4 QMRA Model from FAO WHO​ (Reviewed by Dr. Chea Rortana) 13 09 2025.pdf

This presentation is used for educational purposes only
DVM class, Cambodia
The reviewer will accept any comment to improve this knowledge for better education

1. ការវិភាគហានិភ័យននពាណិជ្ជកម្មសត្វ
និងផលិវផលមានដ ើមសកម្ំដណើវ្វ
Risk Analysis for Trade in Animals and Animal
Products

2. ការវិភាគហានិភ័យ៖ សេចក្តីស្តើម
(Risk Analysis: Introduction)
ដរៀបចំដោយ៖ បណឌិវ ជា រវនា
វិទ្យាស្ថានជាវិស្រស្ថវស្រជាវ្ុខភាព្វ និងផលិវកម្មសត្វ អគគនាយកម្ោាន្ុខភាព្វ និងផលិវកម្មសត្វ

3. What are the meaning from these picture?
RiskHazard Unwanted consequence

4. មាវិកា
•ដោលបំណងដមសដរៀន
•ដ្ចកម្តីដផតើមស
•Risk analysis
•Type of risk analysis
•Qualitative and Quantitative Risk
analysis
•Application of Risk analysis
•Group Assignment
•Presentation
•Exam

6. Quiz 1: Introduction to Risk analysis
•https://forms.office.com/
r/1k81XSBsJS

7. 1. Based on Approach
•Qualitative Risk Analysis
•Uses descriptive scales (e.g.,
low, medium, high)
•Relies on expert judgment,
experience, and scenarios
•Useful when data is limited
•Quantitative Risk Analysis
•Uses numerical values,
probabilities, and statistical
models
•Involves data analysis,
simulations (e.g., Monte Carlo),
and calculations
•Provides more precise estimates
of risk

11. risk assessment
Objective of risk assessment
•វាយវនមសៃ និងពិភាកម្ាអំពីហានិភ័យននស្រពឹវតិការណ៍ដ លមសិនចង់បាន
ដ លដកម្ើវដ ើង និងវិធានការដ លអាចដ្ ើដៅបានដ ើមសបីកាវ់បនាយវា
•ផតល់វិ្ីស្ថស្រ្តដបបវិទ្យាស្ថស្រ្ត រចនា្មសព័នធ និង្មសដេវុផល ចំដពាោះ
ំដណើរការ
•កាវ់បនាយហានិភ័យ (ការលុបបំបាវ់ ឬកាវ់បនាយដ លអាចដកម្ើវមាន
•ចងស្រកម្ងជាឯកម្ស្ថរ ំដណើរការ/វមាៃភាព និងស្របាកម្ ៏ចា្់

12. risk assessment
Objective of risk assessment
•Assess and discuss the risk of an undesirable event happen
and the possible measures to attenuate it
•Give a scientific, structured and logical approach to the
process
•Reduce the risk (possible elimination or mitigation
•Document the process/ Transparency

13. និយមសន័យកម្នងចាប់ ្ុវវាិភាពមសហ
ូ
បអាហារ

14. ការវាយវំនលហានិភ័យ (Risk Assessment)

15. Pinf is the probability of
infection, d is the dose
ingested
α and β are the
parameters of
Salmonella in dose-
response (Tenius, 2010)

16. 2.1. ការកម្ំណវ់អវត្ញ្ញា ណដស្រោោះថ្ននកម្់(Hazard identification
and prioritization)
•គឺជាវិ្ីមសួយដ ើមសបីកម្ំណវ់អវត្ញ្ញាណភានកម្់ងារជ្ីវស្ថស្រ្ត គីមសី និងរូបស្ថស្រ្តដ លមាន្មសវាភាពបងកផលប ោះ
ពាល់ ល់្ុខភាពដ លអាចមានដៅកម្ន
ុ
ងអាហារ ឬស្រកម្ុមសអាហារជាកម្់លាកម្់ណាមសួយ ដស្រោោះថ្ននកម្់អវិ្ុខុមស
ស្របាណដ លអាចដកម្ើវមានរួមសមាន បាកម្់ដវរី ជាវិពុល វីរុ្និងបា រ ្ុីវ (CAC/GL-30, 1999)
•វាជាដផនកម្មសួយ ៏្ំខាន់នន ំដណើរការដ លដស្របើដ ើមសបីវាយវនមសៃផលប ោះពាល់អវិជ្ជមានមសួយចំនួនដ លអាចមាន
្កាតនុពលបងកដស្រោោះថ្ននកម្់ ល់្ុខភាព ដេើយអាចស្រវូវបានយកម្គំរូវិភាគតាមសបរិមាណឬគុណភាព (Sperber,
2001)
•្មា្ធាវុ ននការកម្ំណវ់អវត្ញ្ញាណដស្រោោះថ្ននកម្់គឺអស្រតាដស្របវា ង់ននអវិ្ុខុមសស្របាណបងកជ្ំងឺ ស្របភពននធាវុ
បងកជ្ំងឺ ផៃ
ូ
វបញ្ជ
ូ
ន អស្រតារ្់រនមានជ្ីវិវននភានកម្់ងារបងកជ្ំងឺកម្ន
ុ
ងអាហារ លទ្យធផល្ុខភាពមសិនលអដ លបណាតលមស
កម្ពីការឆ្ៃងដមសដរគ និងបនទ
ុ
កម្ស្របជាជ្នននជ្ំងឺ (Pérez-Rodríguez et al., 2014; Possas et al., 2020).

