13

Polycyclic Aromatic Hydrocarbons from
Vegetation Burning and Health Effects
Kazuichi HAYAKAWA
Institute of Nature and Environmental Technology, Kanazawa University
Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan
E-mail: hayakawa@p.kanazawa-u.ac.jp

Abstract
Air pollution now causes several million deaths each year. Among air pollutants, polycyclic aromatichydrocarbons (PAHs) and their derivatives, such as nitro-, hydroxy- and quinoid PAHs attract much attention.
These pollutants are emitted through burning processes of fossil fuels and vegetation, and exist in gas andparticle phases in the air. Despite their strong adverse health effects, including lung cancer, asthma andendocrine disruption, their outdoor and indoor air pollution levels have not been reduced quickly worldwide.
Recently, biomass has become popular as a renewable energy source that does not increase the atmosphericconcentration of global carbon dioxide, a greenhouse gas implicated in global warming. On the other hand,
there are still many areas in developing countries where slash-and-burn farming is practiced, and forest fires
have been increasing rapidly worldwide. Therefore, sufficient attention is needed to the health effects of PAHs
and related compounds generated from these sources. The aim of this report is to describe the emission anddistribution of PAHs and their derivatives in outdoor and indoor air and their health effects, focusing on
vegetation fires.
Key words: health effect, nitropolycyclic aromatic hydrocarbon, oxygenated polycyclic aromatic hydrocarbon,
polycyclic aromatic hydrocarbon, vegetation burning

1. Introduction
Air pollution increases mortality and morbidity. The
World Health Organization (WHO) has reported that the
combined effects of ambient air pollution and household
air pollution are associated with 6.7 million premature
deaths annually (WHO, 2018). World coal and oil
consumption has steadily increased since the industrial
revolution. The WHO has reported recently that air
pollution is very serious in the Western Pacific region(WHO, 2023). Fossil fuels such as coal and petroleum
account for a large proportion of the world’s primaryenergy consumption. In this region, biomass is also an
important fuel both indoors and outdoors. Moreover,slash-and-burn farming, forest fires, habits such as
smoking, and incense burning also increase personal
exposure to air pollutants.
Among air pollutants, polycyclic aromatichydrocarbons (PAHs) and their derivatives, such as
nitrated PAHs (NPAHs) and oxygenated PAHs (OPAHs),
are known to be generated by incomplete combustion oforganic substances and to induce various adverse health
Global Environmental Research
27/2023 13-20
printed in Japaneffects, including carcinogenicity and mutagenicity. PAHs
contain two or more 4- to 6-carbon fused rings, of which
the benzene-ring structure is the most common. This
report focuses on PAHs and their derivatives emitted fromvegetation fires and describes adverse health effects
resulting from human exposure.

2. PAHs and Their Derivatives
2.1 PAHs, NPAHs, QPAHs and OHPAHs
Many kinds of PAHs and their derivatives, such as
NPAHs, hydroxylated PAHs (OHPAHs), quinoid PAHs
(QPAHs) and halogenated PAHs (XPAHs), are produced
through incomplete combustion of organic materials andsecondary atmospheric reactions. In this report, theOHPAHs and QPAHs are classed among the oxy-PAHs(OPAHs). During combustion processes, particulatematter (PM), i.e., soot, is also formed. In the air, two- andthree-aromatic ring PAHs occur mainly in the gas phase,five- and higher-ring PAHs are bound to particles (particle
phase), and four-ring PAHs are found in both phases. PAH
derivatives also exist in both phases in a similar manner to©2023 AIRIES14

K. HAYAKAWA

that of PAHs depending on ring numbers. In this report,
abbreviations are used for major PAHs and theirderivatives. Please refer to the list of abbreviations at theend of this report. Their chemical structures are shown in
Fig. 1.
2.2 Distribution in Ambient Air
PAHs and their derivatives are ubiquitous in bothindoor and outdoor air. As described above, lowermolecular-weight PAHs exist in gaseous form. Likewise,
higher-molecular-weight PAHs exist mainly as fine PMwith an aerodynamic diameter of less than or equal to anominal 2.5 µm (PM2.5). The distribution of theirderivatives has similar tendencies. Fig. 2 showsconcentrations of major PM2.5-bound PAHs, NPAHs,
OHPAHs and QPAHs measured in urban air in Kanazawa,
Japan. Although the concentration levels of the derivative
groups differ greatly, the concentration order shows thesame trend between urban and suburban air and between

