Migration and health risks of nonylphenol and bisphenol a in soil-winter wheat systems with long-term reclaimed water irrigation

Reclaimed water reuse has become an important means of alleviating agricultural water shortage worldwide. However, the presence of endocrine disrupters has roused up considerable attention. Barrel test in farmland was conducted to investigate the migration of nonylphenol (NP) and bisphenol A (BPA) in soil-winter wheat system simulating reclaimed water irrigation. Additionally, the health risks on humans were assessed based on US EPA risk assessment model. The migration of NP and BPA decreased from the soil to the winter wheat; the biological concentration factors (BCFs) of NP and BPA in roots, stems, leaves, and grains all decreased with their added concentrations in soils. The BCFs of NP and BPA in roots were greatest (0.60-5.80 and 0.063-1.45, respectively). The average BCFs of NP and BPA in winter wheat showed negative exponential relations to their concentrations in soil. The amounts of NP and BPA in soil-winter wheat system accounted for 8.99-28.24% and 2.35-4.95%, respectively, of the initial amounts added into the soils. The hazard quotient (HQ) for children and adults ranged between 10(-6) and 1, so carcinogenic risks could be induced by ingesting winter wheat grains under long-term reclaimed water irrigation.