Saturday, 24 July 2010
The final common pathway of metals and particulates (oxidative stress),allergens (asthma) and gases (noxes and ozone).The picture above shows leakage,the black lines, into inflammed tissues
Most people think of inflammation as a small red painful itchy lump, or a swollen knee or ankle. They think of it as local. A real flu gives a hint at how it can be a whole body response. You won’t hear about this in relation to air pollution from the newspapers, TV, parliament or government bodies. Plausible deniability is one of the reasons for “not knowing” why the body’s rhythms of inflammation make a nonsense of the way averages of pollution, and the general numbers game, are played out in London. Self-amplifying cascades are the order of the day. A single peak episode will trigger an unstoppable, uncontrollable immune reaction leaving the whole body more sensitive to the next lot of pollution and awash with activated cells, new cells breeding fast and swamped with little known hormones, some of which stay around for 24 hours or longer. When this pollution becomes long term, or when we have a long heat wave this gets really serious and leads to permanent scarring and damage. If a child has lived long enough in such conditions the lungs never grow properly, the wounded lungs scarring, if it is in the womb its development is affected.Low birth weight,preterm delivery and therefor infant mortality all rise in frequency. Most politicians prefer to talk about the end stage, dying early, rather than the damage that affects babies or youngsters for their whole life ahead.
Inflammation 1 the horrible hidden hormones
These substances are not made by distinct, specialised glands, but by a variety of cells (see inflammation 2). The great majority of their actions are on site. In some cases they circulate in the blood to exert hormonal effects on distant organs and tissues involved on our defences, and also on the guerrilla army of cells that have moved from the blood into places like the brain, gut, heart and placenta to lie in wait for infection and ambush any viruses or bacteria.
a) cytokines (over a hundred), the interleukins
e) Products of blood clotting
h) Lysosomal enzymes and nitric oxide
You get the picture, you probably haven’t heard of many of these…but I haven’t made them up. A completely up to date textbook would list more, show up more connections, describe a bigger circulation.
If ordinary hormones are the long range parcel service, then cytokines start out as notes from next door neighbours, except that they are a windswept snowstorm of paper, of many colours.
They were the killers in Spanish Flu, and create the final stage of lethal Bird Flu. We need them to fight viruses and bacteria, and heal cuts and stings, but when they are switched on by the wrong things, or get too active, they get too damaging.
When the amounts are too high they stop being local (microscopic distances) and go global. They hang around for many hours, some for days others for weeks. They leave the lungs ready to react faster and more intensely to the next lot of pollution. This makes such biological nonsense of the common number averages used in counting pollution. Their switch is on/off, and gets more sensitive as the day goes on *see the nox/ozone graphs of lethal London levels.
Inflammation 2 the the cells that try too hard, sometimes
Neutrophils chomp, send messages to dilate blood vessels and make them leaky
Basophils like mast cells,but in the blood, release histamine,a potent chemical
Eosinophils special parasite killers, and mediate allergic reactions
Monocytes…munchers,killer chemical secretors….move out of blood into all tissues, to become the guerrilla army
Lymphocytes…..memory recognition cells
B cells …start an antibody response
Plasma cells…..make antibodies
Macrophages (including the brain microglia), munchers,chemical killers,rubbish processors helping T cells learn what rubbish is
Mast cells release histamine and other chemicals in an on/off burst….anaphyllactic shock is when all their fireworks go off at once.
In the bloodstream there are a number of specialist white cells…recognition scouts, dispatch riders, memory cells and heavyweight munchers. They send orders and messages to each other, and when things get too hot their messages are carried to everywhere in the body (going global).Munchers are good at digesting bugs and worn out cells,they clean up stuff. But when its soot, or coal dust, or asbestos, or cigarette smoke or rock dust or fibreglass, or particulates, they just can’t…so they die….and their neighbours get the message to clean things up, eat the rubbish (literally), and fail again….
Once you see a smokers lung at post mortem, you never forget it. We have taken action against passive smoking…but not against air pollution to anything like the same extent.
Inflammation 3 Chronic Inflammation and Scarring,
(top) brain chronic inflammatory changes
(bottom) lung with spaces where air used to flow (arrowheads),scar tissue (arrows) and collections of white cells (star)
Lung, Brain, Heart and Placenta.
If the inflammation is bad enough or frequent enough the white cells and their messages can “reach the parts other beers cannot reach”, switch on their cousins in the brain, heart ( where lung blood reaches first) and womb. Probably lots of other places that have not been studied yet as well.
