Polycyclic aromatic hydrocarbons (PAHs) are a type of molecule formed from burned and unburned kinds of fossil fuels. Other sources of this chemical include cigarettes and charred or grilled foods. Within the past decade, the Centers for Disease Control and Prevention measured multiple different PAH metabolic byproducts in more than 2,500 participants over the age of six. They found evidence of PAHs in most participants, indicating the pervasive nature of PAHs in the United States population. PAHs have been linked to certain health conditions, and given the high burden of heart disease, it is essential to examine the impact of PAHs on heart health.
In December 2021, a systematic review examining this relationship was published. The search yielded 20 articles which mainly included time-series, cohort, and cross-sectional studies. The Newcastle-Ottawa scale and modified Newcastle-Ottawa scale were used to assess the quality of retrospective cohort and cross-sectional studies, respectively, all of which were high quality. Most of the included studies were performed in the United States; however, studies from other countries were included in the analysis.
This review indicated a significant positive association between PAH exposure and risk of cardiovascular diseases. Concerningly, studies demonstrated that in areas contaminated with PAHs, those with pre-existing cardiovascular risk factors such as older age, obesity, and diabetes are more adversely impacted. In the Chinese population, it was found that the presence of specific PAH metabolites in the urine was linked to a higher prevalence of atherosclerotic disease within ten years. In the United States, these chemicals are linked to hypertension, a leading cause of stroke. Although the underlying mechanisms through which PAH exposure can contribute to cardiovascular disease are elusive, emerging research suggests that PAHs can lead to inflammation and stress within the body.
Although certain limitations of this review exist, such as the inclusion of only studies written in English and retrospective studies, the body of evidence provides a compelling argument for the regulation and monitoring of PAHs in the environment both in developed and developing countries. This is particularly important in occupational settings and areas of high pollution. Environmental and public health authorities should also educate the public concerning the dangers of PAH exposure and how to avoid them.