vehicular and other combustion emissions (Hayakawa
et al., 2020]. As can be seen in Fig. 2, the concentrationsof total PAHs (ΣPAH), NPAHs (ΣNPAH), OHPAHs(ΣOHPAH), and QPAHs (ΣNOPAH) in Kanazawa City
were 1000 pg m-3, 9.6 pg m-3, 75 pg m-3 and 420 pg m-3,
respectively, with [ΣPAH] > [ΣQPAH] > [ΣOHPAH] >[ΣNPAH] in decreasing order. Among these compounds,
pyrene (Pyr), benz[a]anthracene (BaA) and benz[a]pyrene(BaP) are the PAHs whose derivatives were commonly
detected in the NPAHs, OHPAHs and QPAHs. For
example, three isomers were respectively detected as
pyrene-quinones (PyrQs). The concentration order of Pyrderivatives, quinoid pyrenes (QPyrs), hydroxypyrenes(OHPyrs) and nitropyrenes (NPs), were [Pyr] > [QPyrs] >[OHPyrs] > [NPs]. The derivatives of BaA and BaP also
showed the same decreasing order described above. These
results suggest that the order of concentrations of PAHs
and their derivatives mainly depends on how easily the
PAHs are derived in the combustion of organic matter.

Abbreviations, see list of abbreviation.
Fig. 1

Chemical structures of PAHs, NPAHs, OHPAHs and QPAHs.

Polycyclic Aromatic Hydrocarbons from Vegetation Burning and Health Effects

Fig. 2

15

Atmospheric PM2.5-bound PAHs, NPAHs, OHPAHs and QPAHs.
PM2.5 samples were collected for one week in the winter of 2018.

Fig. 3

Metabolic activation of BaP.

3. Metabolism of PAHs and Health Effects
3.1 Metabolic Activation
In accordance with the most accepted metabolic
activation of PAHs (Straif et al., 2013), Fig. 3 gives an
overview of the metabolic activation of PAHs in animals
and microorganisms, using benzo[a]pyrene (BaP) as arepresentative PAH (Hayakawa, 2016). BaP can bind to
the aryl hydrocarbon receptor (AhR) that induces thecytochrome P450 (CYP) family (e.g., CYP1A1, CYP1A2,
CYP1B1), which forms epoxides, quinones and phenolsof BaP. The first metabolic activation pathway involves
the formation of BaP-7,8-diol-,9,10-epoxide, which leads
to DNA adduct formation, exhibiting carcinogenicity(green route). The second metabolic pathway involves theformation of OHPAHs in the presence of CYP. Several
OHPAHs have been found to bind to estrogen receptors(ERs) or inhibit estrogens from binding to ERs. A
chemical structure-biological activity relationship isconsidered the mechanism (red route) (Hayakawa et al.,2007). As a result, the number of papers on therelationship between PAHs and endocrine disruption has
been increasing (Cathey et al., 2020). The third metabolic
pathway involves the formation of QPAHs. Several
QPAHs, such as 9,10-phenanthrenequinone (9,10-PQ),
overproduce reactive oxygen species (ROS) through aredox cycle (blue route). On the other hand, PAHs are
nitrated to NPAHs during combustion processes and via
secondary atmospheric reactions. In microorganisms,
NPAHs are metabolized to nitroso-, hydroxyamino-, andfinally, amino-derivatives of PAHs. In this pathway,hydroxyamino PAHs cause DNA adduct formation. Thisis known to be an indirect-acting mutagenic pathway of
NPAHs (brown route) (Hayakawa, 2016).

16

K. HAYAKAWA

3.2 Carcinogenicity and Adverse Health Effects
Epidemiological and animal experimental evidence
on the health effects of air pollution has been growing andevolving. The International Agency for research on
Cancer (IARC) has classified more than sixty PAHs andrelated compounds into four classes, carcinogenic tohumans (Group 1), probably carcinogenic to humans(Group 2A), possibly carcinogenic to humans (Group 2B)and not classifiable as to their carcinogenicity to humans(Group 3). Among them, BaP is in Group 1. It is
important that this classification is based on the evidenceof carcinogenicity to humans, but does not dependon the strength of the carcinogenicity. Four
PAHs, cyclopenta[cd]pyrene, dibenz[a,h]anthracene,
dibenzo[a,l]pyrene, dibenz[a,j]acridine and one NPAH,
1-NP, are in Group 2A. Fifteen PAHs and hetero
derivatives, such as Nap, benz[j]aceanthrylene, BaA, BbF,
benzo[j]fluoranthene,
BkF,
benzo[c]phenanthrene,Chr,5-methylchrysene,
dibenzo[a,h]pyrene,
dibenzo[a,i]pyrene, IDP, benzofuran, dibenz[c,h]acridine
and dibenz[a,h]acridine and five NPAHs, such as 5-NAc,
2-NF, 4-NP, 1,6- and 1,8-DNPs are in Group 2B. The
other PAHs and NPAHs such as Fle, Pyr, 2-NP and
6-NBaP, are in Group 3, because of their limited orinadequate experimental evidence (Table 1). The IARC
also classified PAH-containing materials, such as shaleoils, coal-tar distillates, coal-tar pitch, coke, coalgasification products, indoor emissions from household
combustion of coal, iron and steel founding products(occupational exposure), engine exhaust, diesel, outdoor
air pollution, PM in outdoor pollution, soot (as found in
Table 1