The wound healing part of inflammation takes place, and microscopic scarring, like any scars you have that you can see on your skin, but inside.
Wednesday, 21 July 2010
OZONE LEVELS PEAK IN THE HEAT
Lethal London Ozone levels have been recorded over the last few days, in the current heatwave.
The government, via DEFRA, love to blame the “foreign” transboundary air flowing from the industrial areas of Northern Europe…and see no reason to change transport policy here. They say only winds from the east cause pollution.
Since Monday 19th July 2010, the winds have been SW-SSW, and temperatures 28-29 degrees centigrade…..so the levels in London, shown above, are all our own work !!!
100 = 5% DAILY MORTALITY INCREASE
150 = 8%
180-190 = 10% DAILY DEATHS MOVE UP!
200 people a day die in London on an average day, so that's an extra 10, 12,16 or 20
A DAY...EVERY DAY THE LEVELS ARE HIGH
The average death rate for people over 55 (the elderly are much more at risk here) can go up from 9/100,000 to 20/100,000 in extended heatwaves....where ozone and temeperature combine.
For a fixed temeperature...the higher the ozone, the more die
For a fixed ozone level.... the higher the temperature the more die
The death rates are much higher amongst the working class in all cases.
Wednesday, 7 July 2010
Tuesday, 8 June 2010
Inhaled pollutants may inflame more than the lungs
By Janet Raloff
May 22nd, 2010; Vol.177 #11 (p. 16)
Destination brain :Tiny inhaled motes can travel beyond the lungs; new research suggests these particles may ravage the brain.
When Lilian Calderón-Garcidueñas recruited children for a study probing the effects of air pollution, Ana was just 7. The trim girl with an above-average IQ of 113 “was bright, very beautiful and clinically healthy,” the physician and toxicologist recalls.
But now Ana (not her real name) is 11. And after putting her and 54 other children from a middle-class area of Mexico City through a new battery of medical and cognitive tests, Calderón-Garcidueñas found that something has been ravaging the youngsters’ lungs, hearts — and, especially troubling, their minds.
Brain scans and screening for chemical biomarkers in the blood pointed to inflammation affecting all parts of the brain, says Calderón-Garcidueñas, of the National Institute of Pediatrics in Mexico City and the University of Montana in Missoula. On MRI scans, white spots showed up in the prefrontal cortex. In the elderly, she says, such brain lesions tend to denote reduced blood flow and often show up in people who are developing dementias, including Alzheimer’s disease.
In autopsies of seemingly healthy Mexico City children who had died in auto accidents or other traumatic events, Calderón-Garcidueñas uncovered brain deposits of amyloid-beta and alpha-synuclein, proteins that serve as hallmarks of Alzheimer’s and Parkinson’s diseases. Several years earlier, she had found similar abnormalities in homeless Mexico City dogs and exaggerated versions of the abnormalities in local 20- to 50-year-olds.
She has published studies linking the insidious changes to the metro region’s air quality. The area’s 20-plus million inhabitants make it one of the world’s largest megacities, a roughly 7,000-square-kilometer region choking with smog and particles containing carbon, metals and more (SN: 9/8/07, p. 152). Most are nanoparticles — too small to see but just the right size to migrate into tissues throughout the body. Further clouding the air are solvents and other reactive gases — as well as toxins contributed by livestock feces.
Scientists have known that air pollution can impair airways and blood vessels. The emerging surprise is what it might do to the brain. Increasingly, studies have been highlighting inflammation-provoking nanopollutants as a potential source of nerve cell damage.
Calderón-Garcidueñas has been correlating Mexico City’s stew of air pollutants with a suite of symptoms in people of all ages. In March in Salt Lake City at the annual meeting of the Society of Toxicology, Calderón-Garcidueñas unveiled some of her latest data. At age 11, Ana shows persistent, growing brain lesions, the toxicologist reported. As do the other Mexico City children surveyed. They also exhibit cognitive impairments in memory, problem solving and judgment and deficiencies in their sense of smell compared with age-matched children from a cleaner city 120 kilometers away.
Metals in the air Particles collected from the air above Mexico City (two shown) contain metals including manganese, iron, zinc, tin, lead and mercury (labeled). New research suggests that the particles can end up in the brain.Kouji Adachi and Peter R. Buseck/Environmental Sci. Technol. 2010
Other toxicologists at the meeting presented data, largely from animal studies, tracking the movement of billionth-of-a-meter–scale particles into the brain, where they triggered inflammation and abnormalities characteristic of Alzheimer’s or Parkinson’s.
