Rethinking alternatives to fluorinated pops in aqueous environment and corresponding destructive treatment strategies

Journal Pre-proof

Rethinking

alternatives

fluorinated

pops

aqueous

environment and corresponding destructive treatment strategies

Yuxin

Zeng,

Yunrong

Dai,

Lifeng

Yin,

Jun

Huang,

Michael

Hof

fmann

PII:

S0048-9697(24)04348-1

DOI:

https://doi.or

g/10.1016/j.scitotenv

.2024.174200

Reference:

OTEN 174200

To appear in:

Science of the T

otal Envir

onment

Received date:

3 February 2024

Revised date:

25 May 2024

Accepted date:

20 June 2024

Please

cite

this

article

as:

Zeng,

Dai,

Yin,

al.,

Rethinking

alternatives

fluorinated

pops

aqueous

environment

and

corresponding

destructive

treatment

strategies,

Science

the

Total

Envir

onment

(2023),

https://doi.or

10.1016/

j.scitotenv

.2024.174200

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Journal Pre-proof

Rethinking

alternatives

fluorinated POPs

in aqueous environment

and

orresponding

destructive

treatment s

trategies

xin Zeng

, Yunrong Dai

Lifeng Yin

Jun

Huang

Michael R. Hoffmann

State Key Laboratory of Water

Environment Simulation, School of Environment, Beijing Normal

University, Beijing 100875, P. R. China

School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing,

100083, P. R. China

State Key Joint

Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing

Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), School of Environment,

POPs Research Center, Tsinghua University, Beijing 100084, China

Department of Enviro

nmental Science & Engineering, California Institute of Technology,

Pasadena, CA, 91125, United States

uxin Zeng

, E

mail:

yxzeng@mail.bnu.edu.cn

Yunrong Dai, E

mail:

iyr@cugb.edu.cn

Lifeng Yin, E

mail:

lfyin@bnu.edu.cn

un H

uang,

mail:

huangjun@mail.tsinghua.edu.cn

Michael R. Hoffmann

mail:

mrh@caltech.edu

Corresponding authors: L. Yin and J. Huang

mail addresses: lfyin@bnu.edu.cn (L. Yin), huangjun@mail.tsinghua.edu.cn (J. Huang).

Journal Pre-proof

Abstract

Alternatives are

being

developed

to replace

fluorinated

ersistent organic pollutants

(

POPs

) listed in

the Stockholm Convention

bypass

environmental regulations, and overcome enviro

nmental risks

However, t

he extensive usage of

fluorinated POPs

alternatives has revealed potential risks

such as high

exposure levels, long

range transport properties, and physiological toxicity

. Therefore, it is imperative

rethink

the alternatives and the

treatment technolog

ies.

This review aims to

consider

the existing

destructive

technologies

for completely eliminating

fluorinated POPs alternatives

from the earth

based

on the updated clas

sification and risks

overview

Herein, t

he types of common alternatives were

renewed

and categorize

, and

their

risks to the environment and organisms were concluded

efficiency, effectiveness, energy utilization, sustainability, and cost of various

gradation technologies

in the treatment of

fluorinated POPs alternatives

were

review

ed and

evaluated.

Meanwhile,

the reaction

mechanisms of

different

fluorinated POPs alternatives

are systematically generalized

and t

correlation between the structure of

alternatives

and

the

degradation characteristics was discussed

providing

mechanistic insights

for their removal from the environment. Overall, the review

supplie

s a

theoretical foundation

and

reference

for the control and treatment of

fluorinated POPs alternatives

pollution.

Journal Pre-proof

raphical abstract

eyword

luorinated POPs

lternatives,

classification,

risks

destructive

reatment

echnology

mechanisms

Journal Pre-proof

1 I

ntroduction

Per

and polyfluoroalkyl substances (PFASs) are defined as substances containing at least a

perfluorinated methyl group (

) or a perfluorinated methylene group (

)

(Schymanski et al.

