Uptake, translocation and health risk assessment of nonylphenol in vegetables under reclaimed water irrigation

Nonylphenol (NP) is one of the typical endocrine-disrupting chemicals (EDCs), which can be harmful at very low concentrations. Municipal sewage and reclaimed water are its two main sources. EDCs can enter into the soil with reclaimed water irrigation and accumulate in plants, causing environmental and human health risks. The occurrence and migration of NP in soil-crop systems were studied by pot experiments of lettuce and eggplants simulating long-term irrigation with reclaimed water. The health risks were also evaluated. The experiments set treatments with different initial soil NP concentrations (0.28–6.42 mg/kg) and soil moisture (60%–90% field water capacity [FC]). After harvest, the NP in edible parts of lettuce and eggplants were 35.80–54.30 and 15.45–23.38 μg/kg, respectively. The residual amounts of NP in the soil-lettuce system and soil-eggplant system were limited with the residual rates of 0.9%–24.4% and 0.3%–14.5%, respectively. The results showed that the lettuce and eggplant tissues had the highest bioconcentration factors (BCFs) in 75% FC and the translocation factors (TFs) tended to decrease with the initial soil NP contents increased. The noncancer hazard quotients (HQ) for adults and children exposed to NP had the order of 10⁻⁵, which showed little health risk for reclaimed water irrigation.