A Review of the Effect of Outdoor Polycyclic Aromatic Hydrocarbons on Bladder Cancer

Context: Polycyclic aromatic hydrocarbons (PAHs) are pollutants that are among the most important risk factors for cancer, especially in individuals with underlying diseases. On the other hand, various types of cancers in the vital organs of the body, including the liver, lung, and bladder, and diseases related to the nervous system can be attributed to exposure to this polluting agent. Bladder cancer depends on numerous factors, such as inherited genetic predisposition and external exposure. Polycyclic aromatic hydrocarbons are by-products arising from the incomplete combustion of organic matter. They are found in all environments, such as hospitals, industries, and homes. Objectives: The purpose of this review study was to investigate the epidemiological literature on the side effects of PAHs on bladder cancer and the risk factors related to cancer. Methods: A total of 80 articles according to different databases, namely PubMed, Web of Science, Springer, Cochrane, and ScienceDirect, were retrieved. Then, 38 full-text articles were entered into the analysis process. Finally, 12 articles were selected for this study. Results: The literature review showed that PAH exposure occurs in daily life through exposure to tobacco smoke, consumption of charcoal-smoked meats, and inhalation of air pollutants. The concentration of PAHs is related to the risk of developing bladder cancer during the lifetime of PAHs. Bladder tumors are directly related to exposure to carcinogens. While the exposure to risk factors increases, the risk of developing cancer increases. Risk factors affecting bladder cancer include smoking and occupational and dietary factors. Conclusions: Polycyclic aromatic hydrocarbons are by-products of incomplete combustion of organic matter. They are found in all environments, such as hospitals, industries, and homes, and they can affect the urinary system, cause dysfunction, and eventually cause bladder cancer.