Concentrations of Urinary 8-Hydroxy-2’-deoxyguanosine and 8-isoprostane in Women Exposed to Woodsmoke in a Cookstove Intervention Study in San Marcos, Peru

Abstract

Background: Nearly half of the world’s population is exposed to household air pollution (HAP) due to long hours spent in close proximity to unvented cooking fires. Aims: To investigate whether woodsmoke exposure induces oxidative stress by examining the relationship between woodsmoke exposure and biomarkers of DNA oxidation (8-hydroxy-2’-deoxyguanosine [8-OHdG]) and lipid peroxidation (8-isoprostane) among control and intervention stove users. Methods:We conducted HAP exposure assessment within the framework of a community-randomized controlled trial of 51 communities in San Marcos Province, Cajamarca Region, Peru.The first morning urine voids after 48hr HAP exposure assessment were taken from a subset of 45 control and 39 intervention stove users, for whom PM2.5 and/or CO data were available, were analyzed for 8-OHdG and 8-isoprostane. Control households used a number of stoves including open fire and chimney stoves while intervention households used study-promoted OPTIMA chimney stoves. General linear models and correlation analyses were performed. Results: Creatinine corrected urinary oxidative stress biomarkers ranged from 11.2 to 2270.0 µg/g creatinine (median: 132.6 µg/g creatinine) for 8-OHdG and from 0.1 to 4.5 µg/g creatinine (median: 0.8 µg/g creatinine) for 8-isoprostane among all study subjects (n=84).After controlling for the effects of traffic in the community and eating food exposed to fire among all subjects, cooking time was weakly, but positively associated with urinary 8-OHdG ( r=0.29, p=0.01, n=80). Subjects’ real-time personal CO exposures were negatively associated with 8-OHdG. 48hr time integrated personal PM2.5 was negatively, but marginally associated with urinary 8-isoprostane (r=-0.21, p=0.09, n=69) after controlling for the effect of distance of homes to the road. Conclusion: Results suggest that there is sustained systemic oxidative stress in terms of 8-OHdG among these Peruvian women chronically exposed to wood smoke.