RESEARCH ARTICLE In vitro effects of pollutants from particulate and volatile fractions of air samples—day and night variability Jiří Novák & John P. Giesy & Jana Klánová & Klára Hilscherová Received: 26 October 2012 / Accepted: 8 April 2013 / Published online: 24 April 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Chemicals in air were characterized for potential interference with signaling of estrogen, androgen, and arylhydrocarbon (AhR) receptors, which are known to play an important role in endocrine-disruptive changes in vivo. Previously, effects of this type have been studied mainly in particulate matter in the ambient air from various localities. In this study, both volatile and particulate fractions of air from three sites in Banja Luka region (Bosnia and Herzegovina) were investigated to describe the distribution of endocrine- disrupting contaminants on a small spatial scale. Circadian variability of air pollution was investigated by collecting samples during both day and night. Air samples collected from urban localities at night were more potent in producing the AhR-mediated effects than those collected during daytime. This trend was not observed at the reference rural location. None of the samples showed significant estrogenic or andro- genic activity. On the other hand, anti-androgenicity was detected in both particulate and vapor phases, while anti- estrogenicity was detected only in the particulate fraction of air from all localities. The AhR-mediated potencies of samples were associated primarily with non-persistent compounds. Based on the concentrations of 28 individual compounds, PAHs accounted for approximately 30 % of the AhR- mediated potency determined by the bioassay. The results show that there can be a significant difference between levels of bioactive compounds in air between daytime and nighttime. Keywords Ambient air . Particulate matter . Gas phase . AhR-mediated toxicity . Estrogenicity . Androgenicity Introduction Pollution of ambient air has been shown to play a role in mediating a range of adverse effects on respiratory, cardiovas- cular, immune, hematological, nervous, and reproductive sys- tems (Curtis et al. 2006). There is an effort to improve guidelines for ambient air quality to protect human health. However, these guidelines are available for relatively few pollutants. Many of them are inorganic constituents of ambi- ent air such as sulfur oxides and nitrogen oxides. Evaluation of the potential risks due to organic contaminants is mostly limited to characterization of individual chemicals in air by use of instrumental analyses. Of the organic compounds of concern, several representatives of indicator classes such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine pesticides (OCPs) are monitored (Holoubek et al. 2007; Klanova et al. 2009). How- ever, air can contain mixtures of numerous pollutants, some of which probably have not been identified yet. These mixtures could potentially produce adverse effects that cannot be pre- dicted only from concentrations of the individual chemicals because the overall toxic outcome could be affected by in- teractions among the effects of the pollutants in the mixtures Responsible editor: Markus Hecker J. Novák (*) : J. Klánová : K. Hilscherová Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic e-mail: novakj@recetox.muni.cz J. P. Giesy Department of Biomedical Veterinary Sciences and Toxicology Centre, University of Saskatchewan Saskatoon, Saskatchewan, Canada J. P. Giesy Zoology Department, Center for Integrative Toxicology, National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI 48823, USA J. P. Giesy Biology and Chemistry Department, City University of Hong Kong, Kowloon, Hong Kong, SAR, China Environ Sci Pollut Res (2013) 20:6620–6627 DOI 10.1007/s11356-013-1726-6