17. 2.1 Hazard identification and prioritisation
•Hazard identification is a way to identify biological, chemical and physical agents
capable of causing adverse health effects that may be present in a particular food
or group of foods. Potential microbial hazards include bacteria and their toxins,
viruses and parasites.
•Typical components of hazard identification are the prevalence of pathogenic
microorganisms, the sources of pathogens, transmission routes, the survival rate of
pathogens in foods, the adverse health outcomes resulting from infection and the
population burden of disease (Pérez-Rodríguez et al., 2014; Possas et al., 2020).

19. Class activities 3- Hazard Identification៖ ចូររកម្
Chemical Food Hazard
19
Hazard ដ លបងតដស្រោោះថ្ននកម្់កម្ន
ុ
ងចំណីអាហារ
ដចកម្ជា ៤ ស្រកម្ុមស
1.Chemical Hazard
•រកម្ដ្ត ោះ Hazard ដេើយនឹងជ្ំងឺដ លបងករ
ដោយស្ថរធាវុគីមសីដនាោះ?
•្ដងេបពី វិ្ីស្ថស្រ្ត
•ដោលបំណង
•ភាពចំបាច់
•អវាបទ្យស្រស្ថវស្រជាវ

20. Class activities 3- Hazard Identification៖ ចូររកម្
Chemical Food Hazard
20
Hazard ដ លបងតដស្រោោះថ្ននកម្់កម្ន
ុ
ងចំណីអាហារ
ដចកម្ជា ៤ ស្រកម្ុមស
1.Biological Hazard
•រកម្ដ្ត ោះ Hazard ដេើយនឹងជ្ំងឺដ លបងករ
ដោយស្ថរធាវុដោយមសីស្រកម្ុបដនាោះ?
•្ដងេបពី វិ្ីស្ថស្រ្ត
•ដោលបំណង
•ភាពចំបាច់
•អវាបទ្យស្រស្ថវស្រជាវ

21. Bacterial Hazards
•Brucella spp. (cattle, swine)
•Campylobacter spp. (C. jejuni, C. coli, C. lari)
•Clostridioides difficile (smoked/dried freshwater fish)
•Escherichia coli (hygiene indicator; high prevalence in poultry, pork,
fishery products)
•Salmonella spp. (poultry, pork, fish, cutting boards; including
Salmonella enterica)
•Staphylococcus aureus (poultry, pork, cutting boards)
•Vibrio spp. (V. parahaemolyticus, V. vulnificus, V. cholerae, V.
alginolyticus) in fish products
•Listeria
21

22. Viral Hazards
22
•Astrovirus (bats)
•Nipah virus (bats; spillover risk noted)
•Hepatitis E virus (pigs, pork products)
•Hepatitis A:
•Norovirus:
•Rotavirus:

23. Parasitic Hazards
•Fasciola gigantica / Fasciola spp. (cattle, buffalo)
•Sarcocystis spp. (S. heydorni, S. cruzi) in cattle/buffalo
•Gnathostoma spinigerum (edible frogs; also detected in fish)
23