occupational exposure of chimney sweeps), tobaccosmoke and second-hand tobacco smoke in Group 1 (IARC,
2021). It is thought that PAHs, NPAHs or OPAHs, which
are contained in those materials, might contribute as
causative agents to oxidative DNA damage.
Epidemiological studies on adverse effects of thesepollutants on lung function have been reported (Brucker
et al., 2014; Mordukhovichi et al., 2016; Wang et al,2016).
PAHs are oxidized by ozone or nitrogen dioxide to
produce QPAHs, OHPAHs or NPAHs in the atmosphere.
They are adsorbed in the bronchi and alveoli to induce theproduction of ROS by the above metabolic pathway (Pitts
et al., 1980; Pitts, 1983; Yoshikawa et al., 1985; Kumagai
et al., 1997 and 2012; Hayakawa et al., 2007). Among
PAHQs, ortho-QPAHs overproduce ROS and thereby
significantly decrease cell viability, whereas para-QPAHs
do not (Motoyama et al., 2009). ROS causes airway
inflammation and exacerbation of asthma and allergies(Al-Daghri et. al., 2013; Anyenda et al., 2016; Zhao,
2022; Hara et al., 2022). Recently, the number of reports
on non-genotoxic effects of OPAHs has been increasing:
QPAHs and/or OHPAHs activate the aryl hydrocarbon
receptor, additional nuclear receptors and intracellularsignaling pathways. These facts suggest the possibility
that OPAHs play an adverse role in the development,
metabolism and growth of humans and animals and that
more attention needs to be paid to the toxicities of PAH
metabolites (Vondráček and Machala, 2021).

Carcinogenicity classification of PAHs and their derivatives.

(not classifiable
as to theircarcinogenicity
to humans,
because oflimited orinadequate
experimental
evidence)

Polycyclic Aromatic Hydrocarbons from Vegetation Burning and Health Effects

4. Emission Sources
4.1 Sources of PAHs and NPAHs
There are many kinds of emission sources for PAHs
and their derivatives: vehicles, ships, aircraft, cokeproduction, industries such as iron-steel, aluminum andothers, and agricultural machines that use fossil fuels.
Petroleum cracking plants, gas stations, forest fires(wildfires) and open burning of crop residues constitutemajor outdoor sources. On the other hand, the combustionof coal, oil and gas, and the use of firewood and othervegetation fires in heating and cooking constitute indoor
sources. Smoking is also a source, especially indoors. Of
these sources, the contributions of residential/commercial
biomass burning and open-field vegetation fires(agricultural waste burning, deforestation and wildfires)
accounted for 60.5% and 13.6%, respectively, of the 16
global atmospheric PAHs in 2007, which were muchlarger than that of vehicles (12.8%) (Shen et. al., 2013).
However, a survey of rural areas in China reported thatthe contribution of vegetation fires (15.9%) was smaller
than the contribution of vehicles (32.7%) in 2020 (Liet. al., 2023). Thus, there have been large differences
between reports in the contribution of vegetation fires toatmospheric PAHs.
4.2 Chemical Characteristics of Vegetation Fires
Several review reports have been published for PAHs
emitted from biomass burning (Vicente and Alves, 2018;
Zhang et al., 2022). The compositions of the PAHs andtheir derivatives were not very strongly affected by fueltype (Zhang et al., 2022), but with increasing combustion
temperature, the fraction of higher molecular PAHs
became larger than that of lower molecular PAHs
(McGrath et al., 2003; Iinuma et al., 2007). On the other
hand, the amounts of NPAHs emitted differed greatly
depending on combustion temperature. Combustion
temperatures in vehicle engines, coal stoves and wood

Fig. 417

stoves were 2,700 − 3,000°C, 1,100 − 1,200°C and 500 −
600°C, respectively (Hayakawa, 2016). Fig. 4 compares
the concentrations of PAHs and NPAHs in PM emitted bydiesel vehicles (DEP), coal burning (CEP) and woodburning (WEP). WEP showed the highest concentration of
PAHs, followed by CEP. DEP showed the lowest
concentration. On the other hand, DEP showed the highest
concentration of NPAHs, followed by CEP. WEP showed
the lowest concentration.
The above result is explained as follows: The
formation of NOx depends on combustion temperatureand the formation of NPAHs from corresponding PAHs in
the presence of NOx also depends on combustion
temperature. Increased combustion temperature results inincreased yield of NPAHs. The concentration ratio of
NPAHs to their parent PAHs (= [NPAH]/[PAH]) increases
depending on elevation of combustion temperature,suggesting an effective index for identifying the
combustion source. Based on this principle, a new method
using 1-NP and Pyr as monitoring markers has beendeveloped for analyzing source contributions (Hayakawa
et al., 2020 and 2021). The [1-NP]/[Pyr] ratio of PM fromvegetation fires is more than two orders of magnitude
smaller than that of PM from vehicles.
4.3 Vegetation Fires Globally
PAHs and their derivatives attract great attention
because of their adverse health effects—not only
carcinogenicity but also mutagenicity, endocrine
disruption activity and reactive oxygen production activity.
There have been many reports on the effects of
combustion sources on organic and inorganic pollutants
formed through biomass combustion. Among them, thisreport focuses on the combustion of biomass. Globally,
the post-harvest burning of crops and forest fires results inwidespread air pollution (Chuesaard et al., 2014; Phamet al., 2019; Tomaz et al., 2017; de Oliveira Galvao et al.,2018), and domestic heating and cooking using biomass

Concentrations of ΣPAH and ΣNPAH in PMs from different sources.

