"Asthma rates are on the rise in California, but the condition disproportionately affects low-income children and adults, according to a study from the UCLA Center for Health Policy Research.
With 4.9 million Californians suffering from the respiratory condition, researchers felt an urgent need to better understand the contributors to the asthma disparity. So they looked at data from the 2007 California Health Interview Survey to determine whether and how differences in income were associated with asthma diagnosis and treatment. (More on Time.com: Study: The Complicated Link Between Wealth and Obesity)
Throughout the state, rates of asthma had increased 13% overall between 2001 and 2007. The highest rates of asthma were found in lower-income inland areas, such as Fresno, where 12.9% of residents reported the respiratory disorder, and where the bottom-of-the-basin location means poorer air quality. Meanwhile, in wealthy, coastal, breezy San Francisco, asthma affected only 6% of residents — the lowest rate in the state.
Researchers also found that rates of secondhand smoke exposure — a known trigger for asthma — were three times higher among poor sufferers of the disease than in wealthy ones.