海角大神

New report finds cleaner air for many, but not all

The American Lung Association, which tracks air quality in the United States, says the Clean Air Act is working.

More Americans have been breathing easy in recent years.

On Wednesday, the American Lung Association (ALA) released its annual 鈥溾�� report, which tracks air quality for the years 2013-2015, both nationally and for specific metrics, like cities and types of pollution.

While some areas showed continued improvement and others deterioration, overall the report found that 鈥渢he number of people exposed to unhealthy levels of air pollution dropped to more than 125 million people," down almost 25 percent from 166 million in the years covered in the previous report (2012 鈥� 2014).

The report credits this progress to the Clean Air Act, one of the US environmental movement鈥檚 landmark achievements passed in 1970, and the scientists who study this issue agree. But in some parts of the country 鈥� especially California 鈥� environmental advocates see a need for smart policy decisions that will continue cleaning the air.

鈥淭his [report] is just further evidence that our efforts to clean up the air are working, but that we have to push further to help improve the air ... for everybody in the country,鈥� Chris Cappa, a professor in the department of civil and environmental engineering at聽University of California鈥揇avis, tells 海角大神 in a phone interview.

Air pollution in such places as Beijing and New Delhi has made headlines in recent years, but the mid-20th century saw many American cities wrapped . In October 1948, the air over Denora, Penn., got so thick with smog from its steel and wire factory that the industrial town鈥檚 fire department handed out oxygen tanks to ailing residents. The pollution killed 20 people and left half of the town's 14,000 residents recovering in hospitals or at home.

A series of policies meant to prevent this disaster from happening again culminated in 1970 with the Clean Air Act鈥檚 passage. , the US Environmental Protection Agency (EPA) must set science-based air quality standards for common types of air quality pollutants, and requires states to set enforceable limits on meeting those standards. Other components of the act cover interstate pollution and mobile emitters, such as car tailpipes.

鈥淲hile there are other factors鈥� behind the drop, 鈥渢he Clean Air Act has probably been the most important component,鈥� explains Cort Anastasio, professor in the air, land, and water resources department聽at UC-Davis, in an email to the Monitor.

鈥淓PA regulations,鈥� he continues, 鈥渨hile regularly derided by some in (and out) of politics, are making our air cleaner and provide benefits (in the form of increased human health) that far outweigh their costs.鈥�

Contrary to concerns that these regulations would stifle businesses, that just one provision of the act 鈥� 1990 amendments that target acid rain 鈥� will yield an economic benefit of $2 trillion by 2020,聽at an enforcement cost of $65 billion. Already, the ALA's report notes that America's gross domestic product has grown by 246 percent since the Act was passed 鈥� even as emissions of the six main pollutants it targets have fallen by 71 percent.聽

Despite these gains, not everyone is seeing cleaner skies. The ALA found that 18 million Americans 鈥渓ive in 12 counties with unhealthful levels of all three [pollutants tracked in the study]: ozone and short-term and year-round particle pollution.鈥� And even as ozone and year-round particle pollution have dropped, it observed 鈥渁n unrelenting increase in dangerous spikes in particle pollution.鈥�

For both short-term 鈥渟pikes鈥� and a year-round presence of dust, smoke, and soot particles, , and some, like Bakersfield in the Central Valley, .

The Golden State鈥檚 hill-and-valley topography helps create 鈥渢hermal inversions,鈥� layers of warm air that trap smog in low-lying areas. While cities like Los Angeles have been grappling with this problem for decades, Professor Anastasio聽says that recent environmental changes may have driven the latest increase.

鈥淢y guess is that the California drought is partially responsible for making fine particle ... pollution worse since 2010,鈥� he writes in an email. 鈥淲inter rains clean the air of particles, but we had little precipitation for the past five years, until this year.鈥�

Professor Cappa, his colleague at UC-Davis鈥檚 Air Quality Research Center, adds that the drought has brought an increase of wildfires. 鈥淲e've had a lot of pretty bad fire seasons lately, which can really lead to poor air quality,鈥� he says.

Cappa cautions against making too much of the recent increase. 鈥淲e want to pay attention to those [spikes],鈥� he explains, 鈥渂ut we don't necessarily want to overly worry right away, because that ... probably is linked to short-term changes in meteorology and climate in the area.鈥�

Both droughts and wildfires, he points out, are linked to climate change, meaning that curbing them could require stemming聽CO2 emissions. But at the same time, environmental advocate Nayamin Martinez also sees a need for stronger regulations at the local level.

Ms. Martinez serves as director of the Central California Environmental Justice Network (CCEJN); in her group鈥檚 view, the San Joaquin Valley Air Pollution Control District, which oversees emissions-reduction plans in Bakersfield, Fresno, and some of the other most-polluted cities, 鈥渃ould be coming up with regulations that are more stringent that could protect our air.鈥�

In a phone interview with the Monitor, Martinez points to one recent success in this effort: Advocacy from CCEJN and other environmental groups to reject San Joaquin鈥檚 plan to reduce particulate pollution, requiring it to come up with a more aggressive one.

In the nation's remaining pollution pockets, the ALA鈥檚 research bolsters the case for improvements like these.

When Martinez spoke with the Monitor on Wednesday afternoon, the local ALA chapter had already briefed her on the latest report. 鈥淗aving this type of national organization coming out with this information really backs up our argument,鈥� she says. 聽