PM sources: WEP=wood burning; CEP=coal burning; DEP=diesel-engine vehicles.
ΣPAH = FR + Pyr + BaA + Chr + BbF + BkF + BaP + BgPe + IDP. ΣNPAH = 1,3-DNP + 1,6-DNP + 1,8-DNP + 1-NP.

18

K. HAYAKAWA

fuels causes indoor air pollution (Kitanovski et al., 2020;
Chen et al., 2017; Orakij, 2017). These are summarized inTable 2. PAHs, OHPAHs and QPAHs and NPAHs were
found characteristic. As a marker of vegetation fires,levoglucosan was determined. The decreasing
Table 2concentration order of [PAHs] > [QPAHs] > [OPAHs] >[NPAHs] and the smaller [1-NP]/[[Pyr] concentration
ratio were often observed in air carrying emissions fromvegetation fires.

Environmental Studies on PAHs and OPAHs from vegetation fires.
SampleSourceAnalyzed
CompoundCharacteristics

Ref.

1. ΣPAH (4.1 ng m-3) and ΣNPAH (523 pg m-3) in dry season > ΣPAH
(0.70 ng m-3) and ΣNPAH (40.6 pg m-3) in wet season
2. The larger [BaP]/[BgPe] in dry season suggested vegetation fire andthe larger [1-NP]/[Pyr] in wet season suggested vehicles.
1. ΣPAH (4488 ng m-3) and ΣNPAH (288 µg m-3) in burning period >ΣPAH (14 ng m-3) and ΣNPAH(25 µg m-3) in background period
2. ΣPAH > ΣNPAH
3. Secondary formation of 2-NF and 2-NP

Chuesaard
et al., 2014

Outdoor
SPM in Chiang Mai,
Thailand, in dry and wet
seasons

10PAHs,
19NPAHs

PM in suburban area ofHanoi, Vietnam

Forest fireandagricultural
burning
Rice straw
open burning

PM10- in Grenoble, Francein winter

Residential
heating

21PAHs,32NPAHs,
27OPAHs,
levoglucosan

1. ΣPAH > ΣOPAH > ΣNPAH
2. 2-Methylnaphthalene (48.6 ng m-3), 2-methylfluoranthene (0.4 ngm-3), 1-NP (46 pg m-3) and levoglucosan (2963 ng m-3) in winterwere higher than those in summer.
3. Secondary formation of 2-NF and 2-NPTomazet al., 2017

PM10 in Amazon, Brazil,
in dry and wet seasons

Forest fire

11NPAHs,
4OPAHs

1. ΣPAH > ΣNPAH
2. 2-Methylanthraquinon (260 pg m-3) and 1-NP (0.125 ng m-3) inintense vegetation fire period were higher than
2-methylanthraquinon (70 ng m-3) and 1-NP(70 pg m-3) in moderate
vegetation fire period.

de Oliveira
Galvaoet al., 2018

SPM (6 fractions less than
10 µm) in Thessaloniki,
Greece, in winterResidential
heating

11NPAHs,
7OPAHs

1. ΣQPAH (47–1636 and 858–4306 pg m-3) > ΣNPAH (≤ 90 and
76–578 pg m-3)
2. Distribution dependent on PM size.

Kitanovski
et al., 2020

PM (5 fractions) in rural
areas, China

Cooking

10PAHs,4OPAHs

1. ΣPAH > ΣNPAH
2. 1-Nitronaphthale: Kitchen (0.80 ng m-3) and living room
(0.26 ng m-3) > outdoor (0.13 ng m-3)
3. Benzanthrone: Kitchen (106 ng m-3) > living room (21 ng m-3)
4. Biomass > LPG

Chen et al.,2017

PM2.5, in Thailand

Cooking
Biomass (6types) andcoal (4 types)
burning

1.
2.
3.
1.

ΣPAH (9980 ng m-3) > ΣNPAH (18700 pg m-3)
Cooking period > noncooking period
The carcinogenic risks exceeded the WHO guideline values.
ΣPAH (32.3–279 mg kg-1) > ΣOPAH (5.18–42.5 mg kg-1) > ΣNPAH(37.4–343 µg kg-1).
2. Compositions of PAHs and derivatives were not affected by fueltype.

