Emerging biomarkers of pulmonary injury and their potential application for biomonitoring of nanomaterial workers

A limited number of experimental animal studies suggest that inhalation of engineered nanomaterials may have the capacity to cause chronic lung injury associated with chronic inflammation, granulomas, and pulmonary fibrosis. Common methods of conducting workplace medical surveillance for pulmonary disease, notably chest radiographs and spirometry, may have limited sensitivity and specificity for detecting the potential chronic effects of inhaled nanoparticulates, particularly in the early stages of the disease process when secondary prevention is most possible. Recent clinical and epidemiological research has identified new biomarkers of lung injury that may have potential utility in the biomonitoring of pulmonary injury. These include serum biomarkers such as KL-6, neopterin, CC-16, or alveolar surfactant proteins; chemokines and cytokines such as TNF-alpha or 8-isoprostane in exhaled breath condensate; exercise oximetry, and high-resolution computerized tomography. Because application of some of these biomarkers in various research settings has shown promise, their introduction into longitudinal epidemiological research studies in the nanotechnology industry merits consideration.