mexico city: 40% of cars ordered off the road...for months

[cheka.]

http://www.theweathernetwork.com/us/news/articles/climate-and-environment/mexico-city-orders-40-of-cars-off-roads-amidst-smog-crisis/67453/

Friday, May 6, 2016, 2:54 - Mexico City's government ordered traffic restrictions on Thursday and recommended people stay indoors due to serious air pollution, as a smog alert in the sprawling capital heads into its fifth day.

According to officials, 40 percent of vehicles will be ordered off the road. A start date for the vehicle restrictions has not yet been officially announced, but restrictions are expected to remain in place until at least until June 30, according to officials. Factories around the capital have also been told to reduce emissions.

But cyclist Luis Humberto Silva told Reuters the measures have not been effective.

"I think they can do other additional things rather than just taking two million cars (off the roads) because rather than (pollution) decreasing it has increased, from what I have seen. I think they (authorities) should consult personally with people to tell them exactly what is happening," he said.

While conditions persisted, residents were better off inside between 1 p.m. and 7 p.m., should refrain from vigourous exercise in the open and curb sporting activities to avoid respiratory problems, the capital's government has reported.

"I try to run in the mornings when the quality of air is a little better. Going out in the afternoons is no good because being (outside) can cause a lot of damage, additionally because of the sun and temperature," said jogger Martin Gutierrez.

The recent spate of smog warnings followed a period of relative air quality in the metropolis. The warning had not previously been seen since September 2002.

"You have a fleet of vehicles of more than four million vehicles which are circulating at the same time. This saturated our roads and throwing off the capacity equilibrium of pollution in this already fragile region. Our main focus of attention for reducing emissions is vehicles," said Executive Direction of the Metropolitan Environment Commission, Martin Gutierrez.

The government said the alert stemmed from an "extraordinary increase" in ozone concentration due to the presence of a high pressure system and intense solar radiation around greater Mexico City, which is home to more than 20 million people.

"Unfortunately, we're relying on the weather. This (restriction) is due to the stress of the heat and pollution, which have reduced due reductions in vehicles circulating. It's falling but there is a previous accumulation. It's important that the weather changes," added Gutierrez.

Ozone, which is a key ingredient of smog, is a form of oxygen created by the reaction of sunlight with air containing other pollutants such as hydrocarbons and nitrogen oxide.

It can cause breathing difficulties and worsen heart disease. Children and the elderly are especially at risk.

[Ponce]

I went to Mexico city back in 79 to see my dad who was in with a delegation from Cuba..... the smog and the smell was horrible, and that was in 79...... only God knows what it is like at this time.

V

[Terry853]

When last I checked Mexico had more people crammed into one city built in a swamp than the population of Canada, the second largest by size country in the world.

[Serpo]

How dangerous is rubber dust?

http://www.abc.net.au/reslib/201207/r979041_10691794.jpg (http://www.abc.net.au/reslib/201207/r979041_10691812.jpg)Black mark: Each time a tyre rotates, it loses a layer of rubber about a billionth of a metre thick. (iStockphoto: rcyoung)


Related Stories



Audio: How dangerous is rubber dust? (Science Online Audio) (http://mpegmedia.abc.net.au/science/podcast/gmis/gmis20120731.mp3)



