TY - JOUR
T1 - Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems
AU - Benami, Maya
AU - Busgang, Allison
AU - Gillor, Osnat
AU - Gross, Amit
N1 - Funding Information:
The authors acknowledge and thank Madeleine Tierney for her substantial help in the laboratory; Yaniv Kriger for his great patience and support during early morning field samplings; Boris Pritsker for his extensive advice, model parameter explanations, and general experimental planning; Ahuva Vonshak for her advice and lab assistance; and the families who contributed GW to this research. This study was supported by the Rosenzweig-Coopersmith Foundation Grant number 711560 , Zuck Maccabi Fund , and the Israeli Water Authority Grant number 874130 .
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/8/15
Y1 - 2016/8/15
N2 - Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus.According to the settle-plate technique, low amounts (0-9.7 × 104 CFU m-2 h-1) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1 m away from the GW systems. At the 5 m distance amounts of these bacteria were not statistically different (p > 0.05) from background concentrations tested over 50 m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate quantification of small amounts of viable, aerosolized bacterial pathogens.
AB - Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus.According to the settle-plate technique, low amounts (0-9.7 × 104 CFU m-2 h-1) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1 m away from the GW systems. At the 5 m distance amounts of these bacteria were not statistically different (p > 0.05) from background concentrations tested over 50 m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate quantification of small amounts of viable, aerosolized bacterial pathogens.
KW - Aerosols
KW - Enrichment
KW - Greywater
KW - MPN-qPCR
KW - Pathogens
KW - QMRA
UR - http://www.scopus.com/inward/record.url?scp=84963553262&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2016.03.200
DO - 10.1016/j.scitotenv.2016.03.200
M3 - Article
C2 - 27100014
AN - SCOPUS:84963553262
SN - 0048-9697
VL - 562
SP - 344
EP - 352
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -
