Are metals in exhaled breath condensate and urine associated with oxidative/nitrosative stress and metabolism-related biomarkers? Results from 303 randomly selected Parisian subway workers

Elevated metal levels in EBC and urine are associated with altered bronchopulmonary metabolites and increased systemic oxidative stress. While Ba and Ti may originate from brake wear, other metals identified in EBC and urine are not clearly related with subway particles and may be from non-occupational sources. Smoking showed a stronger relationship with the workers' oxidative stress status than occupation.