24. Parasitic Hazards
Pig and pork parasites:
•Taenia spp. (T. solium)
•Trichinella spp.
•Blastocystis spp.
•Ascaris spp.
•Entamoeba spp.
•Balantidium coli
•Trichuris suis
•Oesophagostomum spp.
•Metastrongylus spp.
•Gnathostoma doloresi
•Capillaria spp.
•Ascarops spp.
Fish and fishery product parasites:
•Opisthorchis viverrini
•Haplorchis yokogawai
•Haplorchis pumilio
•Pygidiopsis cambodiensis n. sp.
•Stellantchasmus falcatus
•Procerovum sp.
•Centrocestus formosanus
•Echinostoma mekongi
•Angiostrongylus cantonensis
24

25. Biotoxins Identified
•Found in fish and crab samples from lakes, seashores, and wet
markets in Phnom Penh, Kandal, Kratie, and Sihanoukville.
•Detection methods: High-Performance Liquid Chromatography
(HPLC) and Liquid Chromatography–Mass Spectrometry (LC-MS).
25

26. ការវាយវំនលហានិភ័យដបប គុណភាព និងបរិមាណ

27. 2.2. ការកម្ំណវ់លកម្េណៈដស្រោោះថ្ននកម្់ (Hazard Characterisation)
•ដៅដពលដ លដស្រោោះថ្នន កម្់/ដមសដរគស្រវូវបានរកម្ដ ើញ ព័វ៌មានអំពីលកម្េណៈមសូលោានននដស្រោោះថ្នន កម្់ចំបាច់ស្រវូវស្របមសូល
(Crawley & Tyler, 2003)
•ការកម្ំណវ់លកម្េណៈដស្រោោះថ្ននកម្់ពាកម្់ព័នធនឹងការវាយវនមសៃគុណភាព និង/ឬបរិមាណនន្មសតជាវិននផលប ោះពាល់អវិជ្ជមាន
ដ លទាកម្់ទ្យងនឹងភានកម្់ងារជ្ីវស្ថស្រ្តដ លអាចមានដៅកម្ន
ុ
ងអាហារ (CAC/GL-30, 1999; Perez-Rodriguez, 2020).
•វាជាជ្ំហានបនតបនាទប់ននការវាយវនមសៃ ូចជាការ្ដស្រមសចចិវតដលើវិ្ីស្ថស្រ្តកម្ំណវ់អវត្ញ្ញាណធាវុបងកជ្ំងឺ
•លកម្េណៈននដស្រោោះថ្ននកម្់នឹងដស្របស្របួលអាស្រ្័យដលើស្របដភទ្យននអវិ្ុខុមសស្របាណ ដេើយនឹងមានការរួមសបញ្ច
ូ
លោនននលកម្េណៈ
ដ្ដនទ្យិកម្ និងលកម្េណៈរូបស្ថស្រ្ត (Lammerding & Fazil, 2000; Possas et al., 2020).
•ចំដពាោះបាកម្់ដវរីបងកជ្ំងឺកម្ន
ុ
ងអាហារ លកម្េណៈភានកម្់ងារបងកដរគទ្យូដៅ ពាកម្់ព័នធនឹងវិ្ីស្ថស្រ្តកម្ន
ុ
ងការរកម្មសីស្រកម្ុបដ លមានឥទ្យធិ
ពលអវិជ្ជមានដលើអាហារ និង្ុខភាពមសនុ្ស (CAC/GL-30, 1999).

28. 2.2. Hazard Characterisation
•Once a hazard/pathogen has been identified, information on the basic characteristics of the hazard is gathered
(Crawley & Tyler, 2003).
•Hazard characterisation involves qualitative and/or quantitative evaluation of the nature of the adverse effects
associated with biological agents that may be present in food (CAC/GL-30, 1999; Perez-Rodriguez, 2020).
• This aids in subsequent steps of the assessment, such as deciding on the method for identifying the pathogen.
•The characteristics of a hazard will vary depending on the type of microorganism and will comprise a combination
of genotypic and phenotypic characteristics (Lammerding & Fazil, 2000; Possas et al., 2020).
• For bacterial foodborne pathogens, the general pathogen characteristics of interest may include methods for
detecting microorganisms that have a negative effect on food and human health (CAC/GL-30, 1999).

