Agriculture Reference
In-Depth Information
13.2 Ecotoxicology at Large
The exposure of nanomaterials in different environmental compartments (water,
soil, and air) may result in their increased bioavailability and accumulation along
food chains (Oberdorster et al. 2004 ; Ramsden et al. 2009 ). Likewise, they can
reach the human body through air, water, and soil; nanomaterials are likely to
interact with other living cells, causing effects unknown in their entirety. In this
sense, the three basic strategies for screening the toxicity profile of nanomaterials,
according to Oberd¨rster et al. ( 2005a ) are:
• Physicochemical
characterization (size,
surface
area,
shape,
solubility,
aggregation)
• Elucidation of the biological studies from in vitro effects
• Confirmation of the effects through in vivo studies
These three points were formulated from the point of view of the potential
effects of nanomaterials in humans. But when an entire ecosystem is taken into
consideration, the question becomes broader and more complex. Despite a growing
body of information about the toxic effects of nanomaterials on humans by direct or
indirect exposure, related environmental impact studies were just in the beginning
(Kahru and Dubourguier 2010 ). The trend, however, is that this assessment increas-
ingly becomes a global concern and is required by regulatory agencies.
The ecotoxicology itself can be comprehended as a science whose core is to
study the contaminants and their effects on components of the biosphere, including
humans (Newman and Zhao 2008 ). It was Ren´ Truhaut who first mentioned the
term “ecotoxicology” in 1959, defining it as “the branch of toxicology concerned
with the study of toxic effects caused by natural or synthetic pollutants for compo-
nents of animals (including humans) vegetable and microbial ecosystems, in an
integral context” (Truhaut 1977 ). The ecotoxicological research has been devel-
oped rapidly due to the environment pollution induced by the rapid industrial
development of that era, permeated by major industrial accidents. Policies have
been developed since then, and ecotoxicology has become a significant part of the
environmental and ecological risk required by these new laws.
Ecotoxicological tests have been developed greatly for aquatic environments. In
this context, Blaise ( 1998 ) classified the development stages of aquatic toxicity tests
in terms of decades: (1) “the dark ages” until the 1950s, (2) the decade of fish
studies in the 1960s, (3) the 1970s regulatory decade, (4) the ecotoxicological
decade in the 1980s, and (5) the decade of microbiotests in the 1990s. More
recently, Kahru and Dubourguier ( 2010 ) designated the decade 2010-2020 as the
“era of (eco)toxicogenomics and ecotoxicology.”
Despite the growing understanding that synthetic nanomaterials should be eval-
uated for their potential environmental hazard prior to their use in products and their
inevitable release into the environment, there is currently little data on this. The first
few studies were initiated in the 1990s, primarily evaluating the pulmonary impact
of ultrafine particles (Oberd¨rster et al. 2005b ). There was then a lag of 10 years,
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