302
although results have been conflicting. A number of epidemiological investigations
reported links between high level of perfluorooctanesulfonic acid or perfluorooctanoic acid (PFOA) in maternal serum and enhanced BMI of offspring, possibility of
being obese, and low level of serum leptin levels in kids or adults. Particularly,
females are more pronounced to these effects. PFASs possess properties helping in
long-range transport by allowing enough residence time in the atmosphere and
simultaneously they are so reactive that they are easily convertible into carboxylic
acids and other compounds such as fluorotelomer species by undergoing oxidative
reactions.
Keywords Perfluoroalkyl substances · Adipocyte differentiation · Obesogens ·
Fluorotelomer species
Introduction
“Fluorinated substances” is a common term that defines a class of organic and inorganic chemicals that holds at least one fluorine (F) atom, with immensely varied
chemical, physical, and biological effects [1]. Synonyms include “fluorochemicals”
and “fluorinated chemicals.” A subclass of fluorinated chemicals is the extremely
fluorinated aliphatic chemicals that contain one or more C atoms on which all the H
substituents have been exchanged by F atoms, in a way that they possess the
C n F 2n + 1 – functional group. Therefore, these compounds are called “perfluoroalkyl
and polyfluoroalkyl substances” and represented by the abbreviation PFASs. PFASs
and polymers made with the aid of PFASs and surfactants have been extensively
utilized in several commercial and industrial applications since 1950 [2].
Polyfluoroalkyl substances can also be defined as those aliphatic chemicals for
which all hydrogen atoms attached to at least one carbon atom (but not all) and these
hydrogen atoms have been replaced by F atoms, in such a fashion that they have
perfluoroalkyl functional group C n F 2n + 1 – (for example, C 8 F 17 CH 2 CH 2 OH).
Consequently, however the overall chemical conception of “polyfluorination” encircles compounds having “scattered” several F atoms (e.g., in CH 2 FCHFCHFCH 2 OH),
likewise “grouped” ones (e.g., CF 3 CF 2 CH 2 COOH), polyfluorinated substances having minimally one perfluoroalkyl moiety C n F 2n + 1 – are considered that they belong
to PFAS family, as an extensive range of these chemicals have been detected in the
environment, humans, and wildlife due to the increased usage of PFASs and their
release in the environment. The universal extent of such kind of pollution was first
described in wildlife for perfluorooctane sulfonic acid, C 8 F 17 SO 3 H (PFOS) by Giesy
and Kannan [3].
Under suitable conditions, polyfluoroalkyl substances have the capacity to be
transformed biotically or abiotically into PFASs. Such as polyfluoroalkyl substance
C n F 2n + 1 SO 2 NHCH 2 CH 2 OH can break down to PFASs, i.e. C n F 2n + 1 SO 3 H [4, 5]. This
concept was revealed by groups of the scientist who have participated in the
European Union PERFORCE project [6] and some other scientists who have
S. G. Niazi et al.
although results have been conflicting. A number of epidemiological investigations
reported links between high level of perfluorooctanesulfonic acid or perfluorooctanoic acid (PFOA) in maternal serum and enhanced BMI of offspring, possibility of
being obese, and low level of serum leptin levels in kids or adults. Particularly,
females are more pronounced to these effects. PFASs possess properties helping in
long-range transport by allowing enough residence time in the atmosphere and
simultaneously they are so reactive that they are easily convertible into carboxylic
acids and other compounds such as fluorotelomer species by undergoing oxidative
reactions.
Keywords Perfluoroalkyl substances · Adipocyte differentiation · Obesogens ·
Fluorotelomer species
Introduction
“Fluorinated substances” is a common term that defines a class of organic and inorganic chemicals that holds at least one fluorine (F) atom, with immensely varied
chemical, physical, and biological effects [1]. Synonyms include “fluorochemicals”
and “fluorinated chemicals.” A subclass of fluorinated chemicals is the extremely
fluorinated aliphatic chemicals that contain one or more C atoms on which all the H
substituents have been exchanged by F atoms, in a way that they possess the
C n F 2n + 1 – functional group. Therefore, these compounds are called “perfluoroalkyl
and polyfluoroalkyl substances” and represented by the abbreviation PFASs. PFASs
and polymers made with the aid of PFASs and surfactants have been extensively
utilized in several commercial and industrial applications since 1950 [2].
Polyfluoroalkyl substances can also be defined as those aliphatic chemicals for
which all hydrogen atoms attached to at least one carbon atom (but not all) and these
hydrogen atoms have been replaced by F atoms, in such a fashion that they have
perfluoroalkyl functional group C n F 2n + 1 – (for example, C 8 F 17 CH 2 CH 2 OH).
Consequently, however the overall chemical conception of “polyfluorination” encircles compounds having “scattered” several F atoms (e.g., in CH 2 FCHFCHFCH 2 OH),
likewise “grouped” ones (e.g., CF 3 CF 2 CH 2 COOH), polyfluorinated substances having minimally one perfluoroalkyl moiety C n F 2n + 1 – are considered that they belong
to PFAS family, as an extensive range of these chemicals have been detected in the
environment, humans, and wildlife due to the increased usage of PFASs and their
release in the environment. The universal extent of such kind of pollution was first
described in wildlife for perfluorooctane sulfonic acid, C 8 F 17 SO 3 H (PFOS) by Giesy
and Kannan [3].
Under suitable conditions, polyfluoroalkyl substances have the capacity to be
transformed biotically or abiotically into PFASs. Such as polyfluoroalkyl substance
C n F 2n + 1 SO 2 NHCH 2 CH 2 OH can break down to PFASs, i.e. C n F 2n + 1 SO 3 H [4, 5]. This
concept was revealed by groups of the scientist who have participated in the
European Union PERFORCE project [6] and some other scientists who have
S. G. Niazi et al.