Agriculture Reference
In-Depth Information
engineered nanomaterials (ENMs), defined as man-made materials with their size
less than 100 nm in at least two dimensions (Bradford et al.
2009
), have been
developed and incorporated into fertilizers, nanosensors, and pathogen-combating
formulae (Knot et al.
2012
). The broad potential applications of ENMs are derived
from several appealing features of ENMs: their very small size and large specific
surface area, manipulative surface chemistry, and generation of reactive oxygen
species. Even though the size and properties associated with it (e.g., large specific
surface area) are the predominant parameters distinguishing ENMs from other
man-made materials, other physicochemical properties of ENMs such as their
composition, shape, surface coating, and charge also heavily affect their environ-
mental stability and biological compatibility. Therefore, while ENMs is often
applied in the literature as a general term, it should be understood that ENMs
contain a diverse group of materials within unique physicochemical properties and
consequently highly different environmental impacts.
While these diverse features lend ENMs more versatile applications, there have
also been concerns about their environmental health and safety impacts. In terms of
the interactions of ENMs with plants, numerous previous researches have demon-
strated that ENMs can affect plant growth, which plays important ecological and
economical roles. There also have been reports showing that ENMs could accumu-
late in plant tissues, providing a potential pathway for the exposure of ENMs to
humans through food consumption. These interactions complicate the beneficial
applications of ENMs as fertilizers, nanosensors, and other agriculture-enhancing
products and have important implications for food safety. Therefore, the under-
standing of the interactions of ENMs with agricultural crops is of critical impor-
tance. This chapter will start with a brief introduction on ENMs, followed by a
discussion on their physiological and genetic effects on agricultural crops and their
uptake and accumulation by agricultural crops. The chapter will then continue to
examine the alteration on the fate and transport of coexisting environmental
chemicals by ENMs in agricultural systems. The chapter will be closed with a
future perspective section highlighting important future research needs on the
interactions of ENMs with agricultural crops and a short conclusion. The primary
objective of this chapter is to present a comprehensive review on the interactions of
the four most commonly encountered ENMs with agricultural crops, summarizing
their potential toxicity to plants and accumulation in plant tissues in the hope to
draw insights on the possible relationship between their fate and impact in agricul-
tural systems and their unique properties. The second objective is to evaluate the
interactions of ENMs with other co-contaminants in agricultural systems to obtain a
more comprehensive understanding on the impacts of ENMs in agricultural
systems.
