Department of Environment and Agriculture, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
CSIRO Land and Water, EcoSciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
Water Res. 2014 Aug 1;59:185-97. doi: 10.1016/j.watres.2014.03.037. Epub 2014 Apr 4.
There is a growing need for better assessment of health risks associated with land-applied biosolids. This study investigated in-situ decay of seeded human adenovirus (HAdV), Salmonella enterica, Escherichia coli, and bacteriophage (MS2) in biosolids-amended soil under wheat cultivation. The biosolids seeded with microorganisms were placed in decay chambers which were then placed in the topsoil (10 cm depth) at three different sites. Sites were selected in arid wheat-growing regions of Australia with loamy-sand soil type (Western Australia) and sandy soil (South Australia). Seeded E. coli and S. enterica had a relatively short decay time (T90 = 4-56 days) in biosolids-amended soil compared to un-amended soil (T90 = 8-83 days). The decreasing soil moisture over the wheat-growing season significantly (P < 0.05) influenced survival time of both bacteria and MS2 at Western Australia (Moora) and South Australia (Mt Compass) sites, particularly in the un-amended soils. Increasing soil temperature also significantly (P < 0.05) influenced the decay of MS2 at these sites. In this study, no notable decline in HAdV numbers (PCR detectable units) was observed in both biosolids-amended and the un-amended soils at all three sites. The HAdV decay time (T90 ≥ 180 days) in biosolids-amended and un-amended soils was significantly higher than MS2 (T90 = 22-108 days). The results of this study suggest that adenovirus could survive for a longer period of time (>180 days) during the winter in biosolids-amended soil. The stability of adenovirus suggests that consideration towards biosolids amendment frequency, time, rates and appropriate withholding periods are necessary for risk mitigation.
人们越来越需要更好地评估与土地应用生物固体相关的健康风险。本研究调查了在小麦种植下，接种了人类腺病毒（HAdV）、沙门氏菌、大肠杆菌和噬菌体（MS2）的生物固体在添加生物固体的土壤中的原位衰减情况。将接种了微生物的生物固体放置在衰减室中，然后将其放置在三个不同地点的表土（10 cm 深度）中。这些地点是在澳大利亚干旱的小麦种植区选择的，土壤类型为壤土-沙土（西澳大利亚州）和沙土（南澳大利亚州）。与未添加生物固体的土壤相比，添加生物固体的土壤中接种的大肠杆菌和沙门氏菌的衰减时间（T90=4-56 天）相对较短。在小麦生长季节，土壤水分不断减少，这显著影响了西澳大利亚州（穆拉）和南澳大利亚州（芒特康帕斯）两个地点的细菌和 MS2 的生存时间，特别是在未添加生物固体的土壤中。土壤温度的升高也显著（P<0.05）影响了这些地点 MS2 的衰减。在本研究中，在所有三个地点，未添加生物固体和添加生物固体的土壤中，HAdV 的数量（PCR 可检测单位）均未明显下降。在添加生物固体和未添加生物固体的土壤中，HAdV 的衰减时间（T90≥180 天）明显长于 MS2（T90=22-108 天）。本研究结果表明，腺病毒在添加生物固体的土壤中冬季可以存活更长时间（>180 天）。腺病毒的稳定性表明，有必要考虑生物固体的添加频率、时间、速率和适当的搁置期，以降低风险。
