Which properties of airborne
particles are responsible for
their toxicity?
Jozef S. Pastuszka
Chair of the Air Protection
Silesian University of Technology
What are atmospheric aerosols?
Atmospheric aerosols (or particulate matter) are solid
or liquid particles or both suspended in air with
diameters between about 0.002 µm to about
100 µm.
Inhalable particles include a fraction of aerosol
consisting of particles of a diameter below 10 µm,
which could penetrate into the airways.
These particles can cause various adverse health effects
(AHE) which can be divided into three groups:
•Toxic
(Kind and intensity of adverse health
effects is depended on the dose)
•Mutagenic and Carcinogenic
•Allergic
(Risk of cancer is depended on the dose)
(Kind and intensity is rather not depended
on the dose)
DOSE – mass or amount of toxic substance absorbed
by an organism
Every substance can be toxic
Toxicity of airborne particles depends on
the following, well-known factors:
•Dose
•Size
•Chemical composition
Ad. Dose
D > Dthreshold
Fig. 1. Scheme of the preparation of the dose-effect relationship
for a pollutant producing a threshold effect (Pastuszka, 2016).
Studies indicate associations between short- and longterm exposure to PM and increased mortality, hospital
admissions, medication use, respiratory symptoms and
reduced pulmonary function.
Inhaling fine particles involves the increase of the
mortality rate of the general population and respiratory
and cardiovascular diseases.
Fig. 4. Removing aerosol particles (Baron, 2002)
Fig. 3. Mechanisms of particle deposition in the respiratory tract.
Particles, of diameter over 10 µm are “trapped” on
the surface of the respiratory epithelium and
removed from the airways by cough, or by the cilia
movement.
Most particles of a diameter over 5 µm are retained
in the nasopharyngeal cavity and mechanically
removed from the air, before they reach the lower
part of the respiratory system.
Particles smaller than 5 µm (especially of a size
between 2.5 µm and 0.1 µm) penetrate the
respiratory system.
Ad. Chemical composition
All heavy metals in PM (examples: V, Fe, Cu, Zn, Ba, As, Cd, Co, Cr,
Mn, Ni, Pb) are considered toxic (Costa and Dreher 1997, Swaine
2000). They accumulate in body tissues (bones, kidneys, brain).
Exposure to their salts or oxides can cause acute or chronic
poisonings, tumors, diseases of the cardiovascular and nervous
systems, and of kidneys. (Lippmann 2008); some heavy metals
can weaken the immune system in humans (Goyer 1986).
According to the International Agency for Research on Cancer
(IARC), 48 PAH can be human or animal carcinogens. They are the
first air pollutants that have been identified as carcinogens. The
strength of their carcinogenicity grows with their molecular
weight.
Toxicity of airborne particles also depends on
the following factors, only partially recognized:
•Surface composition
•Shape
•Bioaccessibility
Ad. Surface composition
(1)Surface is directly accessible to biological fluids
after inhalation;
(2)Chemical transformations of particles in the
atmosphere occur on the particle surface;
Spektrometru fotoelektronów PHI 5700/660 (Physical Electronics), realizujący techniki
XPS, AES, UPS, SIMS, ISS, SEM; Zakład Fizyki Ciała Stałego, Instytut Fizyki UŚ.
http://www.zfcst.us.edu.pl/zfcst/index.htm
Promieniowanie rentgenowskie 1885
Promieniowanie elektromagnetyczne oddziałuje z materią.
Widmo promieniowania X
λ min
lampa rentgenowska
hc

E k0
widmo ciągłe
min
Fotoemisja
+
hn
0
spektrometr
EF
4f7
4f6
Natezenie
8
hn
4d10
4d9
35
30
25
20
15
10
5
0
-5
Energia wiazania (eV)
140
EB (eV)
widmo
SPEKTROSKOPIA FOTOELEKTRONÓW WZBUDZANYCH
RENTGENOWSKIMI
PROMIENIAMI
fotoelektron
Schemat powstawania fotoelektronów.
2p3/2
powłoka L
2p1/2
hn
powłoka K
2s
foton hn
1s
emisja fotoelektronu
Warunek energetyczny emisji fotoelektronów:
EK = hn - EB
gdzie: EB - energia wiązania elektronu w atomie, zależna od rodzaju atomu i jego otoczenia,
h - stała Plancka; h = 6,62 ·10-34 J·s,
n - częstotliwość promieniowania X,
EK - energia kinetyczna fotoelektronu.
C 1s
N a tę ż e nie [a .u.]
P M2.5
P M10
O 1s
Z n 2p 1/2
Mg 1s
N a 1s
F e 2p 1 /2
Z n 2p 3/2
NaK L L
S 2s
C l 2p
S 2p
N 1s
OKLL
S i 2s
S i2p
1400
1200
1000
800
600
400
200
0
E ne rg ia wią z a nia [e V ]
Zestawienie widm przeglądowych XPS aerozolu atmosferycznego PM10 i PM2.5
(Katowice, dach budynku IF, 7/8.12.2000).
określono średnie stężenia atomowe następujących pierwiastków: F, C, O, N,
Fe, S, Si, Na, Zn, I, Cu, Cl, Al, Ca, K, Mg, Pb, Ti, P i Mn.
Ad. Shape
Fig. 5. Electron micrograph of particles emitted
from the Siersza Power Station and elemental
spectra of one, selected particle (marked with
the cross). (Pastuszka et al. 2014)
Fig. 6. Micrograph of antophyllite asbestos fibers.
Picture prepared by Rożkowicz, 2007)
Fiber-like particles seem to
be more toxic than spherical
particles.
Ad. Bioaccessibility
Toxic effects of trace metals (and other
chemicals) in airborne PM are only expected if
the metals are biologically available.
To assess bioaccessibility of these metals samples
should be subjected to a batch-extraction procedure
with synthetic gastric juice.
New data – new knowledge
•There is no threshold dose for airborne particles
•Δ (AHEs) = f (ΔC)
(where ΔC = C actual – C previous)
independently on the level of C previous
Increase of concentration of PM10 by 10 µg/m3
causes the increase of upper respiratory tract
morbidity, including asthma.
•Synergistic effects
•Ultrafine particles
CONCLUSION
Although the aerosol studies have been
performing for almost 100 years there are a few
open questions and some unclear phenomena
which should be explained
- explained by you !