**1. Introduction**

Organochlorine pesticides are well known by the scientific literature to be persistent in the environment, toxic for wildlife and potential dangerous for humans since the publication of the famous volume "Silent Spring" by Rachel Carson in 1962 [1]. Due to their massive indus‐ trial production and commercialization for various human purposes, these chemicals have reached concentrations in worldwide environments that are able to significantly affect ter‐ restrial and marine wild species [2], remote world habitats [3] including the remote deep-sea [4], and protected species listed in the IUCN Red List of Threatened Species [5]. Actual con‐ centrations are able to severely affect trophic webs [6] and top-predators [7; 8]. As animal, humans are not excluded by the effects of pollution and concerning these compounds, feed‐ ing represents the principal and worldwide diffuse exposure mechanism for human popula‐ tions rather than inhalation and dermal contact [9; 10; 11; 12]. In spite of that, only in USA, chemical industry produces about 70,000 new products and organic chemicals accounted for the greatest share of production (364.2 million tons) in 1997 [13].

The continuous research of new substances able to cover the great request from engineering, chemistry, pharmaceuticals, medical, commercial and social activities led to the direct and indirect release in environment and the consequent exposure of living organisms to new compounds. Once released in the environment, new chemicals interact with the abiotic and biotic matrices producing mixture composed by pure chemicals which auto-interact, their metabolites and/or reaction and degradation by-products. These mixture are characterized by a progressive increase of complexity and by a clear geographical footprint with percen‐ tages of chemical composition that are dependent both by physico-chemical properties of

© 2013 Renzi; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Renzi; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

compounds making the mixture and latitude/altitude of the geographical area considered [14]. Unluckily the effects induced by pure compounds on non-target species are frequently unknown at the time of their commercialization as well as possible by-products which are produced by the interaction with the environment. Usually, undesirable consequences of new synthesized chemicals are discovered many years later their distribution in commerce, often dramatically. This is the well-known case of the pesticide dichloro-diphenyl-trichloro‐ ethane (DDT) largely used to control malaria diffusion and publicized before 1970' as "the best friend of housewives in controlling pests".

The following paragraphs aims to summarized actual knowledge on PFCs and PBDEs prin‐

Perfluorinated Organic Compounds and Polybrominated Diphenyl Ethers Compounds – Levels and...

http://dx.doi.org/10.5772/53835

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PFCs and PBDEs include molecules characterized by a similar chemical formula but also by very different physico-chemical properties. As consequence of the structural dissimilarities, differences concerning environmental distribution dynamics, and levels in abiotic and bio‐ logical matrices are observed among PFCs and PBDEs congeners. Furthermore, the ecotoxi‐ cological risk associated to the diffusion of these persistent organic pollutants could be notably dissimilar. In fact, physico-chemical properties of molecules influence possible ad‐ verse effects on non-target biological communities. In addition, observed toxicity is notably affected by the interaction among considered chemicals and environmental matrices caused by the photo-chemical deterioration and the production of metabolites during microbial bio‐

Concerning chemicals of ecotoxicological interest, perfluorinated organic compounds (PFCs) are of particular emerging interest due their documented presence both in wildlife's tissues

PFCs are anionic, and fluorine-containing surfactants (both soluble in water and oil) and are applied for a large industrial and commercial employment to produce surfactants, lubri‐ cants, paints, polishes, food packaging, and fire-fighting, foams propellants, agrochemicals,

Their structure consisting of a fluorine atom with which all hydrogen atoms from the linearalkyl chain, which is a hydrophobic group, are replaced. Physico-chemical properties of PFCs favour the occurrence of long-range transport dynamics, as they are more volatile than

Among PFCs, perfluorooctanoic acid (PFOA) and perfluoroctanesulfonic acid (PFOS) repre‐

Salts of perfluorooctanoic acid (PFOA, C8HF15O2) have been used as surfactants and process‐ ing aids in the production of fluoropolymers, and these salts are considered critical to the production of certain fluoropolymers and fluoroelastomers [28]. The functional chemical structure is C7F15COOH and for this reason tends to behavior like an acid dissociating as fol‐

Perfluorooctane sulfonate (PFOS; C8HF17O3S even in this case it dissociates as follows:

cursor for the synthesis of other molecules [26] such as fluorinated surfactants and pesti‐ cides (Abe and Nagase*.,* 1982 in [29]). Perfluoroalkanesulfonate salts and

) evidences an excellent chemical and thermal stability and is a chemical pre‐

cipal characteristics including environmental levels and toxicity on biota.

**2. Physico-chemical properties of considered molecules**

degradation phenomena.

and human blood PFCs [25].

chlorine or bromine analogues.

 + H+ .

lows: C7F15COO-

C7F17SO3 - + H+

**2.1. Perfluorinated organic compounds (PFCs)**

adhesives, refrigerants, fire retardants, and medicines [26; 27].

sents the principal compounds of environmental concern.

Persistent organic pollutants (POPs) are characterized by molecular stability, high persistence due to the resistance to natural degradation processes derived by physical (i.e. temperature or photo-degradation), chemical (i.e. redox and acid-basic reactions, chemical interactions), and biological (i.e. metabolic or microbial deteriorations) aggressions. As reported by the Europe‐ an Community [15], to be classified as "persistent", chemicals must evidence a half-life in water superior than two months and in sediments/soils superior than six months.

POPs concentrate in environment for a very long time and, due to their vapor pressure <1000 Pa and a half-life >2 days in atmosphere, evidence long range transport reaching, also, remote areas [16]. These chemicals usually are low water soluble but evidence a great affinity towards lipids and tend to accumulate in sedimentary organic matter and biological tissues affecting the trophic web along which tend to biomagnificate [17]. Chemicals characterized by logKow >5 and by a bio-concentration factor (BEF) >5,000 are considered "bioaccumulable" [15]. POPs are not biologically inert, on the contrary, they actively interact with physiological biochemistry of species inducing toxicity on wildlife species and humans.

Among POPs, perfluorinated organic compounds (PFCs) and polybrominated diphenyl ethers (PBDEs) are known as "emergent pollutants". PFCs and PBDEs are recently commercialized chemicals of particular ecotoxicological concern which are relatively little described by the lit‐ erature [18]. PFCs and PBDEs increased levels during the latest decades both in environments and wildlife. Several studies have assessed them in a wide range of organisms [19], including humans [20; 21], from low latitude regions to remote areas, suggesting atmospheric transport of volatile precursor compounds and/or transport in ocean currents [22; 23; 24].

This chapter will focuses:


The following paragraphs aims to summarized actual knowledge on PFCs and PBDEs prin‐ cipal characteristics including environmental levels and toxicity on biota.
