Passive air sampling (PAS) using polyurethane foam (PUF) disks has been used to monitor air contamination from current-use pesticides (CUPs). However, its accuracy has hardly been studied. To assess effectiveness of PUF-PAS for measuring CUPs, 18 PUF-PAS devices were deployed for 1-6 weeks at a school near banana plantations in Costa Rica. Simultaneously, every week air was sampled with high and low volume active air samplers (AAS) for 24 h and 7 days, respectively. Extracts were analyzed using microwave-assisted extraction and LC-MS/MS. Nine CUPs (ethoprophos, difenoconazole, cadusafos, chlorpyrifos, fenpropidin, fenpropimorph, pyrimethanil, spiroxamine, and terbufos) were detected by both PAS and AAS. Concentrations were highest for pyrimethanil (34.3 ng/m3) followed by fenpropidin (9.0 ng/m3) and terbufos (8.4 ng/m3). An average sampling rate of 3.4 m3/day was estimated for PUF-PAS using Lo-AAS data, like previously reported in literature. After 3 weeks of deployment, PUF-PAS detected eight out of nine pesticides, similar to the AAS methods. However, after 4 weeks of deployment, substantial losses (≥50%) were observed for all CUPs except pyrimethanil, likely due to oxidative degradation. We therefore recommend a maximum deployment time of 3 weeks under tropical conditions. These findings support PUF-PAS as a cost-effective alternative for AAS in tropical regions.
Díaz et al. (Wed,) studied this question.