Orakijet al., 2017

PM2.5 from kangs andstoves under heating
scenarios

10PAHs,11OPAHs,
levoglucosan
22PAHs, 7alkyl
PAHs,
12NPAHs
10OPAHs

9PAHs,
4NPAHsPham
et al., 2019

IndoorZhang
et al., 2021

Abbreviations of PAHs and Their Derivatives
PAHs

NPAHs

OHPAHs

PAHQs

polycyclic aromatic hydrocarbons (PAHs), naphthalene (Nap), acenaphthene (Ace), fluorene (Fle),phenanthrene (Phe), anthracene (Ant), Fluoranthene (Flu), pyrene (Pyr), benz[a]anthracene(BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene(BaP), dibenz[a,h]anthracene (DBA), benzo[ghi]perylene (BgPe), indeno[1,2,3-cd]pyrene (IDP)
nitrated PAHs (NPAHs), 1-, 2-, 4-nitropyrene (1-, 2-, 4-NP), 1,3-, 1,6-, 1,8-dinitropyrene (1,3-,
1,6-, 1,8-DNP), 1-, 10-nitrobenzanthrone (1-, 10-NBA), 2-nitrofluorene (2-NF), 2-,9-nitroanthracene (2-, 9-NA), 5-nitroacenaphthene (5-NAc), 4-, 9-nitrophenanthrene (2-, 9-NPh),
3-nitrofluoranthene (3-NFL), 7-nitrobenz[a]anthracene (7-NBaA), 2-nitrotriphenylene (2-NTP),
6-nitrochrysene (6-NC), 6-nitrobenzo[a]pyrene (6-NBaP), 1-, 3-nitroperylene (1-, 3-NPer)halogenated PAHs (XPAHs), hydroxylated PAHs (OHPAHs), 1-, 2-hydroxynaphthalene (1-,
2-OHNap), 1-, 2-, 3-hydroxyfluoranthene (1-, 2-, 3-OHFlu), 1-, 2-, 3-, 9-hydroxyphenanthrene(1-, 2-, 3-, 9-OHPhe), 1-, 2-, 3-hydroxypyrene (1-, 2-, 3-OHPyr), 3-hydroxybenzo[a]pyrene(3-OHBaP), 6-hydroxychrysene (6-OHChr), 3-hydroxybenzo[a]pyrene (3-OHBaP)
1,4-benzoquinone (BQ), 2-methyl-1,4-benzoquinone (2-MBQ), 2,5- and2,6-dimethylbenzoquinones (2,5- and 2,6-DMBQ), tetramethylbenzoquinone (TMBQ), 1,2- and
1,4-naphtoquinones (1,2- and 1,4-NQ), 2-methyl-1,4-naphthoquinone (2-MNQ),
acenaphthoquinone (AceNQ), 1,4- and 9,10-phenanthrenequinones (1,4- and 9,10-PQ), 1,4- and9,10-anthraquinones (1,4- and 9,10-AQ), 1,6-, 1,8- and 4,5-pyrenequinones (1,6-,1,8- and
4,5-PyrQ), fluoranthene-2,3-quinone (2,3- FluQ), aceanthraquinone (AceAQ), 1,4- and5,6-chrysenequinones (1,4- and 5,6-CQ), 5,12-naphthacenequinone (5,12-NapQ),
benzo[c]phenanthrene-5,6-quinone (5,6-BcPQ), 7,12-benzanthraquinone (7,12-BAQ),
benzo[e]pyrene-4,5-quinone (4,5- BePQ), benzo[a]pyrene-1,6-, -3,6-, -4,5-, -6,12- and-11,12-quinones (1,6-, -3,6-, -4,5-, -6,12- and -11,12- BaPQ),
dibenzo[a,j]anthracene-7,14-quinone (7,14-DBajAQ) and dibenzo[a,h]anthracene-5,6-quinone(5,6-DBahAQ)

