Biomarkers of Exposure to Metal Dust in Exhaled Breath Condensate: Methodology Optimization

Abstract

In occupational assessments where workers are exposed to metal dust, the liquid condensate of exhaled breath (EBC) may provide unique indication of pulmonary exposure. The main goal of this study was to demonstrate the quality of EBC to biological monitoring of human exposure. A pilot study was performed in a group of metal dust-exposed workers and a group of nonexposed individuals working in offices. Only metal dust-exposed workers were followed along the working week to determine the best time of collection. Metal analyses were performed with inductively coupled plasma mass spectrometry (ICP-MS). Analytical methodology was tested using an EBC sample pool for several occupationally exposed metals: potassium, chromium, manganese, copper, zinc, strontium, cadmium, antimony, and lead. Metal contents in EBC of exposed workers were higher than controls at the beginning of the shift and remained augmented throughout the working week. The results obtained support the establishment of EBC as an indicator of pulmonary exposure to metals.

Assessment of exposure to metals in lead processing industries

“…Moreover, the use of a non-invasive method such as the EBC collection allows continuous, repetitive measurements, without adverse reactions to the donor, breaking the boundaries associated with invasive methods, such as broncho-alveolar lavage or even blood draw. This is not only a positive trait for the study of biomonitoring, but also fitted for occupational settings and its demanding requirements, like number of samples and analytical costs (Félix et al, 2012). Also, it is important and advisable that, for an informative monitorization, the profile of the environmental concentration levels in the workplace are evaluated.…”

“…For this ordination design, Cr, Ni, Cu, Sb and Pb were the analytes used (the descriptors), following the criteria of elements determined with a good degree of confidence in EBC (Félix et al, 2012) and the analytes common to both analyses (APM in filters and EBC).…”

“…Goldoni et al, 2004;Nawrot et al, 2008;Almeida et al, 2010;Félix et al, 2012). This occurs, not only due to the ineffectiveness or inexistence of equipment that promotes the extraction of particles or protects the workers individually, but also to the negligence of the subject himself.…”

“…The two sampling periods were chosen as the most representative of the exposure through the 5-day period of work. EBC aliquots were pipetted into polypropylene containers, previously cleaned with HNO 3 suprapur (20%, v/v) and acidified with 3% of the same solution, prior to storage at −80 • C, according to the method described in Félix et al (2012).…”

“…Exhaled Breath Condensate (EBC) has been progressively considered a potential bioindicator of exposure especially fitted to occupational assessments due to several features: (1) it is noninvasive; (2) quickly collected; (3) representative of the organ of direct contact with the toxicant (the lungs); (4) it is not aggressive for the subject, allowing the possibility of repeated collections; (5) and easily analysed, without complex protocols of sample preparation (Hunt, 2002;Goldoni et al, 2004;Caglieri et al, 2006;Cao and Duan, 2006;Almeida et al, 2010;Gube et al, 2010;Hoffmeyer et al, 2011;Félix et al, 2012).…”