2023)

ue to large number of C

F bonds, PFASs possess exceptional stability, surface activity, heat,

and acid resistance, leading to their extensive use in electronics, textiles, food packaging, and fire

extinguishing agents

(Glüge et al. 2020, Zhang et al. 2023b

)

Perfluorooctane sulfonate (PFOS) and

perfluorooctanoic acid (PFOA)

re the two most extensively used legacy PFASs

(Hu et al. 2023)

, but

their prevalent utilization has also raised concerns because they have been widely detected in

environmental media

(

ig. 1

), and characterized of biological persistence

bioaccumulation, and

toxicity

(Dai et al. 2023, Xu et al. 2021)

ig. 1

The PFAS life cycle

Reprinted with permission from

(Evich et al.)

. Copyright

(2022)

American Association for the Advancement of

Science

The widespread and environmental hazards of pollution by PFASs have attracted attention and

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triggered regulatory actions. In 2009, PFOS were added to the list of ‘‘persistent organic pollutants

(POPs)’’ under the Annex B of the Stockholm Conventio

(Wang et al. 2009)

, followed by PFOA and

its salts in 2019

(UNEP 2019)

. Since 2021, perfluorohexane sulfonic acid (PFHxS), along with its salts,

and PFHxS

related compounds, has also been listed

(Zhong et al. 2022)

. The US Environmental

Protection Agency (EPA) has been proposing to designate PFOA and PFOS, including their salts and

structural isomers, as hazardous substances. EPA has also announced National Primary Drinking Water

Regulation for PFOA and PFOS, and established legally enfor

ceable levels of 4.0 ng/L for each. The

use of C9−C14 p

erfluoroalkyl carboxylic acid

s (PFCAs) will also be banned by European Union in

2023

(Rüdel et al. 2022)

To address the restrictions on traditional PFASs, various alternatives have been developed, suc

as hexafluoropropylene oxide dimer acid/ammonium salt (tradename: HFPO

DA/GenX), 6:2

perfluoroalkyl ether sulfonic acid (6:2 Cl

PFESA,

tradename

: F

53B), and hexafluoropropylene oxide

trimer acid (HFPO

TA). These alternatives are used extensively in meta

l plating and fluoropolymer

processing

(Wang et al. 2019b)

. However, s

ince the valuable properties of

fluorinated POPs

mainly

come from the C

F chain structure, most of

alternatives have been developed and implemented

based

on this irreplaceable characteri

stic and not undergone essential structural changes

(Li et al. 2023c,

Wen et al. 2023)

. Like their predecessors, these alternatives also exhibited environmental persistence

and bioaccumulation potential

(Galloway et al. 2020)

. GenX, F

53B, and HFPO

TA hav

e been found

in aquatic and atmospheric environment worldwide, including in the United States, Germany, the

United Kingdom, China, and South Korea

(Lin et al. 2016, Pan et al. 2018)

Additionally, the emerging

fluorinated alternatives have the capacity to

accumulate in living organisms

(Gebbink and van

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Leeuwen 2020)

Some are even more bioaccumulative and hazardous than PFOA and PFOS

(Pan et

al. 2020, Shi et al. 2016)

Efforts to mitigate the impact of fluorinated alternatives have focused on two main treat

ment

categories: separative and destructive processes

(Wanninayake 2021)

. Separative processes, including

coagulation, sorption,

and

membrane technologies, concentrate and separate pollutants from

environmental media but do not degrade them completely and

often require further treatment for

contaminated agents or materials

(Gagliano et al. 2020)

. In contrast, destructive techniques such as

electrocatalysis, photocatalysis, hydrothermal liquefaction, and sonolysis, have the capability of

breaking down the mo

lecular structures of pollutants and transforming fluorinated alternatives into

non

toxic small organic molecules or inorganic substances. H

owever

, the mechanisms and pathways

of these degradation processes are not fully understood.

