[ZenDers]

In California’s Los Angeles Basin, levels of some vehicle-related air pollutants have decreased by about 98 percent since the 1960s, even as area residents now burn three times as much gasoline and diesel fuel. Between 2002 and 2010 alone, the concentration of air pollutants called volatile organic compounds (VOCs) dropped by half, according to a new study by NOAA scientists and colleagues.

“The reason is simple: Cars are getting cleaner,” said Carsten Warneke, a NOAA-funded scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.

VOCs, primarily emitted from the tailpipes of vehicles, are a key ingredient in the formation of ground-level ozone which, at high levels, can harm people’s lungs and damage crops and other plants.

The magnitude of the drop in VOC levels was surprising, even to researchers who expected some kind of decrease resulting from California’s longtime efforts to control vehicle pollution.

“Even on the most polluted day during a research mission in 2010, we measured half the VOCs we had seen just eight years earlier,” Warneke said. “The difference was amazing.”

The study was published online today in the Journal of Geophysical Research-Atmospheres, a journal of the American Geophysical Union.


great news considering all the new oil discoveriesfinds

[blackjackiisre]

Well that's good news.

[Morageort]

Yes, great news.
It reminds me of the early years of the Thames being cleaned up ... it had not seemed possible when they began.

[Acrogeokickic]

VOCs are also released at service stations when you fill up the tank. As the tank is filled, all the gasses inside are expelled by the incoming petrol and released into the atmosphere..except in California where they've had pumps with filters on them for decades.

California has been at the forefront of vehicle pollution control and it's good to see it paying off.

[nickayary]

So, what you seem to be saying here, is that chemists have once again stepped in to save the world?



:-)












There might have also been some engineers involved.

[ceagstuntee]

> So, what you seem to be saying here, is that chemists have once again stepped in to save the world? ... There might have also been some engineers involved.

The engineering came about 100 years after the chemistry.

The key change was in new additives in the petrol. But which additive is used: potassium-, manganese-, sodium- or phosphorus-based additive?

Similar pollution declines have been seen in cities elsewhere. But not in cities in China for some reason.

[Acrogeokickic]

> .........
The key change was in new additives in the petrol. But which additive is used: potassium-, manganese-, sodium- or phosphorus-based additive?

Similar pollution declines have been seen in cities elsewhere. But not in cities in China for some reason.

I would have though that the use of catalytic converters was more significant.

[ZenDers]

I would have though that the use of catalytic converters was more significant.
Requirements for catalytic converters, use of reformulated fuels less prone to evaporate, and improved engine efficiency of new vehicles have all likely contributed to overall declines in vehicle-related pollution, including VOCs.


Another recent study led by CIRES and NOAA researchers and published online August 4 in Geophysical Research Letters, also an AGU journal, has shown that one VOC, ethanol, is increasing in the atmosphere, consistent with its increasing use in transportation fuels.