Elisabeth:

Thanks...well put.

David

Thanks for the link to the paper Joe. I will include aspects of this in my lecture notes.

Hi!

Thank you for your answer. And the Wikipedia essay was very helpful.

What was most interesting is the solution: heating to above 40C and removing moisture is quite feasible with a dry toilet.

We will look into this more carefully.

And thank you once again!

With kind regards,

Vishwanath

Dear David,

About your question regarding urine and schistosomiasis, I think I can help you out with that reference that you were trying to remember.
But firstly for those who don't know:
Schistosomiasis is a helminth infection and is counted as a neglected tropical disease. The Wikipedia page on Schistosomiasis is pretty good (I also did some work on editing it in the past, e.g. the picture in the lead was added by me, after I hunted around for additional pictures for quite some time):
en.wikipedia.org/wiki/Schistosomiasis

About the question of urine being sterile or urine transmitting diseases, I also investigated that as part of my work on the UDDT page of Wikipedia. I used to think "urine is sterile" and no need to worry about it. But I've learned urine is not sterile and you do need to worry about it a little bit but nowhere near as much as worrying about feces in terms of disease transmission.

Here is the relevant text on Wikipedia that Kai Forlie (another SuSanA member and active forum user: forum.susana.org/forum/profile/userid-3842) helped me to write:
en.wikipedia.org/w/index.php?title=Urine...ing_dry_toilet#Urine

Urine
Further treatment
The required degree of treatment for the collected urine depends entirely on whether this product will be reused in agriculture. If it is not reused but only infiltrated then no further treatment is required.

Urine that leaves the body of a healthy person is practically sterile and therefore would not require treatment for pathogen removal. However, a contamination of urine with fecal pathogens is possible if the UDDT is not used correctly, i.e. when some fecal matter finds its way into the urine compartment.[17] Also, for a few specific diseases, the relevant pathogens may be found in the urine; for example: Leptospira interrogans, Salmonella typhi, Salmonella paratyphi, Schistosoma haematobium, BK virus or Simian virus.[14][18][19][20] The Ebola virus may also be found in urine from an infected person. The exact survival time of this particular virus in human urine outside of the human body is unclear but probably "up to several days" like with other body fluids at room temperature.[21]

For these reasons, urine should always be treated for pathogen removal if it is going to be reused, unless reuse occurs at the same household where the urine was collected and on crops that are only consumed by these household members (in which case an infection amongst family members is more likely to occur via handshakes and hugs than via urine reuse activities).[22]

The simplest and most common method of urine treatment for pathogen removal is via storage in closed vessels. The decomposition of urea that is present in urine into ammonia and hydrocarbonate leads to an increase in ammonia concentration and an increase of pH value to above 9. These two processes, and simply "time" as the third process, are effective in killing of pathogens. They are more efficient in warm temperatures and with low dilution of the urine with water.[2]

Storage of urine kills bacterial pathogens encountered in urine – including Salmonella typhi and paratyphi and Mycobacterium tuberculosis – in a relatively short time span: a storage time of five weeks at temperatures below 20 °C or of two weeks at temperatures above 20 °C has been recommended to prevent transmission of mycobacteria when recycling human urine.[23]

Recommended storage times to kill pathogens in urine vary from one to six months depending on ambient temperatures, the scale of the urine collection system and which crops will be fertilised with the urine.[22]

Note the numbers in square brackets are the reference numbers. You can click on the references when you read the Wikipedia article.

Isn't Wikipedia becoming a great source of knowledge and a great tool for knowledge management?

I have asked the expert on urine and diseases, Björn Vinneras, to also review this section and he's promised me to do so (since a few months), hopefully he will get around to it.
Things are never perfect on Wikipedia.


