Cadmium in tobacco smokers: a neglected link to lung disease?

Abstract

Cadmium in tobacco smoke may contribute to the development of pulmonary emphysema. However, there is poor understanding of the mechanisms behind the pathogenic role of cadmium in this and other smoking-related lung diseases. The traditional focus on the total body burden of cadmium, estimated through analysis of urine, may not fully reflect the local burden of cadmium, since it is inhaled by smokers. Thus, assessing the local accumulation of cadmium in the lungs appears more relevant, given that there is tissue-specific retention of cadmium.In this review, we outline the principal sources of cadmium exposure and the clinical effects of occupational exposure. In addition, we review evidence on local cadmium and its association with alterations in innate immunity in tobacco smokers. Moreover, we scrutinise the data on cadmium as a cause of lung disease in translational models.We conclude that cadmium may contribute to smoking-related lung diseases, possibly via an altered redox balance and by making macrophages dysfunctional. However, there is a need for new studies on local cadmium levels and their relation to pathology in long-term tobacco smokers, as well as for more indepth studies on cellular and molecular mechanisms, to elucidate the importance of cadmium in smokingrelated lung diseases.

Cadmium‐induced toxicity increases prolyl endopeptidase (PREP) expression in the rat testis

“…Tobacco smoking is a major source of Cd intake, a cigarette contains 5 mg of this metal, which could lead to significantly 4–5 times higher levels of Cd in smokers’ blood than that of non‐smokers (Djuric et al, 2015; Takiguchi & Yoshihara, 2006). Generally, the Cd poisoning is the result of a chronic exposure, which is mainly reflected to bone (Järup, Alfvén, Persson, Toss and Elinder, 1998; Knani, Bartolini, et al, 2019; Knani, Venditti, et al, 2019; Xie & Sheng, 2017), kidney (Johri, Jacquillet, & Unwin, 2010; Satarug, 2018), gastrointestinal tract (Tinkov et al, 2018), lung (Ganguly, Levänen, Palmberg, Åkesson, & Lindén, 2018), and testis pathologies, whereas the latest one is the major target organ of Cd toxicity, due to its high sensitivity (Siu, Mruk, Porto, & Cheng, 2009).…”

Cigarette-related cadmium and environmental pollution exposure are reflected in airway ultrafine particle content

“…Local toxicity of cadmium in the lungs increases smokers' susceptibility to develop lung diseases, but there are not enough data regarding local deposition of cadmium in lungs [41]. Therefore, measurements of cadmium levels in lung compartments is crucial for a better understanding of the role of cadmium in smoking-related lung diseases.…”

Environmental Exposures during Puberty: Window of Breast Cancer Risk and Epigenetic Damage

“…Heavy metal contamination come from a variety of sources including both point sources (mining) and nonpoint sources (lead pipes). The main causes of water contamination come from metal refineries, cigarette smoke, improper disposal of waste (electronics/batteries), industrial discharge, and leeching from processing sites [44,45].…”