Assessment of Sampling Techniques to Investigate Airborne Transport of Contaminants in Treated Wastewater from Sprinkler Irrigation Fine Droplet

The objective of the present study is to compare different sampling methods in controlled conditions in order to assess which is the most suitable for monitoring bioaerosols and dispersion. Different active sampling techniques were used and their performance assessed at different sampling times: impingement (AGI-4 and SKC BioSampler), filtration (glass fiber filters), and real-time viable particle counter (BioTrak). Two tracers were evaluated, a fluorescent tracer (ABF) and Escherichia coli (E. coli), added to the water. The results showed that the physical collection efficiency of AGI-4 when using ABF, was higher than SKC BioSampler. The sampling time influenced the culturability of E. coli collected by two impingers: with increasing sampling time from 5 min to 15 min, the culturability of E. coli collected by SKC Biosampler and AGI-4 decreased by 14% and 37%, respectively. By comparing the amount of collected E. coli with impingers and those counted by BioTrak, it appears that BioTrak provided a rapid but less accurate number of viable particles.