A polycyclic aromatic hydrocarbon (PAH) refers to a type of organic compound composed of multiple fused aromatic rings, typically containing two or more six-carbon rings. PAHs are formed through various natural and human activities, including volcanic eruptions, forest fires, and industrial processes like combustion of fossil fuels or organic matter. They are commonly found as byproducts of incomplete combustion and are often present in air, soil, water bodies, and sediments.
Due to their complex chemical structure, PAHs exhibit a high degree of stability and resistance to degradation. They can persist in the environment for long periods, posing potential risks to human and environmental health. PAHs are notorious environmental pollutants due to their carcinogenic, mutagenic, and potential endocrine-disrupting properties. Some common examples of PAHs include naphthalene, anthracene, phenanthrene, and benzo[a]pyrene.
Exposure to PAHs can occur through inhalation, ingestion, or dermal contact, with routes varying depending on the specific environmental context. Human activities such as tobacco smoking, living near industrial areas, or consuming charbroiled or smoked foods can significantly contribute to higher exposure levels.
Owing to their potential adverse effects on living organisms, PAHs are commonly monitored and regulated by environmental agencies. Efforts are made to mitigate their release into the environment, improve combustion processes, and remediate contaminated sites to minimize human and ecological exposure to these harmful compounds.
