Human biomonitoring (HBM) is a reliable methodology for assessing the exposure of populations or specific groups to multiple xenobiotics whether originating from natural sources or anthropogenic activities [1], [2], [3], [4]. HBM plays a pivotal role in health risk assessment and reference range establishment [5], [6]. Among the numerous substances, non-essential trace metals have garnered important attention in HBM research through epidemiological, clinical, and other studies [7], [8].

Different clinical samples were analyzed in the HBM studies. The primary focus has been on body fluids (such as serum, plasma, or urine) and keratin-based tissues (like hair and nails) [9]. This preference is motivated by their ease of access, minimally intrusive collection methods, and simpler composition compared to more complex solid tissues (e.g., bone, placenta, thyroid) [10], [11]. Body fluids are particularly adept at revealing short-term exposure patterns, providing insights into acute exposure dynamics [12]. However, the growing interest in HBM of trace elements in solid tissues arises from their ability to unveil long-term exposure trends, offering a comprehensive understanding of the interplay between toxic and essential trace elements [13], [14].

Lung tissue is attractive for toxicological research due to the complex interactions between trace elements facilitated by direct contact, abundant vascularization, and effective metal accumulation, but is rarely used for HBM due to invasive sampling procedures [15], [16]. The World Health Organization (WHO) recognizes several trace elements, including chromium (Cr), nickel (Ni), arsenic (As), and cadmium (Cd), as potential contributors to malignant lung transformation [17], while some other studies also found the influence of copper (Cu), iron (Fe), and cobalt (Co) [18], [19]. However, a quantitative foundation to support or refute epidemiological claims concerning the roles of these trace elements in neoplastic lung transformation remains elusive [20]. Consequently, establishing baseline levels of trace elements in healthy lung tissues devoid of pathological alterations—benign, malignant, or otherwise—is an important step in establishing the role of trace elements in lung oncogenesis [21]. Lung tissues can be acquired surgically or via bronchoscopy, with the latter approach providing limited sample mass, occasionally necessitating surgical collection [8]. However, the data on the levels of trace elements in healthy lungs are scarce, and not many studies focused on that topic [19], [22], [23], [24], [25], [26].

Given these challenges, this study aimed to determine the levels of essential trace elements [Cr, manganese (Mn), Fe, Co, Cu, zinc (Zn), and selenium (Se)], alongside toxic trace elements [Ni, As, strontium (Sr), Cd, and lead (Pb)], in lung tissues that had a normal (non-pathological) appearance on the histopathological microscopic examination, acquired through surgical means from patients with non-specific, non-malignant, non-infiltrative, and non-infective diseases. Additionally, we aimed to identify variations in the tissue trace element concentrations based on sex, age, and smoking habits, as well as possible correlations between concentrations of different trace elements within the healthy lung tissues.