Thank you all for your comments

I can't see anything there from Chris Buckley and his team, for example

www2.gtz.de/Dokumente/oe44/ecosan/en-hea...ion-toilets-2008.pdf

Yes Joe. I am looking for data that I can feed into my QMRA model. Yes, table 2 is the kind of data I am looking for.

Makowka - Yes, I did go through that document. A very useful compilation. Page 58 lists the exposure pathways but, as suggested by you, writing to the authors might give some pointers to dosage estimation.

Elisabeth - My study is objective based - What are the health risks associated with faecal sludge reuse in India?

Here is a brief list of literature related to QMRA and dosage estimation that I have gone through, so far.

1. Amoah, P., B. Keraita, M. Akple, P. Drechsel, R. C. Abaidoo, and F. Konradsen. 2011. “Low-Cost Options for Reducing Consumer Health Risks from Farm to Fork Where Crops Are Irrigated with Polluted Water in West Africa”. International Water Management Institute. www.iwmi.cgiar.org/publications/iwmi-res...-research-report-141.
2. Brooks, John P., Charles P. Gerba, and Ian L. Pepper. 2009. “Comparative Microbial Risks of Land Applied Biosolids and Animal Manure.” Proceedings of the Water Environment Federation 2009 (3): 161–73.
3. Guzmán, C., J. Jofre, M. Montemayor, and F. Lucena. 2007. “Occurrence and Levels of Indicators and Selected Pathogens in Different Sludges and Biosolids: Indicator and Pathogens in Sludges.” Journal of Applied Microbiology 103 (6): 2420–29. doi:10.1111/j.1365-2672.2007.03487.x.
4. Haas, Charles N., Joan B. Rose, and Charles P. Gerba. 1999. Quantitative Microbial Risk Assessment. John Wiley & Sons.
5. Pepper, Ian L., John P. Brooks, and Charles P. Gerba. 2006. “Pathogens in Biosolids.” In Advances in Agronomy, 90:1–41. Elsevier. linkinghub.elsevier.com/retrieve/pii/S0065211306900017.
6. Razak Seidu, Pay Drechsel, Philip Amoah, Owe Lofman, Arve Heistad, and Madeline Fodge. 2008. “Quantitative Microbial Risk Assessment of Wastewater and Faecal Sludge Reuse in Ghana.” In . wedc.lboro.ac.uk/resources/conference/33/Seidu_R.pdf.
7. Rusin, P., S. Maxwell, and C. Gerba. 2002. “Comparative Surface-to-Hand and Fingertip-to-Mouth Transfer Efficiency of Gram-Positive Bacteria, Gram-Negative Bacteria, and Phage.” Journal of Applied Microbiology 93 (4): 585–92.
8. Schönning, Caroline, Therese Westrell, Thor Axel Stenström, Karsten Arnbjerg-Nielsen, Arne Bernt Hasling, Linda Høibye, and Anders Carlsen. 2007. “Microbial Risk Assessment of Local Handling and Use of Human Faeces.” Journal of Water and Health 5 (1): 117. doi:10.2166/wh.2006.049.
9. Teng, Jingjie. 2012. “Microbial Risk Assessment Modeling for Exposure to Land-Applied Class B Biosolids”. Drexel University. idea.library.drexel.edu/handle/1860/3857.
10. Teng, Jingjie, Arun Arun Kumar, Patrick L. Gurian, and Mira S. Olson. 2013. “A Spreadsheet-Based Site Specific Risk Assessment Tool for Land-Applied Biosolids.” Open Environmental Engineering Journal 6. search.ebscohost.com/login.aspx?direct=t...Dkfi8IUg%3D%3D&crl=c.
11. US EPA. 1994. “A Plain English Guide to the EPA Part 503 Biosolids Rule.”
12. ———. 2011. “Exposure Factors Handbook: 2011 Edition”. EPA. www.epa.gov/ncea/efh/pdfs/efh-complete.pdf.
13. Ware, George W., ed. 1993. Reviews of Environmental Contamination and Toxicology. Vol. 132. Reviews of Environmental Contamination and Toxicology. New York, NY: Springer New York. link.springer.com/10.1007/978-1-4684-7065-9.
14. Westrell, T, C Schönning, T A Stenström, and N J Ashbolt. 2004. “QMRA (quantitative Microbial Risk Assessment) and HACCP (hazard Analysis and Critical Control Points) for Management of Pathogens in Wastewater and Sewage Sludge Treatment and Reuse.” Water Science and Technology: A Journal of the International Association on Water Pollution Research 50 (2): 23–30.
15. Wheeler, D, and RF Carroll. 1989. “The Minimisation of Microbiological Hazards Associated with Latrine Wastes.” www.iwaponline.com/wst/02103/0035/wst021030035.pdf.
16. WHO. 2006. Guidelines for the Safe Use of Wastewater, Excreta and Greywater. Geneva: World Health Organization.
17. Yen-Phi, Vo Thi, Andrea Rechenburg, Björn Vinneras, Joachim Clemens, and Thomas Kistemann. 2010. “Pathogens in Septage in Vietnam.” Science of The Total Environment 408 (9): 2050–53. doi:10.1016/j.scitotenv.2010.01.030.