Until recently, most air pollution toxicology has focused on impacts to the lungs and heart, observes James Antonini of the National Institute for Occupational Safety and Health’s lab in Morgantown, W. Va. The challenge now, he says, is to identify which pollutants are harming the nervous systems of Ana and others who live in areas with particularly dirty air.
Mexico City is not the only source of real-world pollution that has been linked to mental impairments.
Ulrich Ranft and colleagues at the Environmental Health Research Institute at Heinrich Heine University in Düsseldorf, Germany, studied 400 or so highly functioning local women in their mid- to late 70s. Elderly women who lived within 50 meters of very busy streets exhibited poorer memory skills than did women of the same age whose homes were well removed from highly trafficked roadways, the team reported in the November 2009 Environmental Research.
The study turned up no similar link between cognitive scores and average levels of particles in the women’s communities. That makes sense, Ranft says, because the levels of ultrafine motes emitted by traffic can be quite high along streets, “but drop off very fast, falling to almost background levels when you get just 100 meters away from the road.”
Young children’s minds may be especially sensitive to tiny airborne particles spewed by traffic, according to Shakira Franco Suglia of the Harvard School of Public Health in Boston and her colleagues. In studies of roughly 200 Boston 10-year-olds, the researchers found that those living in areas with the highest average airborne concentrations of soot, a pollutant primarily associated with traffic, had lower IQs and lower scores on memory tests.
From nostril to brain
The team divided the kids by exposure levels into four groups. The average IQ drop between one group and the next averaged about three points — comparable to that seen in kids whose mothers had smoked during pregnancy, Franco Suglia’s group reported in 2008 in the American Journal of Epidemiology.
Taking note of non-scents
A few studies, including the recent one by Ranft’s group, have also observed a somewhat impaired sense of smell among people living in polluted regions.
At the toxicology meeting, Calderón-Garcidueñas reported that kids and young adults in Mexico City have a somewhat worse sense of smell than those living in cleaner cities. Roberto Lucchini of the University of Brescia in Italy reported much the same for adolescents living in communities around now-closed iron-alloy manufacturing plants. Both groups’ data also turned up signs the youngsters have been experiencing at least subtle nerve damage.
The findings, the researchers say, are especially worrisome since a number of studies have shown that a sense of scents wanes in people developing Alzheimer’s and Parkinson’s.
Though metal pollution hasn’t been confirmed as a cause of these diseases, Lucchini was able to link pollution in Brescia to reduced smelling abilities and to motor impairments.
Until 2001, alloy plants in northern areas of the province spewed a number of metals into the air. Manganese remains a substantial pollutant in the air, soil and house dust in this part of Italy. Work by Lucchini’s team uncovered unusually high rates of symptoms including tremors, slowed movement and rigidity among adults living near the now-defunct plants. The local prevalence of these and other Parkinson’s-like symptoms is about 400 per 100,000 inhabitants. That’s two and a half times the usual rate in Italy.
Unnerving signs: Diffuse amyloid plaques (brown blotches), like those seen in Alzheimer's patients (top), have shown up in adults (middle) and children (bottom) from Mexico City. L. Calderon-Garciduenas
Lucchini’s team, which had already planned to examine 300 middle schoolers for neural effects of local pollution, included a smell assay in the tests. To measure exposures, the researchers collected blood and urine from the 11- to 13-year-olds. A third of the kids also carried a backpack fitted with an air-sampling device and a GPS to pair up readings and precise locations. Some children lived near the former alloy plants, others at Garda Lake, a relatively clean comparison region in the province.
At the toxicology meeting, Lucchini reported that among kids living near the alloy plants, “Odor identification was clearly impaired compared to children living in the [Garda Lake] region.” The smell-threshold reduction was “preclinical,” he explains, meaning the children wouldn’t notice the change but it could be picked up with testing.
His team also linked exposures to manganese-rich dust particles with motor impairments — such as a reduction in the speed at which children could clench their hands or sequentially touch the fingers of each hand to the thumb. Though it’s too early to speculate about whether the symptoms will evolve into something resembling Parkinson’s disease, Lucchini says, these are the first data to link such motor impairments to inhaled manganese.
Nosing out the problem
While these data are just coming in, a growing body of evidence suggests that nerves in the nose can provide a highway along which some inflammatory pollutants, such as metals, motor directly from the outside world to the brain.
