“…However, it is possible that other substances that were not measured have also influenced the toxicity of rainwater samples. Notably, oxidants, such as H 2 O 2 in rainwater and O 3 in gaseous phase, have been historically observed in the MASP atmosphere during spring and summer, which are the rainy seasons (CETESB 2009;Fontenele et al 2009;Gonçalves et al 2010), and, as oxidants are highly reactive, their contribution to toxicity cannot be neglected. In addition, considering the large automotive fleet in MASP (Miraglia et al 2005), hydrocarbons, aldehydes, and some metals, together with SO x , NO x , and other ions, are emitted by such sources (Bourotte et al 2006;Castanho and Artaxo 2001;Fornaro and Gutz 2006) and may possibly contributed to the observed toxicity.…”