## 1 Introduction  
Polycyclic aromatic hydrocarbons (PAHs) cause significant environmental and health risks due to their persistence, bioaccumulation, and potential mutagenic and carcinogenic effects [1; 2]. Children are more vulnerable to PAH exposure through ingestion of contaminated food or inhalation of smoke from burning organic materials [3]. In adults, chronic exposure to PAHs, often through occupational settings or environmental pollution, has been associated with increased risks of lung cancer, skin, and cardiovascular disorders [4; 5]. Agricultural soils are considered as one of the main sinks of PAH contamination [6]. PAHs in agricultural soils primarily originate from atmospheric deposition, industrial activities, agricultural machineries, vehicle exhaust, biomass burning, brick kilns, and smoking [7; 8; 9; 10]. Additionally, pesticides and herbicides can introduce PAHs as impurities or byproducts of chemical synthesis. Organic amendments such as manure, compost, and sewage sludge, especially if derived from contaminated sources, also contribute to PAH levels [11; 12]. Irrigation with contaminated water can further exacerbate soil contamination. Proximity to industrial areas can lead to soil pollution through runoff, spillage, and atmospheric emissions. Historical land uses, including industrial sites and waste disposal areas, can leave residual PAHs [13]. Moreover, both natural and anthropogenic fires, such as forest fires and agricultural burning, release PAHs that can be deposited onto agricultural soils [14]. Polycyclic aromatic hydrocarbons (PAHs) enter plant parts primarily through two main pathways: root uptake and atmospheric deposition [15]. When present in the soil, PAHs can be absorbed by plant roots along with water and nutrients [16]. These compounds can then be translocated through the plant's vascular system to stems, leaves, and other tissues [17]. Additionally, once PAHs is deposited on the surface of plant parts, PAHs can penetrate the plant cuticle and enter internal tissues. The extent of PAH uptake and translocation within the plant depends on factors such as the specific PAHs involved, the plant species, environmental conditions, and the presence of soil microorganisms that may degrade PAHs [18; 19]. Studies have shown that up to 10% of certain PAHs can be found in the edible parts of plants [20]. However, the actual percentage can be influenced by factors such as the soil composition, PAH concentration in the environment, and the specific metabolic processes of the plant. The effect of soil depth on polycyclic aromatic hydrocarbon (PAH) concentration can vary based on factors such as deposition sources, mobility, and interactions with soil constituents. Typically, PAHs are more concentrated in surface soils due to atmospheric deposition and inputs from organic matter. However, their distribution in deeper soil layers can also occur depending on their mobility, rhizosphere activities, and the soil's physical and chemical properties [21; 22]. The vertical distribution of PAHs in soils provides insights into their sources, transformation processes, and interactions with soil components, highlighting the importance of considering soil depth when assessing PAH contamination risks. PAH concentrations can also vary widely across agricultural soils depending on land-use categories. This variation is influenced by factors such as land topography, agricultural practices, development activities, socioeconomic conditions, and the distinction between rural and urban areas. Bangladesh is considered one of the major hubs for pollutants, particularly PAHs, due to their numerous sources in agricultural soils [23; 24]. To develop a comprehensive understanding of PAH contamination patterns in Bangladesh agricultural soils, five land-use categories were identified. However, to the best of our knowledge, no comprehensive study has been conducted to systematically examine PAH levels in soils across different land use types and soil depths in Bangladesh.