Here is a brief summary of how the above literature relates to my study:

• (Razak Seidu et al. 2008) study assesses the microbial risk of fecal sludge reuse in Ghana. Study focuses on Rotavirus and Ascaris. Concentration of pathogens is derived from a 1989 study of pit latrines in Bostwana (Wheeler and Carroll 1989) and ingestion quantity was assumed to be 200mg and 100mg for adults and children respectively based on (WHO 2006). Only exposure route is ingestion. Inhalation and dermal contact is not considered.

• (Brooks, Gerba, and Pepper 2009) study compares microbial risks of land applied bio-solids and animal manure. Paper provides Class B Biosolids, Manure, and Raw Sludge Data Values, Soil and Crop Microbial Loads. The study considers ingestion and fomite transfer (Rusin, Maxwell, and Gerba 2002) but not inhalation or dermal contact.

• (Schönning et al. 2007) study assesses the microbial risks of local handling and use of human feces. Study considers only ingestion as the exposure route. The exposure is assumed to take place during one of three events, when accidental ingestion of small amounts of faeces, or faeces and soil mixture, may occur: Emptying of the container and distribution of the material, Recreational activities in the garden, Gardening. The faeces-soil intake was based on a literature study by Larsen (1998), where children are estimated to ingest around 200 mg of soil per day on average with an absolute maximum of 5–10 g per day occurring once every ten years by exposure each day. It was further assumed that adults ingest 15–50% of this amount, with a maximum of 100mg.


• (Amoah et al. 2011) study considers only fecal coliforms and helminth eggs. Uses HACCP to provide low-cost options to reduce health risks from farm to fork where crops are irrigated with polluted water. Does not use QMRA, but a good example of how HACCP can be used in my study.

• (Westrell et al. 2004) study applies QMRA and HACCP to identify and control exposure to pathogenic microorganisms encountered during normal sludge and wastewater handling at a treatment plant utilising tertiary wastewater treatment and mesophilic sludge digestion. Hazards considered - rotavirus, adenovirus, haemorrhagic E. coli, Salmonella, Giardia and Cryptosporidium.

This study is most relevant to my study. It involves HACCP and QMRA. It considers ingestion and inhalation but not dermal contact. Though the study provides an estimate of volume ingested, it does not explain the rationale behind that estimate.

• (Guzmán et al. 2007) Study aims at determining the occurrence and levels of pathogens and indicators in raw and treated sludges and compare their persistence after two different treatments.

• (Teng 2012) For land-applied bio-solids, studies have found that the accidental direct ingestion produced the highest annual risk, inhalation produced the next highest risk, and that risks from groundwater and direct ingestion of contaminated food were low.

• (Teng et al. 2013) study developed and applied a spreadsheet-based tool, named The Spreadsheet Microbial Assessment of Risk: Tool for Biosolids (SMART Biosolids), which links quantitative microbial risk assessment with microbial fate and transport modeling. The SMART Biosolids model estimates risk associated with exposure to pathogens from land-applied biosolids through five pathways: inhalation of aerosols from land application sites, consumption of groundwater affected by land-applied biosolids, direct ingestion of biosolids-amended soils, consumption of water contaminated by runoff from a land application site, and ingestion of plants impacted by land-applied biosolids. Currently the model is able to quantify risks for six pathogens: Giardia lamblia, Cryptosporidium, Salmonella, Shigella, enterovirus, and adenovirus, and examine the exposure concentrations for four indicators: coliphage, E.coli, Enterococci, and fecal coliforms.

• (Pepper, Brooks, and Gerba 2006) – provides a list of pathogens in biosolids. It discusses the nature of sewage (what it is comprised of) but not the pathogen concentration in sewage. The study lists endotoxin concentration in aerosols.

This overview publication also shortly discusses it (p.58) , and it might be worth asking the authors to comment (since they are SuSanA partners).

is table 2 of this paper the kind of thing you want?

www.iwaponline.com/jwh/005/0117/0050117.pdf

Are you getting the data for a QMRA? Even if not, you might want to look into QMRA to get the assumed dose levels for emptying latrines. Chris Buckley might have some leads on that, it looks like he has published a few papers doing these kinds of calculations.