How efficient the conduit is varies by pollutant particle, according to new experiments by Wolfgang Kreyling of the Helmholtz Center and the German Research Center for Environmental Health in Munich. In rats, 20-nano-meter–diameter agglomerations of at least 100 radioactively labeled iridium particles entered the brain whether inhaled through the nose or pumped directly into the lungs.
By comparing what has been deposited after one-hour exposures via the two routes, Kreyling’s team showed that for such small particles, two-thirds of what ends up in the rat brain comes directly from the nose, the rest via a more circuitous route that starts in the lungs, moves into the bloodstream and then goes to the brain.
Well under 1 percent of inhaled particles made it to the brain via either route, Kreyling reported at the toxicology meeting. However, he added, once those insoluble particles arrive in the brain, “we do not see much clearance.” So continuous exposure over time could leave substantial amounts of inflammatory particles in the brain, he speculates.
Change the 20-nanometer iridium to same-sized soot particles and the uptake rate falls by 75 percent. Expose animals to 20-nanometer particles made from titanium dioxide or to 80-nanometer particles of iridium, and the rate of brain uptake drops by about 90 percent.
But no one’s sure how well such studies model what happens in people, points out David Dorman of North Carolina State University in Raleigh. Long-snouted rodents depend far more than humans do on the sense of smell and have evolved a much bigger and more efficient system linking the outside environment to the brain. For instance, Dorman notes that half of the nasal cavity of a rat is lined with olfactory-system cells. In humans, this receptive area is much smaller, he says — “only about 3 to 5 percent.”
His team has shown that even for particles that begin moving up the olfactory highway, some stop partway. One type that does seem to go the distance: manganese. When Dorman’s group exposed rats to manganese, the same metal that taints the dust Lucchini has been studying in Italy, nearly all of the pollutant particles entering the nasal tissue migrated at least as far as the olfactory bulb, a structure in the brain.
Regardless of what percentage of particles make it all the way, such data suggest that inhaled airborne motes can enter the brain, where they would be expected to foster inflammation, a primary underlying trigger of tissue damage and neurodegenerative disease.
Moreover, Calderón-Garcidueñas has linked the pollutants with a breakdown in the lining of the nose, which could facilitate particles’ access to olfactory highways serving the brain.
A burning issue
Although the source and chemistry of air pollutants affecting the brain differ, all seem to share the same toxic modus operandi: inflammation. Some pollutants turn on genes that release inflammatory chemicals, others call out immune cells that quash invaders and clean up trash using inflammatory mechanisms. Still more induce biologically destructive electron-stripping chemical reactions that won’t quiet down without a copious release of antioxidants.
Krishnan Sriram, a neurotoxicologist with NIOSH, reported at the toxicology meeting that following 10-day and 28-week exposures to manganese welding-fume particles, rodents developed brain changes resembling many of those in Parkinson’s patients — nerve-cell inflammation, tissue damage from oxidation and loss of nerve cells from a region of the brain that makes dopamine.
In addition, his team looked at some of the family of Park genes; mutations in these genes are associated with an elevated risk of developing Parkinson’s disease. In rodents exposed to manganese, the researchers saw a reduction in the genes’ production of proteins that normally help rid the body of misshapen nerves and that quash the oxidation responsible for excessive inflammation.
Bellina Veronesi of the U.S. Environmental Protection Agency and Lung-Chi Chen of the New York University School of Medicine laboratory in Tuxedo reported data at the toxicology meeting from mice exposed to dense concentrations of pollutants collected from outdoor air. Animals without functioning apolipoprotein genes, which normally help control the production and activity of certain fats in the bloodstream, experienced runaway brain inflammation and nerve damage. This finding suggests that properly working apolipoproteins may be essential for coping with tiny inhaled particles.
People born with a particular apolipoprotein gene variant — known as APOE-4 — face a greatly elevated risk of developing late-onset Alzheimer’s disease and more general cognitive declines. In North America, Calderón-Garcidueñas says, roughly one-fifth of people carry this variant. And in Mexico City, she has found that children and young adults with the variant exhibit the most inflammation, the greatest cognitive declines and the most rapid deposition of amyloid-beta.
But Calderón-Garcidueñas has yet to prove that deposition in the brain of air particles primarily explains the brain inflammation she’s measured, says Dorman. One has to wonder, he says, whether the “widespread nasal damage” that she depicted was a major contributor to inflammatory brain damage or independent of it.
Calderón-Garcidueñas is aware of the issue. She notes that work by others has shown that inflammation-provoking cells or chemicals have the potential to migrate from distant sites into the brain, triggering fallout damage there.