Research progress on organophosphate flame retardant exposure and its effects on skeletal health: a review

Organophosphate flame retardants (OPFRs) are widely used in building materials, electronics, textiles, and other fields due to their excellent flame-retardant properties. However, their unique physicochemical properties, such as high lipophilicity and persistence, lead to their widespread distribution in the environment and bioaccumulation in organisms. Recent studies have shown that OPFRs can enter the human body through various routes, including inhalation, dietary intake, and dermal contact, potentially causing adverse health effects, with increasing concern regarding their impact on bone health. OPFR exposure has been linked to bone health issues such as reduced bone mineral density, osteoporosis, and increased fracture risk. The underlying mechanisms may involve the activation of PPARγ signaling pathways, disruption of thyroid hormones, and inhibition of Hedgehog signaling pathways. This review aims to summarize the physicochemical properties, environmental distribution, human exposure levels, bone toxicity, and potential mechanisms of OPFRs.