Fluorinated POPs are cl

ear targets of the Stockholm Convention, but replacing them with other

substances introduces new environmental challenges. Identifying effective treatment technologies for

these alternatives, especially in aquatic environments, is a major focus. This revie

w “re

think

” the

differences in chemical structure between alternatives to fluorinated POPs and PFAS, as well as the

environmental risks, chemical stability, degradation techniques and derived reaction mechanisms that

such differences entail. The types of c

ommon alternatives were updated and classified, and risks to the

environment and organisms were concluded objectively, revealing the necessity for effective

degradation technologies. The study compares various degradation methods based on efficiency,

effec

tiveness, energy use, sustainability, and cost, and explores the mechanisms behind these processes,

offering insights for improving destructive treatments.

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Categorization

alternatives

fluorinated

POPs

or the purpose of this review, the term “

alternatives to fluorinated POPs

” refers to the

substances

that

can

functionally substitute

the

legacy

PFAS which have been

listed in the POPs inventory

and

phased out of production

(such as

PFOS

PFOA

and PFHxS),

and can

serve as

their

replacements in

domestic and industrial u

sage.

Since

unction

are

highly determined by structure

most alternatives

still

retain

a relatively large number of

high

energy carbon

fluorine bonds

to meet

the

need

for stability,

so f

luorinated alternatives

ccount for a large portion

of replacements

Simultaneously, two main

strategies were employed to

reduce persistence and increase degradability

. One is to

shorten

the

perfluoroalkyl chains

and r

educe the number of C

F bonds to a certain extent

to lower the

persistence

and reduce half

life

(Nian et al. 2022)

. The other is to modify

the perfluoroalkyl chains

incorporating specific groups

or convert to ring structure to soften the molecular and

decreas

the

recalcitrance

(Wang et al. 2015)

ommon alternatives

to fluorinated POPs

can be

categorized

show

n in

Fig.

The chemical formula, structural formula, CAS number and application fields are

shown in

Table 1

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ig.

Cate

gorization

of commercial

alternatives to fluorinated POPs

2.1

horten

PFASs

To develop

eco

friendly replacements, the chief

strategy is to shorten the

erfluoroalkyl

chain,

because chain length of C8 and longer are more likely to

bioaccumulat

e and

have more potent

toxicity

(Renner 2006)

Since 2000, companies from E

urope and America have

launched

researches and

developed products based on C4 chemistry

(Guo et al. 2008, Wang et al. 2013b)

Short

chain

fluorochemical

s such as

perfluorobutane sulfonate

(PFBS) have been firstly used by

3M Corporation

in place of PFOS in

its Scotchgard stain repellents since June 2003

(Renner 2006)

series of

new

fluorosurfactants

based on PFBS were developed, including

Scotchgard PM

492

with strong

decontamination function

Scotchgard PM

930

with

stain resistance

Scotchgard PC

226

with

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moisture

absorbing properties

(Guo et al. 2008, Renner 2006)

. Since 2011,

Daikin

company

have used

ammonium perfluorohexanoate (APFHx) as polymerization processing aids

. P

erfluorohexane sulfonyl

fluoride (PHxSF, C

based deri

vatives

were also produced

in China and Italy as alternatives

in surface treatment

(Wang et al. 2013b)

. However,

PFHxS

alternatives

gradually

withdraw

from the market

due to the restriction of

Stockholm Convention

(Zhong et al. 2022)

2.2

bonded

luorinated organic

lternative

can also be created

ncorporating

ether

bonds

the straight fluorocarbon chain

which are

supposed to break

down

eas

ily

than PFOS and PFOA

and get

the

biodegradability

improve

(Wang et al.

2019b)

erfluoropolyethers (PFPEs)

refer to a novel

class of

fluorinated compound

that introduce one

or more ether groups into the carbon chain

ncluding

perfluoroalkyl

ether sulfonic and carboxylic

acids

(PFESAs

and

PFECAs)

(Li et al. 2023b, Xu et al.

