A Review of Organophosphate Esters in Aquatic Environments: Levels, Distribution, and Human Exposure

Abstract

Organophosphate esters (OPEs) are increasingly used as flame retardants and plasticizers in various products. Most of them are physically mixed rather than chemical bonded to the polymeric products, leading to OPEs being readily released into the surrounding environment. Due to their relatively high solubility and mobility, OPEs are ubiquitous in the aquatic environment and may pose potential hazards to human health and aquatic organisms. This review systematically summarized the fate and distribution of OPEs in the aquatic environment and the potential effects of OPEs on humans. Data analysis shows that the concentrations of OPEs vary widely in various types of aquatic environments, including surface water (range: 25–3671 ng/L), drinking water (4–719 ng/L), and wastewater (104–29,800 ng/L). The results of human exposure assessments via aquatic products and drinking water ingestion indicate that all OPEs pose low, but not negligible, risks to human health. In addition, the limitations of previous studies are summarized, and the outlook is provided. This review provides valuable information on the occurrence and distribution of OPEs in the aquatic environment.

An overview of the (eco)toxicological effects of flame retardants emerging in water and sediment

“…They may undergo several processes including partitioning and degradation followed by sinking in sediments (Hou et al, 2021). The pathways encompass atmospheric deposition, surface run-off, and precipitation (Wang et al, 2023). PBDEs, NBFRs, and OPFRs production, their leaching from the materials, and improper discharge are major sources of environmental contamination.…”

“…TEHP, 2-ethylhexyl diphenyl phosphate (EHDPP) -Table S2, have a higher tendency to absorb in sediments. Interestingly, OPFRs distribution and concentration may constantly change, due to their complicated migration and transformation processes occurring under the influence of internal water forces (Wang et al, 2023). FRs exhibiting higher vapour pressure, are more likely to volatilise into the atmosphere.…”

“…TCEP, TCPP, and TDCPP) are present in lower concentrations in sediments compared to water. At the same time some of the FRs soluble in water can also be found in sediments, by their combination with plankton, and then fall free (Wang et al, 2023). OPFRs exhibiting lower molecular weight are more likely to be found in water than in sediment.…”