Zuckerberg Institute for Water Research, Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben Gurion 84990, Israel.
Zuckerberg Institute for Water Research, Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben Gurion 84990, Israel.
Sci Total Environ. 2016 Aug 15;562:344-352. doi: 10.1016/j.scitotenv.2016.03.200. Epub 2016 Apr 19.
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 (0-9.7×10(4)CFUm(-2)h(-1)) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m 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.
灰水 (GW) 再利用可以通过减少淡水消耗来缓解水资源压力。然而，GW 中含有可能危及公众健康的病原体。在 GW 处理过程中，会产生生物气溶胶，如果被吸入、摄入或接触皮肤，可能对人体健康造成危害。我们使用空气颗粒监测、BioSampler® 和沉降板对来自循环垂直流人工湿地 (RVFCW) 的生物气溶胶进行了采样，RVFCW 是一种家用 GW 处理系统。我们使用沉降板和培养 BioSampler® 液体来监测各种病原体和指示物。利用结合了富集和分子检测 (MPN-qPCR) 优势的新技术，对 BioSampler® 液体中的活病原体进行了进一步计数。此外，还应用定量微生物风险评估 (QMRA) 来评估代表皮肤病原体金黄色葡萄球菌的感染风险。根据沉降板技术，在距离 GW 系统 1 米范围内，发现数量较少（0-9.7×10(4)CFUm(-2)h(-1)）的异养细菌、葡萄球菌属、假单胞菌属、肺炎克雷伯菌、肠球菌属和大肠杆菌会发生气溶胶化，传播距离可达 1 米远。在 5 米距离处，这些细菌的数量与在距离系统 50 米以外检测到的背景浓度没有统计学差异（p>0.05）。使用 BioSampler®，在对 GW 气溶胶进行富集之前，没有检测到细菌。然而，在富集后，使用 MPN-qPCR 技术，偶尔会检测到活的指示物和病原体。因此，在测试的暴露场景下，QMRA 结果低于金黄色葡萄球菌的关键残疾调整生命年 (DALY) 安全限值，这是衡量总体疾病负担的一个指标。我们的研究表明，在 RVFCW GW 处理系统附近，由气溶胶化病原体引起的健康风险可能较低。这项研究还强调了需要标准化生物气溶胶评估技术，以更准确地量化少量气溶胶化的活细菌病原体。
