Urinary 8-isoprostane and 8-OHdG concentrations in boilermakers with welding exposure.

OBJECTIVE: To investigate the association of exposure to fine particulate matter (PM2.5) with DNA damage and oxidative stress in boilermakers exposed to welding fumes. METHODS: Forty-one workers were monitored over 24 hours during which baseline, postshift, bedtime, and next morning measurements were collected. Twenty-two workers participated as controls. RESULTS: Linear regression was used to model pairwise change in u-8-isoprostane and u-8-OHdG: pre- to postshift, preshift to bedtime, postshift to bedtime, and postshift to next morning. In the models, pre- to postshift change in 8-OHdG was statistically significant, whereas postshift to bedtime change in 8-isoprostane showed an unexpected inverse relationship with PM2.5. CONCLUSIONS: Acute welding exposure is associated with a postshift blunting of systemic inflammation in chronically exposed boilermakers, as measured by 8-isoprostane. The level of oxidative DNA damage as measured by 8-OHdG is less clear.