###### Abstract  
Polycyclic aromatic hydrocarbons (PAHs) and hydroxylated PAHs (OH-PAHs) are ubiquitous atmospheric pollutants that are a concern because of their endocrine disrupting activities. In this study, seasonal air sampling was conducted in 2017 and 2018 in Kanazawa, Ishikawa Prefecture, Japan. The concentrations and seasonal variations of PAHs and OH-PAHs were analyzed, and health risks of individual congeners were evaluated based on their relative endocrine activity. The atmospheric concentrations of PAHs and OH-PAHs showed seasonal trends with higher concentrations in the winter (daily average \(\pm\) standard deviation: 1.00 \(\pm\) 0.26 ng/m\({}^{3}\) for PAHs and 75.06 \(\pm\) 23.38 pg/m\({}^{3}\) for OH-PAHs) and lower concentrations in the summer (0.30 \(\pm\) 0.09 ng/m\({}^{3}\) for PAHs and 17.08 \(\pm\) 4.83 pg/m\({}^{3}\) for OH-PAHs). There were significant positive correlations between the concentrations of atmospheric PAHs and OH-PAHs. Additionally, the health risk from the endocrine disrupting potential of each OH-PAH was evaluated using relative estrogenic and antistrogenic activities. OH-PAHs with four rings, such as OH-chrysenes and OH-benz[\(a\)]anthracene, had particularly high health risks. These results suggest that atmospheric OH-PAHs are a potential health risk for organisms and thus warrant further research. polycyclic aromatic hydrocarbon; hydroxylated polycyclic aromatic hydrocarbon; atmospheric pollution; health risk; endocrine disrupting chemical; seasonal variability +
Footnote †: journal: Applied Sciences  
Interest in the health risks and atmospheric behavior of oxidized derivatives of PAHs is growing rapidly, and many studies have been conducted [15; 16]. One group of PAH derivatives, hydroxylated PAHs (OH-PAHs), has been detected in the atmosphere [17; 18; 19; 20; 21; 22; 23; 24]. OH-PAHs are oxidized derivatives of PAHs that are generated via combustion of organic matter such as tobacco, wood, and fossil fuel [17; 21; 25]. The OH-PAHs can also be generated via hydroxyl (OH) radical-initiated reactions in the atmosphere [26; 27; 28; 29]. In a study in China, [PERSON] et al. [22] found that biomass burning is the dominant source (79.6%) of atmospheric OH-PAHs during colder seasons when domestic heating appliances are used, whereas traffic emissions (59.6%) and secondary formation (21.7%) are the dominant sources in the warmer seasons. OH-PAHs have high health risks, with their endocrine disrupting potential being of particular concern [8; 12; 20; 30; 31; 32]. In a previous study, [PERSON] et al. [30] evaluated the relative estrogenic and antiestrogenic activities of 14 PAHs and 63 OH-PAHs. In their study, OH-PAHs with four rings, such as hydroxylated benz[\(a\)]anthracenes, hydroxylated chrysenes, and hydroxylated benzo[\(c\)]phenanthrene, showed strong estrogenic and antiestrogenic activity. Hydroxylated PAHs with four rings, especially hydroxylated chrysene, have a similar chemical structure to 17\(\beta\)-estradiol (estrogen). Consequently, several OH-PAHs can interact with the human estrogen receptor (hER). The hER includes ER\(\alpha\) and ER\(\beta\), which have similar binding affinities but different distributions in the tissues. It is believed that endocrine disrupting chemicals, such as OH-PAHs, bind to ERs and induce estrogenic and antiestrogenic activity [20; 30]. Previous studies have revealed that OH-PAHs have much higher teratogenicity and developmental toxicity in fish compared to their parent PAHs [32; 33]. While OH-PAHs are of toxicological concern, little is known about the seasonal variations in atmospheric OH-PAH concentrations [18; 21]. In addition, a comprehensive toxicological risk assessment, especially on the estrogenic and antiestrogenic activities of atmospheric OH-PAHs towards humans, has not been conducted. In this study, seasonal air sampling was conducted in 2017 and 2018 at Kanazawa, Ishikawa Prefecture, Japan. The concentrations and seasonal variations of airborne particle-bound PAHs and OH-PAHs were analyzed.