Polycyclic Aromatic Hydrocarbons from Vegetation Burning and Health Effects

5. Conclusion
5.1 Organic material that comes from plants and animals
is converted not only to solid fuels but also to gas andliquid fuels. Biomass is attracting attention as arenewable energy source, because organic materials
in biomass can be regenerated in a short time period
from carbon dioxide, a global warming gas, in theatmosphere.
5.2 As mentioned in this report, combustion of thisbiomass produces various hazardous chemicals,
including PAHs and their derivatives. It will beessential to develop technology to prevent theseharmful substances from being released into the air,both outdoors and indoors.
5.3 On the other hand, although restrictions on
incineration of post-harvest crop residues have been
implemented in developed countries, it is stillpracticed in developing countries. In addition, forest
fires occur frequently around the world, and thenumber of such fires has been increasing due toglobal warming. These also raise the atmosphericconcentration of PAHs and their derivatives overwide areas—a big problem.
References
Al-Daghri, N.M., Alokail, M.S., Abd-Alrahman, S.H., Draz, H.M.,
Yakout, S.M. and Clerici, M. (2013) Polycyclic aromatichydrocarbon exposure and pediatric asthma in children: a casecontrol study. Environmental Health, 12: 1. https://doi.org/
10.1186/ 1476-069X-12-1
Anyenda, E.O., Higashi, T., Kambayashi, Y., Nguyen, T.T.T.,
Michigami, Y., Fujimura, M., Hara, J., Tsujiguchi, H., Kitaoka,
M., Asakura, H., Hori, D., Yamada, Y., Hayashi, K., Hayakawa,
K. and Nakamura, H. (2016) Associations of cough prevalencewith ambient polycyclic aromatic hydrocarbons, nitrogen andsulphur dioxide: A longitudinal study. International Journal ofEnvironmental Research and Public Health, 13, 800.
https://doi.org/10.3390/ijerph13080800
Brucker, N., Charão, M.F., Moro, A.M., Ferrari, P., Bubols, G.,
Sauer, E., Fracasso, R., Durgante, J., Thiesen, F.V., Duarte, M.M.,
Gioda, A., Castro, I. and Garcia, S.C. (2014) Atherosclerotic
process in taxi drivers occupationally exposed to air pollution
and co-morbidities. Environmental Research, 131: 31–38.
https://doi.org/ 10.1016/j.envres.2014.02.012
Cathey, A.L., Watkins, D.J., Rosario, Z.Y., Vélez Vega, C.M., Loch,
Caruso, R., Alshawabkeh, A.N., Cordero, J.F. and Meeker, J. D.
(2020) Polycyclic aromatic hydrocarbon exposure results inaltered CRH, reproductive, and thyroid hormone concentrations
during human pregnancy. Science of The Total Environment,
749: 141581. https://doi.org/10.1016/j.scitotenv.2020.141581
Chen, Y., Du, W., Shen, G., Zhuo, S., Zhu, X., Shen, H., Huang, Y.,
Su, S., Lin, N., Pei, L., Zheng, X., Wu, J., Duan, Y., Wang, X.,
Liu, W., Wong, M. and Tao, S. (2017) Household air pollution
and personal exposure to nitrated and oxygenated polycyclicaromatics (PAHs) in rural households: Influence of householdcooking energies. Indoor Air, 27: 169–178. https://doi.org/
10.1111/ina.12300
Chuesaard, T., ThanChetiyanukornkul, T., Kameda, T., Hayakawa,

19

K. and Toriba, A. (2014) Influence of biomass burning on thelevels of atmospheric polycyclic aromatic hydrocarbons and theirnitro derivatives in Chiang Mai, Thailand, Aerosol and Air
Quality Research, 14: 1247–1257. https://doi.org/10.4209/aaqr.
2013.05.0161
de Oliveira Galvao., de Oliveira Alves, N., Ferreira, P., Caumo, S.,
de Castro Vasconcellos, P., Artaxo, P., de Souza Hacon, S.,
Roubicek, D. and de Medeiros, S. (2018) Biomass burning
particles in the Brazilian Amazon region: Mutagenic effects ofnitro and oxy-PAHs and assessment of health risks.
Environmental Pollution, 233: 960–970. https://doi.org/10.1016/
j.envpol.2017. 09.068
Hara, A., Odajima, H., Matsuzaki, H., Fujimura, M., Toma, T.,
Wada, T., Ohkura, N., Pham, K.O., Suzuki, K., Tsujiguchi, H.,
Takami, A., Hayakawa, K. and Nakamura, H. (2022) Association
between cough and ambient polycyclic aromatic hydrocarbons inpatients with chronic cough: an observational study in two
regions of Japan. Applied Sciences, 12: 12505. https://doi.org/
10.3390/app122412505
Hayakawa, K., Onoda, Y., Tachikawa, C., Hosoi, S., Yoshita, M.,
Chung, S. W., Kizu, R., Toriba, A., Kameda, T. and Tang, N.
(2007) Estrogenic/antiestrogenic activities of polycyclic aromatichydrocarbons and their monohydroxylated derivatives by yeast
two-hybrid assay. Journal of Health Science, 53: 562–570.
https://doi.org/ 10.1248/jhs.53.562
Hayakawa, K. (2016) Review: Environmental behaviors andtoxicities of polycyclic aromatic hydrocarbons andnitropolycyclic aromatic hydrocarbons. Chemical andPharmaceutical Bulletin, 64: 83–94. https://doi.org/10.1248/
cpb.c15-00801
Hayakawa, K., Tang, N., Toriba, A. and Nagato, E.G. (2020)
Calculating sources of combustion-derived particulates using
1-nitropyrene and pyrene as markers. Environmental Pollution,
265
Part
B:
114730.
https://doi.org/10.1016/j.envpol.
2020.114730
Hayakawa, K., Tang, N., Matsuki, A., Inomata, Y., Toriba,
A. and Nagato, E.G. (2021) Calculating source contributions
to urban atmospheric polycyclic aromatic hydrocarbons andnitropolycyclic aromatic hydrocarbons using 1-nitropyrene
and pyrene: An application to an Asian dust event.
Chemosphere, 2020: 130662. https://doi.org/10.1016/j. chemo
sphere. 2021.130662
IARC (2021) List of classifications agents classified by the
IARC Monographs, Volumes 1–129. Retrieved from: https://monographs.iarc.who.int/ist-of-classifications (accessed 28
August 2023)
Iinuma, Y., Brüggemann, E., Gnauk, T., Müller, K., Andreae, M.,
Helas, G., Parmar, R. and Herrmann, H. (2007) Source
characterization of biomass burning particles: The combustion of
selected European conifers, African hardwood, savanna grass,and German and Indonesian peat. Journal of GeophysicalResearch: Atmospheres, 112: D08209. https://doi.org/10.1029/
2006JD007120
Kitanovski, Z., Shahpoury, P., Samara, C., Voliotis, A. and Lammel,
G. (2020) Composition and mass size distribution of nitrated andoxygenated aromatic compounds in ambient particulate matterfrom southern and central Europe—Implications for the origin.
Atmospheric Chemistry and Physics, 20: 2471–2487. https://doi.
org/10.5194/ acp-20-2471-2020
Kumagai, Y., Arimoto, T., Shinyashiki, M., Shimojyo, N., Nakai, Y.,
Yoshikawa, T. and Sagai, M. (1997) Generation of reactive
oxygen species during interaction of diesel exhaust particle
components with NADPH-cytochrome P450 reductase andinvolvement of the bioactivation in the DNA damage. Free
Radical Biology and Medicine, 22: 479–487. https://doi.org/
10.1016/S0891-5849(96)00341-3