2021)

Additionally, by partially replacing

fluorine atoms with either chlorine or hydrogen atoms within PFESAs, novel polyfluorinated

compounds have emerged and found widespread application

For

instance

China has extensively

adopted the use of 6:2

PFESA (tradename: F

53B) as an alternative to PFOS for more than four

decades

(Wang et al. 2013a)

. F

53B serves as an effective chromium mist suppressant

accounting for

over

30% of the total production volume in China electroplating industry

tons

)

(Ti et al. 2018)

Moreover, 8:2

PFESA

often the

product of the process of producing 6:2 Cl

PFESA

(Li et al.

2018)

As for

PFECA

s, c

ommercially available products include:

perfluoro

[(3

methoxy

propoxy)

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propanoic acid]

(

radename

ADONA)

xafluoropropylene oxide dimer acid

ammonium salt

(

tradename

HFPO

GenX)

Difluoro[1,1,2,2,

tetrafluoro

(pentafluoro

ethoxy)] ethoxy acetic

acid

(

tradename

EEA)

, and

polymer

hexafluoropropylene oxide

(HFPO)

EEA and ADONA

serve

alternatives to PFOS

in role of

emulsifiers

during

the

production

of fluoropolymers

polytetrafluoroethylene (PTFE)

(Gordon 2011)

he ammonium salt of HFPO

, known as

GenX,

has been

applied as a processing aid in the synthesis of fluorinated chemica

fluoropolymer

and

resin

s since 2009

(Chen et al. 2020, Kancharla et al. 2022)

. As

a new

generation replacement for PFOA

GenX has

an annual production volume of 10

–

100 tons in Europe

(Wang et al. 2019b)

. I

ts homologue,

HFPO

trimer acid (HFPO

TA), was recommended by the Chinese government to replace PFOA in the

production of fluorinated resin

(Bao et al. 2020)

Besides,

HFPO

TA and

HFPO

tetramer

acid

(

HFPO

TeA

) can

also serve

as additives

the production of fluorinated comp

ounds

(Ke et al. 2020, Sun et al.

2023)

Besides

, perfluoro

3,5,7

trioxaoctanoic acid (PFO3OA), perfluoro

3,5,7,9

tetraoxadecanoic

acid (PFO4DA)

and perfluoro

3,5,7,9,11

pentaoxadodecanoic acid (PFO5DoDA)

have also been

used

PFOA alternatives

in fluoro

polymer resin manufacturing

(Sheng et al. 2018, Zhang et al. 2023a)

2.3

Hydrogen

substituted

PFASs

Another class of emerging fluorine

alternative

fluorotelomer sulfonic acids (FTSAs)

which is

prepared by using fluoropolymer alcohols as

precursor materials and introducing H atoms to reduce

the number of C

F bonds

(Wen et al. 2023)

Among them

6:2 FTS

2 FTS

is the most widely

used,

which

is formed when fluorine substituents on

carbon and

carbon atoms of the PFOS molecule are

replace

d with hydrogen.

The 6:2 FTSA have been in commerce in the US since at least the 1970s

(Field

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and Seow 2017)

In Europe, 6:2 FTSA

s commonly used as a substitute for PFOS, employed as a

surface treatment

agent

for metal and plastic components

(Wei et al.

2018b)

, as well as an emulsifier

in the polymerization of fluorinated monomers

(Urtiaga et al. 2018)

In the Japanese chromium plating

industry,

6:2 FTSA

s utilized as a replacement for PFOS and added to the electrolyte to minimize

the formation of Cr

aerosols

(Zhuo et al. 2014)

2.4

Other alternatives

Additionally,

alternatives

with

complex structure

have also been developed as substitutes to

fluorinated POPs

Sodium

perfluorous nonenoxybenzene sulfonate (OBS)

with a benzene ring

moiety

, a

carbon

carbon double bond

and a ether bond

was first produced

a Japanese company (Neos)

since 1980s

and now have also been used as the alternative to PFOS

the field of

steel plate cleaning,

photographic film

printing

, and

fluoroprotein fire

fighting foams

oduction

(Wang et al. 2019a, Xu

et al. 2021)

As a cost

effective surfactant

OBS has been

extensively

manufactured,

with an estimated

total production volume of about 3500 t per year in China

(Bao et al. 2017)

erfluoroethylcyclohexane

sulphonate (PFECHS)

