Chemistry Reference
In-Depth Information
especially for the indoor environments. Their ambient concentrations may increase
in future due to widespread use of nanotechnology integrated products. Evaluation
of their sources and probable impacts on air quality and human health are briefly
discussed in the following section. Respiratory deposition doses received by the
public exposed to roadside PNCs in numerous European locations are then
estimated. These were found to be in the 1.17-7.56
10
10
h
1
range over the
studied roadside European locations. The following section discusses the potential
framework for airborne nanoparticle regulations in Europe and, in addition, the
existing control measures to limit nanoparticle emissions at source. The chapter
finally concludes with a synthesis of the topic areas covered and highlights impor-
tant areas for further work.
Keywords Aerosol number and size distributions, Engineered nanoparticles,
European environment, Exposure-response doses, Ultrafine particles
Contents
1 Introduction .................................................................................. 340
2 State-of-the-Art Summary of Recent Review Articles . . .................................. 341
3 Physico-Chemical Characteristics of Airborne Nanoparticles ............................. 343
4 Origin of Atmospheric Nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
4.1 Natural Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
4.2 Anthropogenic Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
5 Airborne Nanoparticle Concentrations in European Cities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
6 Exposure Assessment: Respiratory Deposition Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
7 Regulatory Measures for Atmospheric Nanoparticles ..................................... 356
8 Synthesis and Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
1
Introduction
Atmospheric particles in the nano-size range contribute significantly to particle
number concentrations (PNCs). These also have the potential to adversely affect
human health due to their ability for deep penetration into the lungs [
1
] and beyond.
Hence, this chapter only focuses on particle “numbers.” In what follows, the terms
“ultrafine particles” and “nanoparticles” are used interchangeably according to the
context for representing the “total PNCs.” In the recent past, there has been a
significant increase in number of studies related to characterisation, monitoring,
modelling and human exposure assessment of airborne nanoparticles, though this
progress has not been sufficient to inform any regulatory framework or to establish
ambient air quality standards [
2
]. There still remain a number of inconclusive
results on various aspects such as exposure-response relationships and standardised
sampling methodology [
3
]. This is further complicated by the lack of information
on physico-chemical characteristics and behaviour of emerging sources such as
biofuel-derived nanoparticles or
synthesised, manufactured or
engineered
nanomaterials or nanoparticles; hereafter referred to as ENPs [
4
,
5
].
