Identification and Prioritization of Emerging Organophosphorus Compounds Beyond Organophosphate Esters in Chinese Estuarine Waters

Organophosphorus compounds (OPCs) pose potential hazards
to human
health and aquatic ecosystems. However, limited knowledge of emerging
OPCs beyond organophosphate esters (OPEs) hinders a thorough understanding
of the environmental occurrence and exposure risks. Through target,
suspect, and nontarget screening analysis, 64 OPCs were successfully
identified in Chinese estuarine waters, including 24 known OPEs and
40 emerging analogues (i.e., quaternary phosphonium, phosphine oxide,
organophosphonate, and organothiophosphate esters). Domestic wastewater
and agricultural and industrial discharges were factors influencing
the OPC distribution patterns. In particular, quaternary phosphoniums
and phosphine oxides accounted for over 50% of the total OPC loading
in the Yellow and Jia Rivers, which were likely polluted by phosphorus-related
industries. Risk quotient (RQ) calculations showed that tetrabutylphosphonium
contributed the most to algae toxicity due to the biocidal effects
of onium salts, while chloroalkyl OPEs dominated the ecological risks
for daphnia and fish. The multicriteria decision analysis approach
was further introduced for relative chemical ranking by considering
the variations in hazard criteria of environmental occurrence, fate,
and toxicity of the OPCs. The results indicate that aryl phosphoniums
and aryl phosphine oxides have a hazard priority similar to that of
the OPEs and, therefore, require more attention.