Potential Application of Nanoparticles as Antipathogens - Advanced Materials for Agriculture, Food and Environmental Safety - page 355

constitute a part of particulate matter (PM). Epidemiological studies have
shown that urban pollution with airborne PM deriving from combus-
tion sources such as motor vehicle and industrial emissions contributes to
respiratory and cardiovascular morbidity and mortality. h e respiratory
risks associated with air pollution have been known as the London Fog
Episode of 1952.
h e growing use of nanotechnology in high-tech industries is likely to
become another way for humans to be exposed to intentionally generate
engineered nanoparticles. Nanotechnology is also being applied in medi-
cal sciences in an attempt to achieve a personalized medicine. However, the
same properties (small size, chemical composition, structure, large surface
area and shape) which make nanoparticles so attractive in medicine, may
contribute to the toxicological proi le of nanoparticles in biological sys-
tems [97]. In fact, the smaller particles are, the more surface area they have
per unit mass; and this property makes nanoparticles very reactive in the
cellular environment [98]. h erefore, any intrinsic toxicity of the particle
surface will be enhanced. h e respiratory system, blood, central nervous
system (CNS), gastrointestinal (GI) tract and skin have been shown to be
targeted by nanoparticles [97-99].
12.15.1 RespiratorySystem
One of the most important gateways of entry and organ target for nanopar-
ticles is the respiratory system. It is well known that lungs are easily exposed
to atmospheric pollutants [100]. In this regard, combustion-derived
nanoparticles have been largely studied as a possible etiologic factor for
several adverse health ef ects, including exacerbations of airways disease as
well as deaths and hospitalization from cardiovascular disease. One of the
main mechanisms of lung injury caused by combustion-derived nanopar-
ticles is via oxidative stress leading to activation of dif erent transcription
factors with the regulation of inl ammatory protein synthesis. As nano-
technology is being applied in aerospace and computing, the release of
high amounts of nanoparticles in an enclosed environment may be of great
concern for airline crews and hardware engineers [101]. It has been found
that nanoparticles can induce increased lung toxicity compared to larger
particles with the same chemical composition at equivalent mass concen-
tration. In addition, it has also been shown that nanoparticles of dif erent
diameters can induce inl ammatory reactions in the lungs of experimental
animals [102. In fact, a signii cant correlation between the surface area of
nanoparticles and the induced inl ammation was observed via increased
oxidative stress.