Dear Vishwanath,

Yes, I think it's fair to say that with regards to fecal sludge, or solids from UDDTs, it is the helminth eggs that you need to worry about, not E. coli, because the helminth eggs are so much harder to destroy.
You can also read here on Wikipedia about it, a section that I co-edited about helminth eggs as an indicator organism:
en.wikipedia.org/wiki/Helminths#Indicator_organism
(if anyone wants to suggest improvements to this paragraph, feel free)

Regards,
Elisabeth

Hi all, I am just entering this field but I already see Helminths being discussed as a bigger problem than e-coli (which I expected to be the main problem). I would really appreciate some pointers about the thinking in fecal matter handling. Thanks!


And I do apologise if this is the wrong Topic for this question.

Cristoph:

That is a belief that I reached many years ago from a literature review and article that I read long ago, and I have not questioned it until you just challenged it. Yes I understand your point about relative risk compared to other technologies. Point taken.

From what I remember, the article was very supportive of UDDT's...it was just clarifying that if there was urinary schistosomiasis, you shouldn’t just implement the technology without taken controls.

I think my point is to clarify now is that if releasing urine contaminated with schistosomiasis into the ground, and potentially ground water, and potentially near shallow wells, is considered a risk, perhaps the urine should be captured and undergo some type of treatment before disposal and/or reuse, or some types of controls with the collection and disposal.

I believe that use of special controls in those communities should be considered. I have personally seen the urinal hoses get stopped up many times causing urine to puddle in the urinal, and also have seen the absorption pits get clogged and urine puddle on the surface of the ground. If there is schistosomiasis, then seems reasonable to consider more controls in those communities.
I don't know much about urinary schistosomiasis....I believed what I read long ago.....if there is current literature indicating that urinary schistosomiasis is not a significant threat in the circumstances I cited, then I may change my belief.

I would have to dig hard to find that source....I cited it in my first paper on on-site sanitation in 1984. I don't know I even have a copy of that paper with me here in Japan. I will look.

My general attitude about UDDT’s is that care needs to be taken in their design, construction and O&M. I have seen groups that have promoted them too aggressively without adequate controls and inadequate follow up. My dissertation is on UDDTs and I believe it is a good technology with a lot of promise, however I have seen a lot of failures with them. I think they require a lot of investment of education of the users, and financial investment from them to take them serious.

Dear David,

I don´t understand were you draw the conclusion that

UDDT's we have been discussing is that it is not recommended in the literature to use UDDT's in communities where there is a prevalance of urinary schistosomiasis.

a) could you give the literature that UDDT are more critical than other toilets (which)?

b) could you explain to me why you believe that? In my understanding the infiltration of urine is equivalent to the infiltration in a pit or after a septic tank...???

c)Why do you think that the article supports Joes concern about UDDT and helminth eggs. I agree with Joe on the concern about helminth eggs, but from the available technologies (Pit, septic tank, or UDDT) I find the UDDT the best of these concerning security. Do you disagree and if yes why?

Christoph

Interesting study Joe.

The article stated: "....increasing evidence links the major neglected tropical diseases (NTDs) to a significant adverse impact on both human and economic development, especially for the major helminth infections, i.e. intestinal helminth infections, schistosomiasis, and lymphatic filariasis .

One thing that can be pointed out here about the UDDT's we have been discussing is that it is not recommended in the literature to use UDDT's in communities where there is a prevalance of urinary schistosomiasis....because there typically really is no treatment of the urine...it is just disposed in an absorption pit.

And the article supports your concerns about the UDDT's where the helminths or helminth eggs surviving in UDDT solids.

An interesting new study in the open-access journal PLOS Neglected Diseases:

I am not sure what to post here from the study - but it is basically saying that too little notice is being given of helminth infections and that policies to tackle them, such as deworming, should "should become an essential component of the SDGs"

The full paper is here: journals.plos.org/plosntds/article?id=10...journal.pntd.0003618

+++++
Note by moderator:

Title:

Helminth Elimination in the Pursuit of Sustainable Development Goals: A "Worm Index" for Human Development
Peter J. Hotez , Jennifer R. Herricks

Published: April 30, 2015DOI: 10.1371/journal.pntd.0003618