posted on 2023-11-18, 14:35authored byRongcan Chen, Changyue Xing, Guofeng Shen, Kevin C. Jones, Ying Zhu
Organophosphite
antioxidants (OPAs) have been seriously neglected
as potential sources of organophosphate esters (OPEs) in environments.
This study utilizes a modeling approach to quantify for the first
time national emissions and multimedia distributions of triphenyl
phosphate (TPHP)a well-known flame retardantand three
novel OPEs: tris(2,4-ditert-butylphenyl) phosphate
(AO168O), bis(2,4-ditert-butylphenyl) pentaerythritol
diphosphate (AO626O2), and trisnonylphenol phosphate
(TNPP). Emphasis is on the quantitative assessment of OPA source in
China. TPHP has 1.1–9.7 times higher emission (300 Mg/year
in 2019 with half from OPA sources) than AO168O (278 Mg/year),
AO626O2 (53 Mg/year), and TNPP (32 Mg/year), but
AO168O is predominant in environments (63–79%) except
freshwaters. About 72–99% of the studied OPEs are emitted via
air, with 88–99% ultimately distributed into soils as the major
sink. OPA-source emissions contribute 9.5–57% and 4.7–56%
of TPHP masses and concentrations (except in sediments) in different
media, respectively. Both AO168O and AO626O2 exhibit high overall persistence ranging between 2 and 11 years.
Source emissions and environmental concentrations are elevated in
economically developed areas, while persistence is higher in northern
areas, where precipitation and temperature are lower. This study shows
the significance of the sources of OPA to OPE contamination, which
supports chemical management of these substances.