, with a

six

membered ring structure

has also been considered as a potential

replacement for PFOS

(Mahoney et al. 2023)

, which

was synthesized by 3M

and has been

mainly

produced

as an erosion inhibitor in aircra

ft hydraulic fluid

(De Silva et al. 2011, Niu et al. 2019)

. Some

fluoride

free

alternatives

(e.g., silicone polymers, siloxanes and dendrimers)

have also been developed

to functionally replace

fluorinated POPs

(Manojkumar et al. 2023)

However, l

oss of sta

ble C

F bonds

and

fundamental changes in structure

lead to their

lower performance

practical application

(Manojkumar et al. 2023)

which

will not be discussed in depth in this

review.

Journal Pre-proof

able

List of

common

alternatives

fluorinated POPs

, together with their abbreviation,

hemical

ormula, CAS number

structure

and application field.

Abbreviatio

Chemical formula

CAS

number

Chemistry structural formula

Application

field

hort

chain PFASs

PFBS

(CF

)

375

luorosurfactan

Perfluoropolyethers (PFPEs)

6:2 Cl

PFESA/F

53B

ClCF

(CF

)

O(CF

)

73606

lectroplating

EEA

O(CF

)

OCF

COOH

80153

–

Fluoropolymer

manufacturing

HFPO

GenX

(CF

)

OCF(CF

)COO

62037

luorinated

chemicals

manufacturing

HFPO

(CF

)

OCF(CF

)CF

OCF(CF

)CO

13252

luorinated

chemicals

manufacturing

HFPO

TeA

(CF

)

O(C

OCF(CF

)CO

65294

luorinated

chemicals

manufacturing

ADONA

O(CF

)

OCHFCF

COO

958445

Fluoropolymer

manufacturing

PFO3OA

(

OCF

)

COO

39492

luoropolymer

resin

manufacturing

PFO4DA

(

OCF

)

COO

39492

luoropolymer

resin

manufacturing

PFO5DoD

(

OCF

)

COO

39492

luoropolymer

resin

manufacturing

Fluoropolymer alkyl acids

(FTSA)

6:2

FTSA/6

FTS

(CH

)

59587

Fluorinated

chemicals

producing

decorative

plating

chromium

plating

Other a

lternatives

70829

teel plate

cleaning,

photographic

film

printing

Journal Pre-proof

PFECHS

646

ircrafts

isks of

alternatives

fluorinated

POPs

.1 Exposure levels

Although

fluorinated POPs

, as regulated by the Stockholm Convention, are no longer or rarely

mass

produced and used, their alternatives are

rapidly taking up their “niche”.

Recently, due to

the

widespread

usage of

fluorinated

alternatives in industrial and daily life, their presence has been

extensively

permeate

aqueous

environment including surface water, wastewater, groundwater,

drinking water,

and

sea

water all over the world

(Manojkumar et al. 2023, Ruan et al. 2015, Wang et

al. 2021b, Xu et al. 2021, Zhang et al. 2023b)

, highlighting the emerging environmental pollut

ion

issues.

Wastewater, as the direct receptor of a multitude of pollution sources, manifests elevated

concentrations of

fluorinated alternatives

compared to other

water

body

The

effluents

Spanish

sewage treatment plant have been found to

contain up

o 305.0 ng L

f PFBS

(Campo et al. 2014)

Similarly, wastewater effluents from treatment plants near an industrial complex in South Korea have

shown PFBS concentrations ranging from

2.4 to 872.0 ng L

(Seo et al. 2019)

In semiconductor

industry

genera

ted photolithography wastewater, PFBS concentrations can reach as high

as 5.2 mg L

and even after treatment, discharge concentrations can still be as high a

s 0.1 mg L

(Lin et al. 2009)

Among various

fluorinated alternatives

, PFBS is the most

commonly detected and widely distributed

in different aquatic environments, entering the water cycle.

