Southern Californians have some of the highest exposure to fine particulate matter and as a result are among those at highest risk of death due to air pollution, according to EPA research published in the journal Risk Analysis. The agency did say that overall levels of fine particles and ozone have declined, but obviously not enough to adequately lessen the dangers. From California Watch:
The study examined air pollution exposure based on 2005 air quality levels and projected there could be between 130,000 and 360,000 premature deaths among adults in coming years. The 2005 data was the best available for analyzing fine particulates and ozone, the EPA said. Among vulnerable populations like children, the EPA also estimates that fine particulate matter and ozone results in millions of cases of respiratory symptoms, asthma and school absences, as well as hundreds of thousands of cases of acute bronchitis and emergency room visits.
Other reports just released also found that people exposed to higher levels of air pollution have greater health risks. From the NYT:
One nationwide study that followed nearly 20,000 women over a decade found that breathing in levels of polluted air like those commonly found in most parts of the country greatly accelerates declines in measures of memory and attention span. Another study in Boston found that on days when concentrations of traffic pollutants went up, so did the risk of stroke. The odds climbed by more than 30 percent even on days classified by the federal air quality index as "moderate" pollution days, which is intended to correspond to a minimal danger to health.
Studying the links between pollution and health is difficult, since so many factors are involved and it is difficult to establish a direct cause-and-effect relationship. But a link between pollutants in the air and declines in cardiovascular health has been suspected since at least the 1990s, when epidemiological research suggested that breathing in tainted air drives up rates of heart disease. The possible short-term effects of pollution remained particularly unclear, with some studies showing no immediate short-term risk. And little was known about the impact of inhaling emissions and air particles on brain function and dementia.
As you might guess, the reports are being challenged by industry groups that basically say there's not enough evidence to prove cause and effect. To some extent, they have a point: When someone dies of a heart attack, it's impossible to know how much of that was due to pollution and how much was a function of being overweight and sedentary. Is there some sort of connection between dirty air and poor health? Probably. Is there a connection between dirty air and death? Lots of deaths? Here's where the competing spreadsheets take over.