Breathing Toxic Air

Fossil fuels' days are numbered. That's a good thing given the toll that burning coal and oil takes on our climate and health. 

But especially for the people of Beijing -- and Delhi and Tehran, among other cities currently choking on dirty emissions -- that final goodbye can't come soon enough.

The images are hard to miss and harder to ignore: women, men, children and even pets enveloped in an almost tangible haze, forced to wear face masks as they go about their daily lives -- bicycling, shopping, getting married.

The statistics are equally alarming: More than 4,000 Chinese die daily from air pollution. And that figure may even be an underestimate, as pollution levels have risen since researchers crunched those numbers earlier this year.

A tragedy is indeed unfolding, and threatening to escalate.

On multiple days this December, the air in Beijing measured at least 20 times dirtier than what the World Health Organization deems safe to breathe. 

The concentration of PM2.5 -- the tiny air particles that pose the greatest health risks – reportedly reached 647 micrograms per cubic meter near Tiananmen Square on Christmas morning. 

This Tuesday, parts of Beijing again registered counts above 500. The WHO sets their limit of exposure at no more than 25 micrograms per cubic meter over a 24-hour period.

Experts warn that the situation will likely worsen in the weeks ahead.

"We're just getting into high season," said John Groopman, an environmental health expert at Johns Hopkins Bloomberg School of Public Health, as he prepped for a trip to China this week to research the issue. 

Cold weather, he explained, can trap polluted air near the surface of the earth. 

Meanwhile, more pollution is generally created during winter months due to increased heating, which is mostly supplied in China by burning coal.

The poster child for air pollution troubles, China also offers a cautionary tale for other parts of the world.

Pollution is currently soaring in parts of Iran and Italy, for example, where schools, vehicles, football matches and even pizza ovens have shut down in efforts to clean up the toxic air. 

Groopman suggests tha  India, whose rapidly growing population is even more dependent on coal than China, may be in the worst shape of all. 

A study released in February found that 660 million Indians lose an average of 3.2 years of life due to air pollution exposure.

Bad air from Asia can also travel overseas, contributing to the mercury and other pollution plaguing the U.S. West Coast.

Overall, according to the WHO, bad air causes the premature deaths of more than 7 million people every year. 

And the list of air pollution's effects is well-known and staggering: heart disease, lung disease, cognitive problems, obesity and even increased crime rates. 

"It's really quite obvious that no one should be breathing this," said Groopman.

Pollution Changes Out Brains

DID YOU KNOW?

• Male brains are more strongly affected by pollution than female brains
• Pollution exposure could cause memory and learning problems in people
• It causes 'rampant' inflammation throughout the brain

Early exposure to air pollution causes harmful changes in the brain seen in autism and schizophrenia, research has shown.

The findings in mice follow previous research linking traffic pollution and higher rates of autism in children.

As in humans, it was mostly male mice that were affected. 

Besides suffering physical damage to their brains, they performed poorly in tests of short-term memory, learning ability and impulses.

Exposure to air pollution causes harmful changes in the brain seen in autism and schizophrenia

In a series of experiments, scientists exposed mice to levels of air pollution typically found in medium-sized cities during the first two weeks after birth.

Mice examined 24 hours after their last exposure displayed evidence of ‘rampant’ inflammation throughout their brains.

Fluid-filled ventricle chambers on both sides of the brain were also enlarged to two or three times their normal size.

Lead researcher Professor Deborah Cory-Slechta, from the University of Rochester, U.S., said: ‘When we looked closely at the ventricles, we could see that the white matter that normally surrounds them hadn’t fully developed.

‘It appears that inflammation had damaged those brain cells and prevented that region of the brain from developing, and the ventricles simply expanded to fill the space.

‘Our findings add to the growing body of evidence that air pollution may play a role in autism, as well as in other neurodevelopmental disorders.’

Pollution has a more significant effect on the brains of boys than of girls - autism is also more common in boys.

The same defects were seen in other groups of mice 40 and 270 days after exposure, suggesting they were permanent.

Brains of all three groups of mice also had raised levels of the nerve message chemical glutamate. 

Again, this is seen in humans with autism and schizophrenia.

The research, published in the journal Environmental Health Perspectives, focused on ultra-fine carbon particles of the type produced by factories and motor vehicles.

Being so small, the particles can travel deep into the lungs and become absorbed into the bloodstream.

Last year, a study published in the journal JAMA Psychiatry showed that children who spend the first year of life in areas highly polluted by traffic are three times more likely to develop autism.