PFBS has also been detected in drinking

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water

of China

at concentrations ranging from 0 t

o 4.8 ng L

(Li et al. 2019)

The remarkable durability of

fluor

inated alternatives

makes them resistant to degradation in

traditional wastewater treatment processes, leading to their dilution and release into surface water and

groundwater.

luorinated alternatives

are more easily found in surface water and groundwater

near

industrial sources.

In the groundwater of a Fluorochemical industrial park in China, common

alternatives such as PFBS

(0.6

–

2.8 ng L

), 6:2 Cl

PFESA (0.4

–

6.2 ng L

), HFPO

DA (1.6

–

5260.0 ng

), HFPO

TA (3.6

–

4808.0 ng L

), ADONA (0

–

0.02 ng L

), an

d 6:2 FTSA (0

–

4.9 ng L

) h

ave been

detected

(Ding et al. 2022b)

A groundwater survey in Jiangsu Province, China, also found significantly

higher concentrations of PFBS, 6:2 Cl

PFESA, and 6:2 FTSA in groundwater near industrial parks

compared to non

indus

trial areas

(Wei et al. 2018a)

Additionally,

fluorinated alternatives

have

demonstrated long

distance migration, traveling along surface or subsurface flows and ultimately

reaching the ocean.

Seawater samples from estuarine deltas and coastal areas,

nclu

ding

German Bight

(

German)

(Ahrens et al. 2009)

Xiamen Bay

(China

)

(An et al. 2023)

Bohai

Bay

(China

)

(Lin et al.

2022)

and

Mediterranean

(Sánchez

Avila et al. 2010)

have all shown concentrations of

fluorinated

alternatives

exceeding

5.0 ng L

Even

in remote ocean waters such as the Indian Ocean and Pacific

Ocean, and on the surface snow of the Antarctic Plateau, PFBS and HFPO

DA have been detected,

confirming the global spread and dissemination of

fluorinated alternatives

(Han et al. 2022, Shan

et al.

2021, Xie et al. 2020)

hort

chain

alternatives tend to migrate further owing to their better water

solubility and more difficult to be adsorbed by

sediments

(Li et al. 2024)

Wide dispersal of

fluorinated alternatives

has caused

the

entry into

biota

which

have

also

been

increasingly found in

various kind of a

quatic

animals such as

fish,

shrimp

crab

s and

mollusks

(Jin et

Journal Pre-proof

al. 2020, Kaboré et al. 2022)

Besides

, the presence of

fluorinated alternatives

also been

found

invertebrates

bird

s and even

plasma and yolk

of bird eggs

(Bertin et al. 2014, Haukås et al. 2007,

Jouanneau et al. 2022, Miljeteig et al. 2009, Wang et al. 2021a, Wu et al. 2020)

, indicating

that

these

emerging

fluorinated alternatives

have the potent

ial to

transfer to

progeny

through

reproduction

. As

for humans, i

door dust ingestion and fish consumption have been indicated to be important vectors

of exposure

pathway

fluorinated alternatives

(He et al. 2022, Wang et al. 2021b)

. Statistically higher

median serum levels of Cl

PFESAs were observed in high fish consumer

s (93.7 ng mL

) an

d metal

plating workers

(51.5 ng mL

) compared to the background control group (4.8 ng mL

)

(Shi et al.

2016)

. Besides, the detection

of C8

PFESA

in hair

–

9.3 ng g

) or nail (0

–

3.7 ng g

)

samples may

be owing to the direct contact with consumer products treated with

fluorinated alternatives

, such as

personal care products, treated fabrics and food packaging

(Wang et al. 2018)

Biological and human h

ealth

hazard

The development of

alternatives

was intended to reduce the

hazard

s of

fluorinated

POPs

, but

turns out that these measures have not lived up to expectations to some extent.

2023, European

Chemicals Agency (ECHA) prepared a

restriction pr

oposal

on PFASs, in which the hazards of

fluorinated alternatives

were noticed and assessed. Several

fluorinated

have been proved to

show

comparable concerns as

fluorinated POPs

, such as p

ersistence

bioaccumulation

and

toxicity.

