AhR-mediated effects of six size-fractions of PM10
from urban and country site
Jiri Novaka, Anita Ersekovaa, John Paul Giesyc,d,e and Jana Klanovaa
Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk
University, Kamenice 3, Brno, Czech Republic
b Department of Biomedical Veterinary Science and Toxicology Centre, Univ. of Saskatchewan, Canada
c Zoology Department and Center for Integrative Toxicology, Michigan State University, East Lansing, USA
d Biology and Chemistry Department, City University of Hong Kong, Kowloon, Hong Kong, SAR, China
e School of Biological Sciences, University of Hong Kong, Hong Kong, SAR, China
a
Contact: novakj@recetox.muni.cz
Introduction
Introduction
Hypothesis
Air pollution
 Pollutants from various sources are directly or
indirectly released to the atmosphere.
 These compounds are present in gaseous form
and/or associated with air particles (PM).
 The air pollution was described to cause many
types of adverse health effects e.g. lung cancer,
respiratory diseases, atherosclerosis or genotoxic
effects [1].
 Is there a relationship between AhR-mediated activity and size of inhalable particulte
matter (PM)?
 Are there differences in spring and summer patterns of AhR-mediated activities of ambient
air samples?
 Is there a difference between urban and country site pattern of AhR-mediated activity?
Fig. 1Particle
deposition as a
function of
particle diameter
in respiratory tract
parts
(Source: Task Group
on Lung Dynamics
(1996). Health
Physics. 12: 173.)
Fig. 2 Cascade
impactorparticles with
enough inertia
impact on the
collection plate.
Smaller particles
proceed to the
other stage of
impactor
Material and methods
Samples
air samples- four month sampling during spring and
winter season 2010-1by high volume cascade
impactor catching air particulates with diameter 7.2–
10; 3–7.2; 1.5–3; 0.95–1.5; 0.45–0.95; < 0.45 µm
(A-F) and polyurethane foam filters catching gas
fraction (G).
Sampling sites
urban: busy crossroad in Brno City (Czech Republic)main pollution source: traffic, local heating
country: village eight kilometeres from Brno
main pollution sources: local heating, agriculture
AhR-mediated effect
H4IIE-luc (rat hepatocarcinoma) stably transfected
with luciferase gene under control of AhR used for
analysis of dioxin-like activity of air extracts and
calculation of dioxin toxic equivalents (bioTEQ,
Fig.3). Dioxin-like activity in the samples calculated
using equi-effective approach described previously
[3].
spring
country site
urban site
10000
bioTEQ (fg/m )
100000
10000
country site
urban site
3
1000
100
10
1000
100
sample fractions
G
F
E
D
C
B
G
F
E
D
C
B
A
10
A
bioTEQ (fg/m3)
Specific biological effects of the air contaminants
 Some studies have indicated that the air pollutants
could act also as endocrine disruptors [2]
 AhR-mediated activity is a marker of compounds
associated with immunity defects, carcinogenesis
and at is partly with endocrine disruption [2]
 Association of air pollutants with specific effects
with different sized inhalable fractions of air
particulates has not been thoroughly described
Size fractions
• Only particles smaller than 10µm can enter
respiratory tract
• The lower the diameter –the greater toxic effects
(higher penetration into lungs, higher specific
surface area of particles)
winter
sample fractions
Fig. 3 AhR-mediated effects produced by air sample fractions expressed in equivalent of TCDD (fg/m3) at
both localities in winter and spring, aerodynamic diameter of particles in PM fractions 7.2-10 µm (A); 37.2 µm (B); 1.5-3 µm (C); 0.95-1.5 µm (D); 0.45-0.95 µm (E) and < 0.45µm (F); gas phase pollutants (G)
(mean from at least three experiments ±SEM); fractions A and G from country site in spring did not
produce effect high enough for quantification
Results and discussion
 At both sites, there is a clear trend of increasing AhR-mediated effects with decreasing aerodynamic
diameter of atmospheric particles
 Highest effects were associated with fractions that penetrate the deepest into lungs (Fig.1)
 Activity of gas phase fraction of organic compounds (fraction G) is less pronounced but it is not
negligible
 Winter samples were significantly more potent at both sites than the spring samples. This is caused by
lower photodegradation and especially by higher emisions during the cold season by local heating
 Country locality seems to the more polluted in both seasons. This is probably caused by higher usage of
less environment-friendly local heating fuels (coal, waste) than at the urban site (natural gas). Intensive
traffic at urban site did not turn this trend
 In spring, urban site samples contained higher levels of active compounds in coarser fractions (A,B)
than the country site samples. This might be caused indirectly by traffic at urban site. The coarser PM
fractions could be kept in the air for longer time by air whirling
Conclusion
 The greatest AhR-mediated effects were produced by the finest particle size fractions that
are potentially the most dangerous (Fig. 1, 3)
 Significant part of active compounds was present in the gas phase at both sites (fraction G)
 Higher effects were observed in samples from the winter sampling period
 The country site samples were more potent in most fractions in activation of AhR.
Substantial portion of active compounds is therefore from local sources
Acknowledgements/References
This research was supported by the projects GACR P503/10/P249 and CETOCOEN
(CZ.1.05/2.1.00/01.0001)
1. Kampa, M. and E. Castanas (2008). "Human health effects of air pollution." Environmental Pollution
151(2): 362-367.
2. Novak, J., V. Jalova, et al. (2009). "Pollutants in particulate and gaseous fractions of ambient air
interfere with multiple signaling pathways in vitro." Environment International 35(1): 43-49.
3. Villeneuve, D.L., A.L. Blankenship, and J.P. Giesy, Derivation and application of relative potency
estimates based on in vitro bioassay results. Environmental Toxicology and Chemistry, 2000. 19(11): p.
2835-2843.