Semivolatile Organic Compounds (SVOCs) in the atmosphere of Santiago de Cali, Valle del Cauca, Colombia along north-south transect using polyurethane foam disk as passive air samplers

Abstract

A preliminary evaluation of Semivolatile Organic Compounds (SVOCs) was performed in the atmosphere of Santiago de Cali, Colombia, using passive air samplers based polyurethane foam (PAS-PUF) disks. PAS-PUF were deployed in four sites, along a north-south transect(∼15 km), during one sampling period of ∼4 months in 2011, form the industrial area of Yumbo (EF site) to the agricultural area of Valle del Cauca (FCNE). Results showed, for PCBs and PAHs, a clear north-south (IN > AG) decreasing concentration gradient (∼3 times) while OCPs exhibited an opposite gradient (UR < AG). Endosulfan I showed the highest concentrations in air (∼0.8–60 ng m−3). The HCHs (α- and γ-) concentrations ranged from BDL to ∼19 ng m−3, with α-HCH showing the highest levels (suggesting recent use of technical HCHs) and for DDTs levels fluctuated from BDL to ∼29 ng m−3 (with p,p’-DDE accounting for 50–80% of total DDTs). PAHs levels (∼25–66 ng m−3) were characterized by the abundance of Phenanthrene (34%), fluoranthene (18%) and pyrene (16%). For PCBs, concentrations in air ranged from ∼0.2 to 0.9 ng m−3 and were characterized by middle to a higher molecular weight PCB composition pattern. The results of OCPs are much higher than those found in other areas of Latin America. These results are likely influenced by the proximity of agricultural cultivations (i.e., sugarcane crops) in the southern part of the city. These results provide preliminary information about the presence of SVOCs in the atmosphere of Santiago de Cali, and constitute the basis for future monitoring programs.