A recent study published inEnvironmental Health evaluates the association between air pollution such as ozone and particulate matter and cardiovascular disease.
Air pollution is an independent risk factor for cardiovascular disease. Based on epidemiological studies, the strongest association occurs between particulate matter (the sum of tiny particles and liquid droplets suspended in the air) and cardiovascular morbidity and mortality. In addition to particulate matter, research has demonstrated that there is also an association between ozone, a toxic gas, and cardiovascular effects like coronary artery disease, cardiac arrests, and ischemic strokes. Human-based studies are required to increase our understanding of the relationship between ozone and cardiovascular disease events.
This study, published in the Environmental Health journal, has evaluated the associations between ozone and changes across biological pathways associated with cardiovascular disease.
This cohort study was conducted at Duke University in the United States. The participants of the study included people from the Duke University Medical Center Catheterization Genetics (CATHGEN) cohort of nearly 10,000 individuals. Suitable potential participants were sent a letter for the invitation. Among the respondents, 15 met the criteria for inclusion in the study. Among the 15 participants, 13 with coronary artery disease were assessed for systemic inflammation markers, heart rate, lipid profile, blood pressure, and vascular function. Ozone and particulate matter were being assessed on a daily basis.
The results showed that the elasticity of large arteries, a determinant of susceptibility to various cardiovascular diseases, is associated with increased ozone concentrations. There was also a decrease in the diameter of the brachial artery with increasing ozone concentrations. Ozone was also accompanied by an increase in concentrates of the tissue plasminogen activator and plasminogen activator inhibitor, which are two substances that are involved in clot formation and degradation. High ozone concentration was also associated with increased neutrophil and monocyte count as well as increased IL-6, IL-8, TNF-α, CRP concentration. These substances are markers and mediators of inflammation.
Several pathways to cardiovascular disease were altered with ozone exposure. The important results indicate that there may an association between exposure to ozone and cardiovascular disease. Based on the author’s conclusion, ozone exposure was associated with increased cardiovascular morbidity and mortality after excluding the impact of particulate matter. Notably, these effects were seen as ozone concentrations that were even below the Environmental Protection Agency National Air Quality Standards.
Written by Nima Makhdami, M.D.
Reference: Mirowsky, J. E., Carraway, M. S., Dhingra, R., Tong, H., Neas, L., Diaz-Sanchez, D., … & Dowdy, Z. E. (2017). Ozone exposure is associated with acute changes in inflammation, fibrinolysis, and endothelial cell function in coronary artery disease patients. Environmental Health.