31. Dose respond

32. 2.3. វាយវំនលផលប ោះពាល់ (Exposure assessment)
•ការវាយវនមសៃដលើការប ោះពាល់មានដោលបំណង្ិកម្ាពីជ្ំហាន/្កម្មសតភាព/ឥរិយាបទ្យ ៏្ំខាន់ចមសបង ដ លអាច
បណាតលឱ្យបាកម្់ដវរីឆ្ៃងដមសដរគឆ្ៃងតាមសដខស្ងា កម្់ពីកម្្ិោានដៅអនកម្បរិដភាគ (CAC/GL-30, 1999)
•ការដស្របើស្របា្់គំរូកម្ន
ុ
ងការវាយវនមសៃការប ោះពាល់្ស្រមាប់ QMRA ជ្ួនកាលអាចមានភាព្ត
ុ
ស្រគស្ថតញ ដោយស្ថរ
ដោលបំណងដ ើមសបីវាយវនមសៃស្ថានភាព្ុខភាពស្ថធារណៈទាកម្់ទ្យងនឹងដស្រោោះថ្ននកម្់ជ្ីវស្ថស្រ្តជាកម្់លាកម្់ដៅកម្ន
ុ
ង
ផលិវផលអាហារ (Oscar, 2021b)
•ការពិដស្ថ្ន៍ជា្មសតតាស្រវូវបានដរៀបចំដ ើងដ ើមសបីវាយវនមសៃការដឆ្ៃើយវបកម្ន
ុ
ងកម្ស្រមសិវខព្់ដ លទាកម្់ទ្យងោន (ដ ន
កម្ំណវ់ននការរកម្ដ ើញអវិ្ុខុមសស្របាណ និងចំនួនកម្ំណវ់ននឯកម្តាពិដស្ថ្ន៍) ដេើយភាពញឹកម្ញាប់ននការឆ្ៃង
ឬជ្ំងឺវិចវួចមសិនអាចវាយវនមសៃបានចា្់លា្់ដនាោះដទ្យ
•ភានកម្់ងារបងកដរគមសួយចំនួនអាចឆ្ៃង ល់មសនុ្ស ដ លប ោះពាល់្ុខភាពដទាោះបីមានដវមសួយប ុដណាោ ោះ
(Bernstein et al., 2020; Oscar, 2004, 2021b).

33. 2.3. Exposure assessment
•Exposure assessment aims to study the primary critical step/activities/ behaviour
that could cause bacteria to cross-contaminate along the chain from farm to fork
(CAC/GL-30, 1999).
•Use of models in exposure assessments for QMRA is sometimes complex, due to
the aim to evaluate public health status regarding a specific biological hazard in a
food product (Oscar, 2021b).
•Experiments are usually designed to assess response at relatively high doses
(microbial detection limit and a limited number of experimental units), and a
minor frequency of infection or illness cannot be precisely assessed.
•Some pathogens can infect humans exposed to only a single dose (Bernstein et al.,
2020; Oscar, 2004, 2021b).

35. Example of Exposure Assessment

36. 3. Exposure assessment
•Human exposure pathways for
Salmonella, estimates the quantities
(dose) consumed.
•The frequency of meat consumption,
the quantity of salad consumed
Develop QMRA model
•Handling practices at household
level, and define potential scenarios
of risk exposure
Household survey or
Participatory (Focus
group discussion-
FGD)
Market survey in
25 cities and
provinces
•The concentration of Salmonella in
chicken and pork sold in markets.
Salmonella
cross-
contamination
experiment
36

37. 3. Exposure assessment
Develop QMRA model
Market survey in
25 cities and
provinces
•The concentration of Salmonella in
chicken and pork sold in markets.
Analyses Chicken Pork
No. of Salmonella positive
samples (%) (n=201)
84 (41.7) 85 (42.3)
Average MNP/g 16.7 17.3
Nation wide survey in 25 cities and provinces in Cambodia
37

38. 3. Exposure assessment
Develop QMRA model
•Handling practices at household level,
and define potential scenarios of risk
exposure
Salmonella
cross-
contamination
experiment
38

39. •Cross-contamination pathways:
Experiment of chicken salad preparation and cooking
Develop QMRA model
Washing
Raw
chicken
inoculated
Raw
chicken
washed
Boiled
chicken
HandsKnife
Cutting board
Raw
chicken
Hand
s
KnifeCutting board
Boiling
15 min
Washing
twice
Chicken salad
Chicken salad
Slicing
Scen-
2
Hands
Chicken salad
Chicken salad
Raw
Vegetable
Prepared vegetable
Mixing
Collecting samples
Hands
Hand
s
KnifeCutting board
Washing vegetable before
washing chicken
Washing vegetable after
washing chicken
Washing
twice
KnifeUsed the same cutting board and knife
3. Exposure assessment
39

40. 40
Chea, Rortana, et al. "Experimental cross-contamination of chicken salad with Salmonella enterica serovars
Typhimurium and London during food preparation in Cambodian households."PLoS One17.8 (2022): e0270425.

