KINGSVILLE, Texas, July 27 (UPI) -- Exposure to ground level ozone -- a major component of smog -- increases the activity of a substance that triggers heart cell death, U.S. researchers say.
Rajat Sethi of Texas A&M Health Science Center Irma Lerma Rangel College of Pharmacy in Kingsville, Texas, and colleagues tested four groups of 10 rats living in clear plastic-glass boxes where they were exposed 8 hours daily for either 28 or 56 consecutive days to either ozone or clean, filtered air.
"Our study looked for direct evidence of the role of ozone alone in cardiac dysfunction by creating a controlled environment," Sethi said in a statement.
The researchers find the hearts of the ozone-exposed rats had increased levels of tumor necrosis factor-alpha -- an indication of inflammation linked to a drop in heart protective protein -- Caveolin 1 -- compared with hearts of the control rats.
This protective protein, explains Sethi, seems to protect the heart by binding to a chemical that signals cell death.
Researchers have long reported that deaths from lung diseases, heart attacks and strokes are significantly higher on days with high air pollution levels.
The findings were reported at American Heart Association's Basic Cardiovascular Sciences Scientific Sessions held at Rancho Mirage, Calif.