Tungsten: an Emerging Toxicant, Alone or in Combination.

PURPOSE OF REVIEW: Tungsten is an emerging environmental toxicant, yet our understanding of the potential risks of exposure on human health is still limited.

RECENT FINDINGS: In this review, we will discuss populations most at risk of exposure to high concentrations of tungsten. In addition, we will highlight what is known about the toxicity profile of tungsten compounds, based on epidemiological, in vitro, and in vivo studies, focusing on bone, immune, pulmonary, and cancer outcomes. Of note, emerging evidence indicates that tungsten can augment the effects of other stimulants, stressors, and toxicants. Of particular importance may be tungsten-cobalt mixtures that seem to be more toxic than either metal alone. This is important because it means that we cannot just evaluate the toxicity of tungsten in isolation. Finally, we still have limited information of how many of the in vitro and in vivo findings translate to human populations, so it will be important to conduct epidemiology studies in highly exposed populations to adequately address the potential risks of tungsten exposure on human health. Together, we discuss recent findings that support further investigation into the toxicities of tungsten alone and in combination with other metals.