Lung Cancer and Exposure to Metals: The Epidemiological Evidence

Abstract

Exposure to metallic compounds is ubiquitous, with its widespread use in industry and its presence, mostly in trace amounts, in the environment. This paper reviews the epidemiologic evidence of the relation between lung cancer and exposure to metallic compounds by building on and updating the corresponding International Agency for Research on Cancer (IARC) assessments. Given that most of the well-identified human populations with given metal exposure are in occupational settings, this review is mostly based on results in occupational epidemiology. The epidemiological evidence is shortly reviewed for accepted carcinogens: chromium, nickel, beryllium, cadmium, arsenic, and silicon, highlighting what is still unclear. We then review in more detail metals for which the evidence is less clear: lead, titanium, iron, and cobalt. There is scarce evidence for the human carcinogenicity of titanium. Exposure to titanium dioxide is associated with lung cancer excesses in one large study, but this excess may be due to confounders. The evidence for lead is contradictory. The lung cancer risk is presented as a function of a post hoc exposure ranking but no dose-response relationship is found. A weak but consistent lung cancer excess in many populations exposed to iron oxides but it is not possible to state on causality. Finally the evidence in the hard metal industry is presented, which suggests a possible carcinogenic effect of cobalt in presence of tungsten carbide. A short discussion presents the limitations of epidemiology in assessing the carcinogenicity of metals.

Trace Metals Concentrations at the Atmosphere Particulate Matters in the Southeast Asian Mega City (Dhaka, Bangladesh)

“…Among the inorganic compounds, most important ones are the trace metals, which are emitted by various natural and anthropogenic sources such as crustal materials, road dust, construction activities, motor vehicles, coal and oil combustion, incineration and other industrial activities [3]- [7]. Health impacts associated with particulate matters are linked to respiratory, cardiovascular problems, premature mortality, lung cancer, heart diseases and also damage to other organs [8]- [11]. Several studies have indicated that different transition metals may act as possible mediators of particle induced injury and inflammation [12] [13].…”

How a Steel Plant Affects Air Quality of a Nearby Urban Area: A Study on Metals and PAH Concentrations

“…The chemical composition of PM and particle size distributions are the most significant factors affecting air quality. In particular, the exposure to finer particles can cause short and long-term effects such as increased respiratory symptoms, decreased lung function, alterations in tissue and structure lung, in respiratory tract and premature death (Prieditis et al, 2002, Damek-Poprawa, 2003, Wahab et al, 2004, Huang and Ghio, 2006, Ahumada et al, 2007, Huang et al, 2007, Magas et al, 2007, Wild et al, 2009, Liuzzi et al, 2011. Moreover, near industrial areas, where elements and Polycyclic Aromatic Hydrocarbons (PAHs) are strongly associated with fine particles, increased toxicity and PM carcinogenicity have been determined (Bruno et al, 2002;Caselli et al, 2003;Pozzoli et al, 2004;Vione et al, 2004;Dvorskà et al, 2011;Castro-Jiménez et al, 2012;Tobiszewski and Namiesnik, 2012).…”

Chromatin Memory in the Development of Human Cancers

“…Occupational exposure to particulate matter and its metal components including nickel compounds through inhalation has been associated with lung and nasal cancers [141][142][143], while exposure to arsenic has been associated with skin, lung, bladder, kidney, and liver cancers [144,145]. Ex vivo exposure of Ni to peripheral blood mononuclear cells (PBMCs) from healthy subjects induced an increase in global levels of H3K4me3 and H3K9me2, which might well lead to a total of 1381 gene expression increase with a greater than 2-fold difference in expression in all treatments as compared to untreated control [145].…”