Urinary Organophosphate Esters and Increased Oxidative Stress in Healthy Older Adults: The China BAPE Study

Exposure to organophosphate esters (OPEs) is associated with the development of geriatric diseases. However, the impact of OPEs on oxidative stress, a precursor of geriatric diseases, remains unclear in older adults. Based on the China BAPE study, a panel study with multiple repeated measurements, we collected urine samples from 76 healthy older adults to measure OPEs and oxidative stress markers, aiming to investigate both individual and combined OPE exposures in relation to oxidative stress. Our results indicated that Dibutyl phosphate (DBP), Bis-(2-ethylhexyl) phosphate (BEHP), Bis-(1,3-dichloro-2-propyl) phosphate (BDCIPP), Diphenyl phosphate (DPHP), and Bis-(2-methylphenyl) phosphate (BMPP) exposure were significantly associated with increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), and malondialdehyde (MDA). Household heating status had a modifying effect on these associations. Generalized additive mixed models revealed potential linear and nonlinear associations between OPEs and oxidative stress markers. The quantile g-computation and Bayesian kernel machine regression further found positive effects of OPEs mixtures on 8-OHdG, 8-OHG, and MDA. Weighted distribution analyses identified BEHP as a potentially contributing component affecting oxidative stress. These findings not only illuminate the health hazards of OPE exposures but also aid in understanding the link between OPEs and adverse health outcomes in older adults.