20

K. HAYAKAWA

Kumagai, Y., Shinkai, Y., Miura, T. and Cho, A.K. (2012) The
chemical biology of naphthoquinones and its environmental
implications. Annual Review of Pharmacology and Toxicology,
52: 221–247. https://doi.org/10.1146/annurev-pharmtox-010611134517
Li, Z., Yue, Z., Zhu, W., Liu, W., Gao, J., Zhang, J., Zhan, Z., Chen,
L., Gao, H. and Wei, J. (2023) Sources, compositions, and healthrisks of PM2.5-bound PAHs at the rural area along with the “coalto gas” low. Aerosol and Air Quality Research, 23: 220352.
https://doi.org/10.4209/aaqr.220352
McGrath, T., Chan, W. and Hajaligol, M. (2003) Low temperature
mechanism for the formation of polycyclic aromatichydrocarbons from the pyrolysis of cellulose. Journal of
Analytical and Applied Pyrolysis, 66: 51–70. https://doi.org/
10.1016/S0165-2370(02) 00105-5
Mordukhovichi, I., Beyea, J., Herring, A.H., Hatch, M., Stellman,
S.D., Teitelbaum, D.B., Richardson, D.B., Millikan, R.C., Engel,
L.S., Shantakumar, S., Steck, S.E., Neugut, A.I., Rossner, P., Jr.,
Santella, R. and Gammon, M.D. (2016) Vehicular traffic-related
polycyclic aromatic hydrocarbon exposure and breast cancer
incidence: The long island breast cancer study project (LIBCSP).
Environmental Health Perspectives, 124, 30–38. https://doi.org/
10.1289/ ehp.1307736
Motoyama, Y., Bekki, K., Chung, S.-W., Tang, N., Kameda, T.,
Toriba, A., Taguchi, K. and Hayakawa, K. (2009) Oxidative
stress more strongly induced by ortho- than para-quinoid
polycyclic aromatic hydrocarbons in A549 cells. Journal of
Health Science, 55: 845–850. https://doi.org/10.1248/jhs.55.845
Orakij, W., Chetiyanukornkul, T., Chuesaard, T., Kaganoi, Y.,
Uozaki, W., Homma, C., Boongla, Y., Tang, N., Hayakawa, K.
and Toriba, A. (2017) Personal inhalation exposure to polycyclicaromatic hydrocarbons and their nitro-derivatives in rural
residents in northern Thailand. Environmental Monitoring andAssessment, 189: 510. https://doi.org/10.1007/s10661-017-6220-z
Pham, C.-T., Boongla, Y., Nghiem, T.-D., Le, H.-T., Tang, N.,
Toriba, A. and Hayakawa, K. (2019) Emission characteristics ofpolycyclic aromatic hydrocarbons and nitro-polycyclic aromatichydrocarbons from open burning of rice straw in the north ofVietnam. International Journal of Environmental Research andPublic Health, 16: 2343. https://doi.org/10.3390/ijerph16132343
Pitts, J. S., Lokensgard, D.M., Ripley, P.S., Vancauwenberghe, K.A.,
Vanvaeck, L., Shaffer, S.D., Thill, A.J. and Belser, W., Jr. (1980)
Atmospheric epoxidation of benzo[a]pyrene by ozone-formationof the metabolite benzo[a]pyrene-4,5-oxide. Science, 210: 1347–
1349. https//doi.org/10.1126/science.210.4476.1347
Pitts, J.S. (1983) Review: Formation of fate of gaseous andparticulate mutagens and carcinogens in real and simulated
atmospheres. Environmental Health Perspectives, 47: 115–140.
Shen, H., Huang, Y., Wang, R., Zhu, D., Li, W., Shen, G., Wang, B.,
Zhang, Y., Chen, Y., Lu, Y., Chen, H., Li, T., Sun, K., Li, B., Liu,
W., Liu, J. and Tao, S. (2013) Global atmospheric emissions ofpolycyclic aromatic hydrocarbons from 1960 to 2008 and future
predictions. Environmental Science & Technology, 47: 6415–
6424. https://doi.org/10.1021/es400857z
Straif, K., Cohen, A. and Samet, J. (2013) IARC scientificpublication 161 Air pollution and cancer, IARC, Lyon. ASBN
978-92-832-2166-1. Original: Park, J-H., Penning, M. (2008)
Polyaromatic hydrocarbons. In: Stadler, H. and Lineback, D.R.
(eds.), Process-induced Food Toxicants: Occurrence, Formation,
Mitigation, and Health Risks, Chapter 2, Hoboken, Wiley.
https://doi.org/10.1002/9780470430101
Tomaz, S., Jaffrezo, J.-L., Favez, O., Perraudin, E., Villenave,
E. and Albinet, A. (2017) Sources and atmosphericchemistry of oxy- and nitro-PAHs in the ambient air of Gre

