in turn stoking a melt of the remaining ice and snow.

“There is evidence that two components of the Arctic cryosphere — snow and sea ice — are interacting with the climate system to accelerate warming,” th IPCC said.

The AMAP report was due for release on Wednesday but AMAP officials released it a day early after advance media leaks.

An international research team is exploring the Arctic in search of soot. Carbon deposited there as a result of activities elsewhere can have a long-term impact on climate. (Associated Press)

Soot responsible for rapid Arctic melting?

An international research team is exploring the Arctic in search of soot. Carbon deposited there as a result of activities elsewhere can have a long-term impact on climate.  (Associated Press)

An international research team is exploring the Arctic in search of soot. Carbon deposited there as a result of activities elsewhere can have a long-term impact on climate. (Associated Press)

An international research team is in the land of snow and ice, in search of soot or black carbon, in an effort to judge whether or not it is responsible for the alarming rapid warming in the area lately. The research team includes scientists from Norway, Russia, Germany, Italy, and China, whose members are working from Norwegian islands inside the Arctic Circle, about halfway between Norway and the North Pole.

Scientists believe a thin layer of soot is causing the Arctic caps to absorb more heat, which is produced by vehicle engines, aircraft emissions, burning forests and wood- and coal-burning stoves.

“Carbon is dark in color and absorbs solar radiation, much like wearing a black shirt on a sunny day. If you want to be cooler, you would wear a light-colored shirt that would reflect the sun’s warmth,” said Tim Bates, a research chemist at NOAA’s Pacific Marine Environmental Laboratory (PMEL) in Seattle and co-lead of the U.S. component of the study.

“When black carbon covers snow and ice, the radiation is absorbed, much like that black shirt, instead of being reflected back into the atmosphere,” explained Bates.

The study’s goals are to coordinate more than a dozen research activities so they are done in tandem providing, for the first time, a vertical profile of black carbon’s movement through the atmosphere, its deposition on snow and ice surfaces, and its affect on warming in the Arctic.

“The Arctic serves as the air conditioner of the planet,” said Patricia Quinn of the National Oceanic and Atmospheric Administration (NOAA), and research chemist at Pacific Marine Environmental Laboratory (PMEL).

Heat from across the world moves towards the Arctic through air and water and at least some of that can radiate into space.  This is while the ice and snow reflect the sun’s incoming heat to other parts of the Earth, making the poles cooling systems for the planet. Soot, however, could prove to be an extremely dangerous phenomenon.

In recent years, the Arctic has been warming more rapidly than other areas of the planet, a lot faster actually since over the past 100 years, the Arctic surface air temperature has increased twice as fast as the global average. It’s important to note that the “warming of the Arctic has implications not just for polar bears, but for the entire planet,” Quinn told the Associated Press (AP).

Authors of the study believe the Arctic warming would implicate the entire planet and that cutting carbon dioxide and other greenhouse gases would effectively resolve the issue.  However, studies say that reducing the amount of short-lived pollutants, like soot, would be faster since greenhouse gases live much longer in the atmosphere.

The Norway research will continue through mid-May. The teams then will spend months analyzing their data and report the results at scientific meetings and in journals in the near future.

Fighting against soot – more important than ever

Most of the talk about global warming revolves around carbon dioxide, sometimes giving the false impression that it alone is responsible for global warming and all its implications. However, numerous studies have revealed a new enemy, one almost as dangerous as carbon dioxide: soot.


The black powdery pollutant is responsible for numerous climatic shifts, especially in the areas between the tropics. The main difference however, is that soot can be relatively very easy ‘defeated’. Soot, generally called black carbon by climatologists, originates mostly from power plants, diesel engines and activities mostly related with developing countries (burning the fields or open cooking stoves, for example).

What happens is that as it drifts into the atmosphere, soot attracts a lot of sunlight and heat, warms up and then radiates heat; it can do the same thing on the ground too. Changing pollution trends have affected the way it manifests, and for the worst. Until recently, soot was generally mixed with sulfate particles that reflected sunlight. However, the mix of sulfate and soot produces new particles that have an even greater ability of absorbing sunlight.

“That actually enhances the effect,” says Mark Jacobson, a Stanford University atmospheric scientist. “It can double the warming.”

There are still many things researchers have been unable to assess, but one thing’s for sure: at least in the Northern Hemisphere, soot has caused some dramatic changes. The thing is that unlike greenhouse gases that quickly disperse in the atmosphere, soot congregates above and stays there. Here’s what Al Gore says:

“A new understanding is emerging of soot. Black carbon is settling in the Himalayas. The air pollution levels in the upper Himalayas are now similar to those in Los Angeles.”, and he’s right.