Nontarget Identification of Novel Organophosphorus Flame Retardants and Plasticizers in Rainfall Runoffs and Agricultural Soils around a Plastic Recycling Industrial Park

Abstract

Plastic recycling and reprocessing activities may release organophosphate ester (OPE) flame retardants and plasticizers into the surrounding environment. However, the relevant contamination profiles and impacts remain not well studied. This study investigated the occurrence of 28 OPEs and their metabolites (mOPEs) in rainfall runoffs and agricultural soils around one of the largest plastic recycling industrial parks in North China and identified novel organophosphorus compounds (NOPs) using high-resolution mass spectrometry-based nontarget analysis. Twenty and twenty-seven OPEs were detected in runoff water and soil samples, with total concentrations of 86.0–2491 ng/L and 2.53–199 ng/g dw, respectively. Thirteen NOPs were identified, of which eight were reported in the environment for the first time, including a chlorine-containing OPE, an organophosphorus heterocycle, a phosphite, three novel OPE metabolites, and two oligomers. Triphenylphosphine oxide and diphenylphosphinic acid occurred ubiquitously in runoffs and soils, with concentrations up to 390 ng/L and 40.2 ng/g dw, respectively. The downwind areas of the industrial park showed elevated levels of OPEs and NOPs. The contribution of hydroxylated mOPEs was higher in soils than in runoffs. These findings suggest that plastic recycling and reprocessing activities are significant sources of OPEs and NOPs and that biotransformation may further increase the ecological and human exposure risk.

Discovering Novel Organophosphorus Compounds in Wastewater Treatment Plant Effluents through Suspect Screening and Nontarget Analysis

“…It eluted as split peaks with the same MS/MS spectra, probably due to the presence of isomers with different chloropropyl moieties. BCPCPOPP is reported to be used as an additive and processing aid in polymer production and was recently identified in soil samples around a plastic recycling industry park . The MS/MS spectrum of DEGBBCEP (CL 2a) matched well with the observation of Wang et al (Figure S1d), in which the compound was initially discovered and among the most frequently detected chlorinated alkyl tri-OPEs in Beijing house dust samples .…”

“…Furthermore, we detected three other OPCs in the wastewater samples: diphenylphosphinic acid (DPPA), ethyldiphenylphosphine oxide (EDPPO), and tributylphosphine oxide (TBPO) (Figure S6). Recently, DPPA has been reported in WWTPs, Onondaga Lake, and runoff water around a plastic recycling industry park, due to its extensive use. EDPPO and TBPO were newly identified in the wastewater samples (Figure e).…”

“…A total of 232 suspect OPCs were compiled from the literature ,− and two flame retardant lists on the US EPA CompTox Chemicals Dashboard (see details in Text S4 and Table S3). Besides commonly investigated suspect OPEs, some transformation products and other OPCs such as organothiophosphate esters, organophosphonates, and phosphine oxides were also included in the list.…”

“…This significantly enhanced our understanding of previously unrecognized OPCs. − For instance, Meng et al demonstrated the efficacy of functional group-dependent screening, revealing an abundant OPE bis­(2-ethylhexyl)-phenyl phosphate in indoor dust at levels comparable to or even higher than traditional OPEs. Additionally, eight novel OPCs were identified for the first time in rainfall runoffs and agricultural soils near a plastic recycling industrial park . However, most of these studies mainly focused on halogenated OPCs or OPEs, and there are still large knowledge gaps regarding novel OPC structures as well as their environmental occurrence and impacts.…”

“…Over the past decade, suspect and nontarget screening strategies based on HRMS have uncovered more than 50 OPCs in various environmental matrices . This significantly enhanced our understanding of previously unrecognized OPCs. − For instance, Meng et al demonstrated the efficacy of functional group-dependent screening, revealing an abundant OPE bis­(2-ethylhexyl)-phenyl phosphate in indoor dust at levels comparable to or even higher than traditional OPEs. Additionally, eight novel OPCs were identified for the first time in rainfall runoffs and agricultural soils near a plastic recycling industrial park .…”