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Fate of Ascaris at various pH, temperature and moisture levels

Senecal-Smith, Jenna and Nordin, Annika and Vinnerås, Björn (2020). Fate of Ascaris at various pH, temperature and moisture levels. Journal of Water and Health. 18 , 375-382
[Research article]

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Soil-transmitted helminths (STH) are intestinal worms that infect 24% of the world’s population. Stopping the spread of STH is difficult, as the eggs are resilient (can withstand high pH) and persistent (can remain viable in soils for several years). To ensure that new sanitation systems can inactivate STH, a better understanding of their resilience is required. This study assessed the inactivation of Ascaris eggs under various conditions, in terms of moisture content (MC) (90%), temperature (20–50 C) and pH (7–12.5). The results highlight that the exposure of Ascaris eggs to elevated pH (10.5–12.5) at temperatures 27.5 C for >70 days had no effect on egg viability. Compounding effects of alkaline pH (10.5) or decreasing MC (<20%) was observed at 35 C, with pH having more of an effect than decreasing MC. To accelerate the inactivation of STH, an increase in the treatment temperature is more effective than pH increase. Alkaline pH alone did not inactivate the eggs but can enhance the effect of ammonia, which is likely to be present in organic wastes.

Authors/Creators:Senecal-Smith, Jenna and Nordin, Annika and Vinnerås, Björn
Title:Fate of Ascaris at various pH, temperature and moisture levels
Series Name/Journal:Journal of Water and Health
Year of publishing :2020
Page range:375-382
Number of Pages:8
Publisher:IWA Publishing
Publication Type:Research article
Article category:Scientific peer reviewed
Version:Published version
Copyright:Creative Commons: Attribution 4.0
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science
(A) Swedish standard research categories 2011 > 3 Medical and Health Sciences > 303 Health Sciences > Public Health, Global Health, Social Medicine and Epidemiology
Keywords:disease transmission, helminths, nutrient recycling, sanitisation, STH
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Additional ID:
Type of IDID
ID Code:17268
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Energy and Technology
Deposited By: SLUpub Connector
Deposited On:18 Aug 2020 07:13
Metadata Last Modified:15 Jan 2021 19:46

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