View source for Case Study 2: Biosolids

This page is intended as a structural template for editors to use in adding their own case studies to the wiki.
=The Problem=
This section describes the scenario you are going to be modeling.  This could in paragraph format describing a real world question health professionals or policy makers may need to know.
=Hazard ID=
This section is where you can research the pathogens you may be encountering in this scenario.  In some cases you may know ahead of time which specific pathogen you are modeling.  In other cases it will be more variable based on the particular environment.  You may even be dealing with multiple organisms.  Once the organisms are known, research them to determine transmission routes, case-fatality ratios, epidemiological histories, etc.  More information on this section is available at the [[Hazard Identification (Home Page) | hazard identification home page]].
=Exposure Assessment=
In this section, you explore every pathway the pathogen can take from source to host.  It can take considerable time, research and creativity to accurately model all the relevant parts.  More information on this section is available at the [[Exposure Assessment (Home Page) | exposure assessment home page]].
=Dose Response=
This is the more mathematically intensive of the sections.  Here you establish the type of model you will apply once you finish the exposure and hazard id.  There are two basic equations you could use and countless possibilities for the variables.  More explanation and a compilation of dose-response models is available at the [[Dose Response (Home Page) | dose-response home page]]
=Risk Characterization=
Once the exposures are understood and the dose-response relationship is known you can then put these parts together to provide a probability of infection based on a single time period or incidence.  For more information and additional examples, visit the  [[Risk Characterization (Home Page) | risk characterization home page]].
=Risk Management=
Now that you know the nature of the risk, you can start to explore the various methods of reducing that risk.  While this appears to be a more traditional form of environmental health, pairing it with the risk assessment framework you will know have an well developed idea of what parts of the infection chain would be most appropriate to target.  This would be either because a certain part contributes a considerable amount of risk or because it is easily addressed.  Also part of risk management is mathematica cost and effectiveness models that guide you as to how to carry out these management strategies.  More information available at the [[Risk Management (Home Page) | risk management home page]]

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===References===
Galada, et al. Development of failure scenarios for biosolids land application risk assessment. Water Environmental Research. 2013; 85(2):141-150

Mazari-Hiriart, et al. Microbiological implications of periurban agriculture and water reuse in Mexico City. Plos One. 2008; 3(5):e2305

Jimenez, et al. Treatment technology and standards for agricultural wastewater reuse: A case study in Mexico. Irrigation and Drainage. 2005; 54(1):S23-S33

Wong K, et al. Quantification of enteric viruses, pathogen indicators, and Salmonella bacteria in class B anaerobically digested biosolids by culture and molecular methods. Applied and Environmental Microbiology. 2011; 76(19):6441-6448.

Tanner, B. D., Brooks, J. P., Gerba, C.P., Haas, C.N., Josephson, K L. and Pepper, I.L. 2008. Estimated occupational risk from bioaerosols generated during land application of class B biosolids. J. Environ. Qual., 37: 2311-2321.

Sidhu, J.P.S, and Toze. S.G. 2009. Human pathogens and their indicators in biosolids: A literature review. Environ. Int. 35:187-201.