2.1

Persistence and bioaccumulation

One of the purposes of the alternative’s development is to lower the persistence of

fluorinated

POPs

in order to reduce the environmental impact, but multiple studies have demonstrated that some

Journal Pre-proof

alternatives may exhibit grea

t recalcitrance and long half

lives under general conditions

(Brase et al.

2021, Cui et al. 2022)

The estimation of renal elimination half

life (median 280 years) and total

elimination half

life (median 15.3 years) of 6:2 Cl

PFESA indicates that it

may be

the most persistent

PFAS

ever

reported

(Pan et al. 2020)

Little PFBS decomposed even after 106 days (1232 h) of solar

irradiation under environmental exposures

(Taniyasu et al. 2013)

The persistence may

further

lead to

the bioaccumulation potential in c

reatures

luorinated alternatives

have been reported to have

comparable octanol

water partition coefficient (K

), bioconcentration factors (BCF), and

bioaccumulation factor (BAF) values as PFOS and PFOA

(Gomis et al. 2015)

implying similar level

of accu

mulation

The BAF values of PFESAs in common carp blood were found higher than those of

lega

PFASs (GenX > PFOA, 6:2 Cl

PFESA > PFOS)

(Pan et al. 2017, Shi et al. 2015)

, indicating

that the insertion of ether oxygen and/or chlorine atoms may increase the

difficulty

metaboliz

ation

in organisms

Several studies have indicated that F

53B can rapidly accumulate in zebrafish embryos,

juveniles, and adults, but its clearanc

e rate was extremely slow

(Deng et al. 2018, Shi et al. 2017, Wu

et al. 2019)

The accumulation of

fluorinated alternatives

in organisms indicates their persistence and

resistance to m

etabolism

, which may cause health risks to biology.

.2.2

Toxicity

The p

otential bioaccumulation

fluorinated alternatives

may cause

and

multifaceted

toxic

effects on function

al organs

in multiple species

(Liu et al. 2023a, Liu et al. 2020a)

Take zebrafish as

an example, the alternatives exposure

may cause similar

physiolog

ical toxicity

fluorinated

POP

s to

liver, heart, immune system, neutral system and so on

(Rericha et al. 2023)

(

Fig.

)

cute exposure

zebrafish embryos to

4.8

mg L

and 9.6 mg L

of PFBS significantly increased the probability of

Journal Pre-proof

pancreatic and caudal fin malformation

delayed swim bladder inflation, impaired vitellogenin

synthesis, and disrupted lipid homeostasis

(Sant et al. 2019)

The exposure of PFBS also s

ignificantly

reduce

d nutrient

reserve

s, especially lipid content, and disrupted the gut

microbiota

of zebrafish

(Hu

et al. 2021)

53B

has

been found to have the potential to induce

immunotoxicity

developmental

toxicity

reproductive toxicity, liver toxicity,

thyroid hormone disruption,

cardiac toxicity and reduce

heart rate in adult zebrafish and their offspring

(Briels et al. 2018, Huang et al. 2022, Shi et al. 2017,

Zhang et al. 2018)

Except for fishes,

fluorinated alternatives

can also cause hazards to mam

mals.

ADONA

could

cause weight loss, liver damage and death in rats

(Wang et al. 2019b)

. U

nder GenX

exposure, mice

showed

a higher incidence of abnormal placenta, while rats

showed

a higher incidence

of decreased maternal thyroid hormone levels

(Chambers e

t al. 2021)

three

year study of 752

women in China

also

found prenatal exposure to PFBS was associated with the disturbance of fetal

gonadotropins as well as free androgen level

(Nian et al. 2020)

From this point of view, human efforts

to completely el

iminate

PFASs

and their analogues have not achieved the intended purpose, whether

fishes, mammals, and even humans are affected by

fluorinated alternatives

. Therefore,

it is

urgent to

implement

control and treatment on the pollution of

fluorinated alternat

ives

and

eliminate

the risks to

environment and organisms.