Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds with two or more fused aromatic rings. They are lipophilic, have low water solubility, and are commonly found in the environment due to incomplete combustion of organic materials. PAHs are widespread environmental contaminants, originating from sources such as fossil fuel burning, motor vehicles, waste incineration, and industrial processes. They are of concern due to their potential carcinogenic and mutagenic properties. Eight PAHs, including benzo(a)pyrene, are considered possible carcinogens. The US Environmental Protection Agency (EPA) has identified 16 PAHs as priority pollutants. PAHs can be found in various environmental samples, including air, soil, water, and food. They can be adsorbed onto particles and undergo photodecomposition when exposed to ultraviolet light. PAHs can also be degraded by microorganisms in soil. In the atmosphere, PAHs react with pollutants such as ozone, nitrogen oxides, and sulfur dioxide, forming various derivatives. PAHs are a significant health concern, particularly in urban areas where they are more concentrated due to increased vehicular traffic and pollution. PAHs are found in plants, where they can be absorbed through the cuticle or stomata. The concentration of PAHs in plant tissues varies depending on factors such as leaf surface area, cuticular waxes, and atmospheric conditions. Plants can act as bioindicators of PAH pollution, with certain species accumulating higher concentrations of PAHs. PAHs can also enter plant tissues through contaminated soil and translocate to the shoots. In food, PAHs can be ingested through grilled or charred meats, contaminated cereals, and vegetables. PAHs can be transferred from animals to humans through the food chain. The concentration of PAHs in food varies depending on the source and preparation method. PAHs can also be found in milk and other dairy products, with concentrations influenced by the diet of the animal. In water, PAHs enter surface waters through atmospheric fallout, urban runoff, and industrial effluents. PAHs can be found in both dissolved and particulate phases in water. The concentration of PAHs in water varies depending on the source and environmental conditions. PAHs can also be found in groundwater, where they are adsorbed to organic soil particles. In air, PAHs are primarily found in particulate matter, with higher concentrations in urban areas due to increased vehicular traffic and pollution. PAHs can be inhaled and pose health risks, particularly in areas with high levels of pollution. PAHs can also be found in indoor air, where they can be inhaled from outdoor air or from indoor sources such as cooking and gas appliances. The review discusses the use of bioaccumulation and biomarker responses in assessing the risks and hazards of PAH concentrationsPolycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds with two or more fused aromatic rings. They are lipophilic, have low water solubility, and are commonly found in the environment due to incomplete combustion of organic materials. PAHs are widespread environmental contaminants, originating from sources such as fossil fuel burning, motor vehicles, waste incineration, and industrial processes. They are of concern due to their potential carcinogenic and mutagenic properties. Eight PAHs, including benzo(a)pyrene, are considered possible carcinogens. The US Environmental Protection Agency (EPA) has identified 16 PAHs as priority pollutants. PAHs can be found in various environmental samples, including air, soil, water, and food. They can be adsorbed onto particles and undergo photodecomposition when exposed to ultraviolet light. PAHs can also be degraded by microorganisms in soil. In the atmosphere, PAHs react with pollutants such as ozone, nitrogen oxides, and sulfur dioxide, forming various derivatives. PAHs are a significant health concern, particularly in urban areas where they are more concentrated due to increased vehicular traffic and pollution. PAHs are found in plants, where they can be absorbed through the cuticle or stomata. The concentration of PAHs in plant tissues varies depending on factors such as leaf surface area, cuticular waxes, and atmospheric conditions. Plants can act as bioindicators of PAH pollution, with certain species accumulating higher concentrations of PAHs. PAHs can also enter plant tissues through contaminated soil and translocate to the shoots. In food, PAHs can be ingested through grilled or charred meats, contaminated cereals, and vegetables. PAHs can be transferred from animals to humans through the food chain. The concentration of PAHs in food varies depending on the source and preparation method. PAHs can also be found in milk and other dairy products, with concentrations influenced by the diet of the animal. In water, PAHs enter surface waters through atmospheric fallout, urban runoff, and industrial effluents. PAHs can be found in both dissolved and particulate phases in water. The concentration of PAHs in water varies depending on the source and environmental conditions. PAHs can also be found in groundwater, where they are adsorbed to organic soil particles. In air, PAHs are primarily found in particulate matter, with higher concentrations in urban areas due to increased vehicular traffic and pollution. PAHs can be inhaled and pose health risks, particularly in areas with high levels of pollution. PAHs can also be found in indoor air, where they can be inhaled from outdoor air or from indoor sources such as cooking and gas appliances. The review discusses the use of bioaccumulation and biomarker responses in assessing the risks and hazards of PAH concentrations