Organophosphate Esters(OPEs) In Foodstuffs And Indoor Dust Of Nanjing:Occurrence,Human Exposure,and Risk Assessment

In recent years,as an important class of promising substitutes for regulated flame retardants,organophosphate esters（OPEs）consumption continues rapid growth.They have been categorized as emerging environmental contaminants that may cause harm to the environment and human health,attracting more and more public attention.Dietary intake and dust inhalation are considered as two important pathways for human exposure to OPEs.Therefore,this study focuses Nanjing which is one of the most representative cities among the major production and consumption areas of OPEs in China,measuring OPEs in foodstuffs and indoor floor dust from Nanjing and assessing human exposure risk.For foodstuffs,nine food categories（n=105）were collected from local supermarkets according to dietary habit of Nanjing residents.Nine of eleven target OPEs in foodstuffs were measurable above the method limits of quantifications.2-ethylhexyl-diphenyl phosphate（EHDPP）and triethyl phosphate（TEP）were the predominant OPEs,and sweets were contaminated most severely by OPEs.The levels of OPEs in“processed foods”were significantly higher than those in“non-processed foods”.For indoor floor dust,fifteen OPEs were investigated in floor dust samples collected from six types of indoor spaces in Nanjing.Ten OPEs consisting mainly of EHDPP and tris（1,3-dichloro-isopropyl）phosphate（TDCIPP）were detected.4-biphenylyl diphenyl phosphate（4-BPDP）and tris（2-biphenyl）phosphate（TBPP）were first detected in environmental samples.Floor dust collected from electronic product maintenance centers contained the richest OPE contaminants.Daily per capita dietary intakes ofΣ₉OPEs for Nanjing adult residents was estimated to be 44 ng/kg BW/day,that was mainly contributed by cereals and tris（2-chloroethyl）phosphate（TCEP）and TEP.Daily per capita intakes via floor dust ingestion to be 1371,754 and 1241pg/kg BW/day for electronic engineers,undergraduates,and graduate students,respectively.Compared with the two OPEs human exposure pathways,dietary intake exposure does were dozens of times higher than the dust ingestion exposure does.There were almost not deleterious effects of health caused by OPEs to adults exposed through the diet or indoor floor dust.