41. 3. Exposure assessment
Develop QMRA model
•Handling practices at household
level, and define potential scenarios
of risk exposure
Salmonella
cross-
contamination
experimentScenario 1Scenario 2Scenario 3Scenario 4Total
RawCK 8 7 8 9 32
Vegetable - - 1 1 2
CuttingBoard 5 - 7 - 12
Hands 3 1 3 1 8
Knife 3 - 6 - 9
Salad 7 1 2 0 10
Total 26 9 27 11 73
Number of Salmonella positive samples (n=9)
Sample types
41

42. 2.4. លកម្េណៈហានិភ័យ Risk characterisation
•លកម្េណៈហានិភ័យ ជាជ្ំហានចុងដស្រកាយនន QMRA គឺជាមសូលោានស្រគឹោះជ្ីវស្ថស្រ្ត្ស្រមាប់គំរូដឆ្ៃើយវបកម្ស្រមសិវដមសដរគបងកដស្រោោះ
ថ្ននកម្់ និងស្រគប ណតប់ដលើ្មា្ធាវុ្ំខាន់ៗនន ំដណើរការជ្ំងឺ៖ ការប ោះពាល់ ការឆ្ៃង ជ្ំងឺ និងផលវិបាកម្ (ការជា្ោះដ្បើយ
បនតបនាទ ប់ ឬការស្ថៃ ប់) (CAC/GL-30, 1999)
•លទ្យធផលហានិភ័យដកម្ើវដចញពីអនតរកម្មសតរវាងធាវុបងកជ្ំងឺ មាច្់ និងកម្ស្រមសឹវអាហារ ផតល់អស្រតាស្របចំនងៃ ល់អស្រតាដកម្ើវជ្ំងឺស្របចំ
ឆ្នំដោយស្ថរធាវុបងកជ្ំងឺដ លកម្ំពុង្ិកម្ា (Perez-Rodriguez, 2020).
•តាមសន័យគណិវវិទ្យា វាដវងដវមានស្របូបាប ីលីដវមសិន្ូនយជានិចចននការឆ្ៃង ឬដកម្ើវជ្ំងឺដៅដពលដ លមាច ្់បានប ោះពាល់ដៅ
នឹងភានកម្់ងារបងកជ្ំងឺឆ្ៃង (CAC/GL-30, 1999; Wagner & Hensel, 2011; WHO,2009).
•ការវាយវនមសៃហានិភ័យ Stochastic ពាកម្់ព័នធនឹងការគណនាជាដស្រចើនកម្ន
ុ
ងការដ្ ើគំរូពីស្របូបាប ីលីដវននជ្ំងឺដោយដស្របើបា រ ដមស ស្រវ
ដផសងៗោន រួមសទាំងការដតតវដលើដស្រោោះថ្ននកម្់ ដស្របកម្ង់ និងបរិមាណននការទ្យទ្យួលទាន ស្របូបាប ីលីដវននការចមសៃងដរគ ្ីវុណហភាព
ផទ
ុ
កម្ និងដពលដវលារេូវ ល់ការបរិដភាគ (Makita et al., 2019).

43. 2.4. Risk characterisation
•Risk characterisation, the final step of QMRA, is the biological foundation for dose-response
models and covers major components of the disease process: exposure, infection, illness and
consequences (recovery, sequelae or death) (CAC/GL-30, 1999).
•The risk outcome results from the interactions between the pathogen, the host and the food matrix,
giving the daily incidence to annual incidence of disease due to the pathogen under study (Perez-
Rodriguez, 2020).
•Mathematically, there is always a non-zero probability of infection or illness when a host is
exposed to an infectious pathogenic organism (CAC/GL-30, 1999; Wagner & Hensel, 2011; WHO,
•2009).
•Stochastic risk assessment involves a variety of calculations in modelling the probability of illness
using different parameters, including the concentration of the hazard, frequency and amount of
ingestion, probability of contamination, storage temperature and the time until consumption
(Makita et al., 2019).