In our modern cities, roads make up about one-fifth of the urban land area, and about half of the impervious surfaces. On these roads we have driven our cars and trucks with inflatable rubber tyres for over a century. These rubber tyres wear, and have to be regularly replaced.
Sometimes the rubber comes off in a dramatic cloud of smoke when the car skids on the road. Sometimes the road surface is sharp and slices fragments out of the rubber. But most of the time, in the course of normal rotation without skidding or cutting, the rubber is compressed and then expands. As it compresses and expands, tiny cracks develop and spread in the tread — and tiny particles of rubber flake off.
How much rubber dust is there, where does it go, and is it harmful?
Each time a tyre rotates, it loses a layer of rubber about a billionth of a metre thick. If you do some numbers, this works out to about four million million million carbon atoms lost with each rotation.
A busy road with 25,000 vehicles travelling on it each day will generate around nine kilograms of tyre dust per kilometre. In the USA, about 600,000 tonnes of tyre dust comes off vehicles every year.
In the Australian outback, traces of lead from car exhausts have been found up to 50 kilometres away from the nearest road. So some of the tyre dust can travel that far — but of course, most of it will settle around the road.
Some of the tyre dust gets mashed into the road. Most of it gets blown off away from the road by the air turbulence of the vehicles. And rain easily washes the rubber dust off the road into the nearest waterways where it ends up as sediment on the bottom of creeks, ponds and wetlands.
Tyre dust contains two main classes of chemicals — organic and inorganic.
These organic chemicals are especially toxic to aquatic creatures (such as fish and frogs), and depending on the levels, can cause mutations, or even death. In test tube laboratory experiments, they damage human DNA. Latex (a component of rubber dust) has been implicated in latex allergies and asthma.
Some of the inorganic chemicals in tyre dust are heavy metals (such as lead and zinc).
But there's another dark side to rubber dust — particles. The organic and inorganic chemicals are carried as, or on, particles. In general, the smaller the particles, the more deeply they can penetrate into your lungs. PM10 stands for particulate matter that is smaller than 10 microns in size. (A micron is a millionth of a metre. A human hair is about 70 microns thick). PM2.5 particles are smaller than 2.5 microns, and are even more dangerous.
On average, about 80 per cent of all PM10 in cities comes from road transport. Tyre and brake wear causes about three to seven per cent of this component. Each year in the UK, PM10s of all types are blamed for an extra 10,000 deaths, due to heart and lung disease.
In Europe each year, the normal wearing of tyres releases some 40,000 tonnes of PAHs (polycyclic aromatic hydrocarbons), mostly as PM10. PAHs are a component of the heavy oils used to make tyres. They accumulate in living tissue, and have been implicated in various cancers.
California is notorious for its heavy smog pollution — which can vary from day to day. One study showed very strong links between PM2.5 particles, and the daily death rate in six Californian counties. When the PM2.5 count was high, so was the death rate.
Back in 1922, T S Elliot wrote his poem The Waste Land. In it appear these words: "I will show you fear in a handful of dust." We don't need to be terrified of rubber dust just yet. But we do need to know how dangerous it is. Even today, after over a century of using rubber tyres, we are not still not sure of the exact health hazards of the rubber from the tread of tyres.
Luckily, modern tyres last much longer than they used to, so there's less tyre dust ending up in the environment. You still need a spare tyre, but it's better in your boot than around your waist — or even worse, in your lungs.



http://www.abc.net.au/science/articles/2012/07/31/3554997.htm






(http://www.abc.net.au/science/articles/2012/07/31/3554997.htm)Nevertheless, automobile tyres as a source of deterioration products till now remain out of sight of the experts engaged in technical rationing. For a long time was considered, that tyre protector deterioration product particle sizes are large enough and do not pose a health hazard. However, research of the American doctors [1], who noticed a higher sensibility to allergic and oncology diseases of inhabitants of the houses located near to motorways in cities, had allowed to assume, that at natural wear of automobile tyres significant amount of aerosol is emitted to the atmosphere. After thorough research of the air at highway with moderate traffic, the researchers found between 3,800 and 6,900 tyre particles per cubic meter of air while more the 58% of them are under 10 microns in size and therefore are able to penetrate into human lungs causing bronchial asthma, allergic reactions, as a result of skin and mucosa contact – rhinitis, conjunctivitis and urticaria. Such tyre particles almost cannot be excreted from the body.
According to the research carried out in Moscow [2] the core pollutant of the city air (up to 60% of hazardous matter) is the rubber of automobile tyre used up in a small dust.

https://www.unece.org/fileadmin/DAM/trans/doc/2013/wp29grpe/GRPE-65-20e.pdf

[Half Sense]

Not just cars, but tens of millions of open cook fires each day in Mexico City.