Health risk assessment of fluorine in fertilizers from a fluorine contaminated region based on the oral bioaccessibility determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM)

Due to potential adverse effects of excessive fluorine (F), interests regarding considerable accumulation of F in agricultural soils from application of fertilizers are increasing continually. However, less detailed information of hazard and risk of F in fertilizers to human directly by hand-to-mouth pathway can be obtained. Herein, the bioaccessibility of F (F-bio) in fertilizers is determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM), which is developed to detect the behaviour of bioaccessible F in both the whole digestive system and plasma for the first time. Observations of higher F-bio in small intestinal phases (4.35-56.33%), large intestine (1.01-40.52%) and plasma (8.07-66.70%) yielded them as the major phases which are faced with higher exposure risk of F. Compared with phosphate fertilizer, more bioaccessible F was observed in compound fertilizer. Some studied factors, such as sweat and food, yield insignificant influences on F-bio, whereas can affect the exposure estimations of F considerably. Exposure risks based on F-bio of fertilizers should be highly concerned, especially the occupational exposure to local farmers. In a word, more explicit and realistic information of the potential risk of F on human health could be obtained by the introduction of F-bio.