Ah, I see (sorry for misundertanding the word "ingestion" at first). I have modified the thread title accordingly, to make it clearer. Is it OK like this for you?

We had a similar discussion on health guidelines for pit emptiers started by Doreen Mbalo from GIZ in Kenya please see here:
forum.susana.org/forum/categories/53-fae...-exhauster-operators

Maybe there is something useful in there or you could ask her in that thread what the final outcome was. The colleagues in South Africa are also very advanced on that topic (see last post in that thread from Bobbie Louton from a year ago: forum.susana.org/forum/categories/53-fae...mit=12&start=12#3733)

And I am curious: in which context are you conducting this study, for whom and with which partners? If it's part of your PhD then what is the research hypothesis that you are trying to prove or disprove?

Regards,
Elisabeth

I don't think this paper quantifies the risks, but at least discusses them:

www.ncbi.nlm.nih.gov/pmc/articles/PMC2796749/

Thank you Makowka for the definition. You are right. I am focusing on the health risks.

Elisabeth - Dr.Parkinson is interested in the amount of faecal sludge generated per person per day. My question is about how much sludge is accidentally ingested into the body of the workers who empty the pits manually or mechanically.

Thanks for providing the links to the documents. They will definitely help me with the understanding of business practices. But neither of them has any information about the ingestion. Finding that estimate has been a challenge.

If any of you have any ideas about how I can extrapolate the ingestion quantity from other studies, please let me know.

I am working on a brief report on Nepal. There are some gaps and hence the delay. I will keep you all posted about my findings.

Na, he is referring to worker's health risks.

A good overview is here . Quote:

Ingestion is the major route of spread of infection from sewage to workers. This is likely to occur during splashes, and hand-to-mouth contact i.e. eating, drinking, smoking or wiping the face with contaminated hands.

Dear Sharada,

Isn't this the same question that we have been discussing in great depth (thanks to all the contributors!) in this thread:
forum.susana.org/forum/categories/53-fae...-from-pits-tanks-etc
?

If not, what is different in your question now, except that it is specific to India?

By the way, the term "ingestion" here seems strange to me. What do you mean - sounds like the BMGF (Bill & Melinda Gates Foundation) term omni-ingestor . It is just the act of pumping into a vessel on a tank (vacuum truck), isn't it?

In case you haven't found it yet, make sure you study this document for India:

Bhat, N., Vashishta, A., Baskaran, C., Chopra, N. (2011). Landscape Analysis and Business Model Assessment in Fecal Sludge Extraction and Transportation Models in India. Consultancy report by The Right Angle commissioned by Bill & Melinda Gates Foundation, Seattle, USA.
susana.org/lang-en/library?view=ccbktypeitem&type=2&id=1668

and
Menon, M. H. (2012). Landscape Study of Potential Investment Funds for Fecal Sludge and Resource Recovery in India - External report. Consultancy report commissioned by Bill & Melinda Gates Foundation, Seattle, USA.
susana.org/lang-en/library?view=ccbktypeitem&type=2&id=1639

If you have questions on those, you could ask the authors here on the forum (and alerting them by e-mail to your post)

Regards,
Elisabeth

P.S.
By the way, can you please give an update on your research work in Nepal about which you posted a year ago here:
forum.susana.org/forum/categories/17-fer...sludge-in-nepal#4125
("My study has two objectives: why do farmers use or don't use fecal sludge?
Why do business transport or don't transport fecal sludge to the farms?")
Thanks.

I am trying to estimate the quantity of fecal sludge (not biosolids) ingested by vacuum truck operators during collection, transport, and disposal in India. Sampling the hands of the tank emptiers to calculate the quantity of sludge is not feasible. I could not find any reliable source on quantity estimation.

EPA provides biosoilids, not manure derived from drying untreated fecal sludge, ingestion quantities for farmers (via soil ingestion, inhalation, dermal contact). I could not find the assumptions / conditions EPA considers for that ingestion. Also there are studies which estimate the quantity ingested by treatment plant workers. I could not find anything related to raw fecal sludge ingestion.

What makes concentration and ingestion more challenging is the level of decomposition of sludge in Indian pits. Septic tanks in India are mostly cess pits of varied dimensions. The collection and decomposition of the sludge depends on the depth of the pit, the lining, and the characteristics of the soil around the pit.

Any pointers to calculate the concentration and ingestion of fecal sludge for truck operators is highly appreciated. Thanks.