noble (France). Atmosphere Environment, 161: 144–154. https://doi.org/10.1016/j.atmosenv.2017.04.042
Vicente, E.D. and Alves, C.A. (2018) Review: An overview ofparticulate emissions from residential biomass combustion.
Atmospheric Research, 199: 159–185. https//dx.doi.org/10.1016/
j.atmosres.2017.08.027
Vondráček, J. and Machala, M. (2021) Review: The role ofmetabolism in toxicity of polycyclic aromatic hydrocarbons andtheir non-genotoxic modes of action. Current Drug Metabolism,
22: 584–593. https//doi.org/10.2174/138920022199920112520
5725
Wang, S., Bai, Y., Deng, Q., Chen, Z., Dai, J., Li, X., Zhang, W.,
Zhang, X., He, M., Wu, T. and Guo, H. (2016) Polycyclicaromatic hydrocarbons exposure and lung function decline
among coke-oven workers: A four-year follow-up study.
Environmental Research, 150: 14–22. https://doi.org/10.1016/
j.envres.2016.05.025
WHO (2018) Air Pollution and child health: Prescribing clean air.
Retrievedfrom:https//www.who.int./news-room/release(accessed 29 October 2018)
WHO (2023) Air Pollution. Retrieved from: https://www.who.int/
health-topics/air-pollution#tab=tab_1 (accessed 28 August 2023)
Yoshikawa, T., Ruhr, L.P., Flory, W., Giamalva, D., Church, D.F.
and Pryor, W.A. (1985) Toxicity of polycyclic aromatichydrocarbons. 1. Effect of phenanthrene, pyrene, and theirozonized products on blood chemistry in rats. Toxicology andApplied Pharmacology, 79: 218–226.
Zhang, Y., Shen, Z., Sun, J., Zhang, L., Zhang, B., Zou, H., Zhang,T., Ho, S. S. H., Chang, X., Xu, H., Wang, T., Cao, J. (2021)
Parent, alkylated, oxygenated and nitrated polycyclic aromatichydrocarbons in PM2.5 emitted from residential biomass burningand coal combustion: A novel database of 14 heating scenarios.
Environmental Pollution, 268, 115881. https://doi.org/10.1016/
j.envpol.2020.115881.
Zhao, J.Y., Hara, A., Hayakawa, K., Pham, K.O., Suzuki, K.,
Tsujiguchi, H., Matsuzaki, H., Odajima, H., Takami, A. andNakamura, H. (2022) Longitudinal study on the association
between ambient polycyclic aromatic hydrocarbons and nasal
symptoms in adult Japanese. Applied Sciences, 12: 12544.
https//doi.org/10.3390/app122412544

Kazuichi HAYAKAWA
Kazuichi Hayakawa graduated from the
Graduate School of Pharmaceutical Sciences of
the University of Tokyo. He became a research
assistant at Kanazawa University (1977), waspromoted to professor (1996) and then dean offaculty of Pharmaceutical Sciences and directorof the Institute of Nature and Environmental Technology (2012–2015). He
is now a professor emeritus at Kanazawa University. He led the 21stCentury Center of Excellence Program, organized by Japan’s Ministry of
Education, Culture, Sports, Science and Technology (MEXT) from 2002
to 2008. He has been awarded by the Japan Society of Atmospheric
Environment and others, including receiving the Commendation for
Science and Technology from MEXT. His research interests areenvironmental pollution and the health effects of PAHs. He has publishedmore than 400 original papers.

(Received 28 August 2023, Accepted 22 December 2023)