A global survey of organophosphate esters and their metabolites in milk: Occurrence and dietary intake via milk consumption

The first global survey of organophosphate esters (OPEs) and their metabolites (mOPEs) in milk was carried out in this study. Concentrations of 21 OPEs and 9 mOPEs were measured in 178 milk samples collected from 30 countries located on 5 continents, and the ubiquity of both OPEs and mOPEs was observed in milk. Concen-trations of E21OPEs ranged from 53.3 pg/mL to 4270 pg/mL, with a median level of 367 pg/mL. The median level of E9mOPEs was 153 pg/mL, with a range of 15-7440 pg/mL. No difference was observed among the levels of both E21OPEs and E9mOPEs in milk from the five continents. For the relationship between mOPEs and their parent OPEs, some pairs presented significant and positive correlations, which indicated that they shared similar sources. Estimated daily intakes (EDIs) of OPEs/mOPEs via milk consumption were calculated. Asian countries presented relatively low EDIs, and European and American countries, especially Denmark, the Netherlands, Finland and Argentina, presented high EDIs. Current daily OPE intake via milk consumption for global adult populations was far lower than the corresponding reference dose; however, considering that human intake of OPEs occurs via multiple sources, it is too early to conclude that the intake of OPEs were unable to cause health concerns.

Automated summary

This study conducted the first global survey of organophosphate esters (OPEs) and their metabolites (mOPEs) in milk. The findings showed that both OPEs and mOPEs were prevalent in milk samples collected from different countries on five continents. The concentrations of OPEs and mOPEs in milk did not differ significantly among the continents. The estimated daily intakes (EDIs) of OPEs/mOPEs through milk consumption varied among countries, with higher intakes observed in European and American countries. The current OPE intake through milk consumption for global adult populations was below the reference dose, but it is premature to conclude that OPE intake does not pose health concerns, considering that OPEs can be sourced from multiple sources.