45. Class activities 4: Read and find consequence
45
រកម្ Hazard និង Consequence កម្ន
ុ
ងចំណីអាហារ
ដចកម្ជា ៤ ស្រកម្ុមស
1.Diarrheal disease agents
2.Invasive infectious disease agents
3.Chemicals and toxins
4.Helminths
•រកម្ដ្ត ោះ Hazard ដ លបងកជ្ំងឺពុលអាហារ ូចខាងដស្រកាមស?
•រកម្ថ្នដវើ Hazard មសួយណាដ លបងកផលប ោះពាល់ ឬដស្រោោះថ្នន កម្់
ខាៃំងជាងដគ ឬមានអនកម្រងដស្រោោះដស្រចើន?

46. Group discussion (Divide into 4 groups)
•Group 1, work on Food Safety
Law and what Risk Analysis
Apply on food safety from
Animal Source Food
•Group 2: work on the trade
and animal (example on 1
animal) what are the
compliant that used for
export/import animal
according to WOAH.
•Group 3: Risk assessment in
WHO/FAO codex how it work?
•Group 4: Risk analysis in
World Trade Organization
(WTO), how they work?
•Each group discussion
and find references
•Pick up 1 example
•Prepare a presentation
slide (not exceed 10
slides)
•Present to the class

47. ការវាយវំនលហានិភ័យដបប គុណភាព និងបរិមាណ

48. Risk Analysis Quiz 4: QMRA Model from FAO
WHO
•https://forms.office.com/r
/gxBQ8Ddcb3

49. References
•Codex Alimentarius Commission (CAC). (1999). Principles and
Guidelines for the Conduct of Microbiological Risk Assessment. Rome:
Codex Alimentarius Commission.
•Addressing avian influenza (H7N9) – Qualitative Risk Assessment
Update. FAO EMPRES
•http://www.oie.int/international-standard-setting/terrestrial-
code/access-online/
•Rortana, C., Dang-Xuan, S., Nguyen-Viet, H., Unger, F., Lindahl, J. F.,
Tum, S., ... & Boqvist, S. (2022). Quantitative risk assessment of
salmonellosis in Cambodian consumers through chicken and pork
salad consumption.Frontiers in sustainable food systems,6, 1059235.

50. Research Related to Risk Analysis
•Rortana, C. (2023). Foodborne bacteria in the Cambodian meat value chain: emphasis on the risk
of Salmonella in chicken and pork from traditional markets to household consumption.Acta
Universitatis Agriculturae Sueciae, (2023: 8).
•Rortana, C et al. (2022, December 22). Quantitative risk assessment of salmonellosis in
Cambodian consumers through chicken and pork salad consumption. Frontiers in Sustainable Food
Systems, 6. https://doi.org/10.3389/fsufs.2022.1059235
•Rortana C. et al, (2022) Experimental cross-contamination of chicken salad withSalmonella
entericaserovars Typhimurium and London during food preparation in Cambodian households.
PLoS ONE 17(8): e0270425. https://doi.org/10.1371/journal.pone.0270425
•Rortana C.et al. (2021). Prevalence of Salmonella spp. and Staphylococcus aureus in chicken
meat and pork from Cambodian Markets."Pathogens10, no. 5: 556.

51. Read more
•Heng Theng, Rortana Chea, et al., 2023. Food safety interventions: changes
of knowledge, attitude, and practices of pork retailers in traditional Cambodia
market. Kasetsart Journal of Veterinarians. 0125-5169.
•Hung Nguyen-Viet et al., 2021. Pork and poultry safety in traditional markets
in Cambodia: Understanding complexities and scaling up good interventions.
ILRI Policy Brief. Nairobi, Kenya: ILRI. https://hdl.handle.net/10568/114472.
•San, Shwe Phue, et al. "Chemical hazards in products of animal origin in
Cambodia from 2000 to 2023: A systematic review and meta-
analysis."International Journal of Environmental Research and Public
Health22.8 (2025): 1299.
•San, Shwe Phue, et al. "Biological hazards and indicators found in products
of animal origin in Cambodia from 2000 to 2022: A systematic
review."International Journal of Environmental Research and Public
Health21.12 (2024): 1621.

52. កម្ិចចការស្រកម្ុមស (១ស្រកម្ុមស ចំនួន ៥នាកម្់)
•Read the paper and
answer the quiz
https://forms.office.com/r/pbVhLkwsar

53. Next is: correct answer of the
quiz

54. Education is the power to think
clearly
Ref: MoEYS, Cambodia