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(37 cards)
Eutrophication, Causes and Consequences
Eutrophication: is the enrichment of water with Nitrogen and Phosphorus which causes the excessive growth of Algae and Phytoplankton
Occurs in lakes and slow-flowing rivers
Causes: Most commonly from Animal waste, fertiliser and sewage
Consequences:
1. Changes in water turbidity and O2 levels
2. Increase growth of algae
3. Precursors of Trihalomethanes - potential human carcinogens
4. Higher presence of dissolved organic substances and the presence ofmore particulates
5. Changes in dissolved oxygen
Health implications: Some algae, phytoplankton can produce Neurotoxins, Hepatotoxins, Cytotoxins, Endotoxing - very toxic to humans, animals
Differences in preventative and focal disinfection
Preventative: Mechanical cleaning is carried out after removing of manure, all organic matter and dirt from animal houses
Focal: Manure and organic matter must be disinfected before it is removed from the house
The aim of preventative disinfection
Elimination of the pathogens, decrease bacterial load and improving the hygiene in animal housings
Methods of rodent control
Complex of measures are directed at killing noxious, economically harmul rodents
Methods are:
1. Mechanical - traps (snap, catch, electronic)
2. Physical - water, sound
3. Biological - cats, dogs
4. Chemical - Rodenticides (Acute 6-24h, Subacute 3-6 days, Chronic 6-10 days)
Chlorine compounds, Mechanisms of action, Division, Properties, Using in %
Have good Bactericidal and Viricidal effects, effective against Gram + and Gram -, Viruses and Spores
Mechanism of action: Affects the Permeability of the outer cell membrane, Oxidation, Fat oxidation, changes in pH, destruction of Enzymatic system
Division into Inorganic and Organic substanses
1. Hypochlorites - Inorganic chlorine compounds
a) Sodium hypochlorite (NaOCl)
-Unstable (prepare fresh) - Liquid
-Active chlorine 15% Minimum
-Preventive: 2-3%
-Focal: 4-10%
b) Chlorinated lime (CaClOCl) - Calcium hypochlorite
-Unstable - Powder
-Active chlorine 33-36%, min 15%
-Preventive: 2-3%
-Focal: 5% (devitalise spores and mycobacteria)
- Chloramins - Organic chlorine compounds
a) Chloramine T
-Stable
-Active chlorine 25-30%
-Preventive: 2-3%
-Spores: 10%
b) Dikonyt
-Stable - Surace spray
-Active chlorine 55-60% (activation @ 50-60°C)
-Devitalise spores and mycobacteria
Aldehydes, Mechanism of action, Properties, Using in%
Highly effective broad spectrum disinfectants for bacteria, viruses, fungi, spores, mycobacteria
Mechanism of action: Have an effect on enzymatic systems, denaturation of proteins, disrupt nucleic acids
Properties: Unstable - Liquid, Vapour, Gas
-No disinectant effect under 15°C
-Spray form: 2% or 10%
-Aerosol: 25ml/m3 - 6 hours or overnight
-Vapour: Needs humidity of 70-90%
Use: 28-40%, 30%min
Alkaline formaldehyde (formalin) - Focal: 3% - Spores and Mycobacteria
Sanitation includes:
- Disinfection
- Insect control
- Rodent control
- Proper disposal of wastes
- Removal and treatment of excrements and cadavers
- Hygiene of the environment
Chemical parameters in drinking water, Limits and Impact on organim
Chemical parameters:
1. Indicator of potential faecal pollution: NH3, NO2, NO3
2. Substances affecting sensorial properties: Fe
3. Substances released from pipelines and during treatment of portable water
4. Disinectants and products of disinfection Cl2, THMs
5. Metals: Cd, Hg, Pb, As, Cu, Cr
6. Element desirable up to certain level: Ca, Mg, DO
Limits and impact:
1. Cadmium: 5μg/L
2. Mercury: 1 μg/L
3. Arsenic: 0.01 mg/L = consequence is intellectual impairment
4. Ammonia (NH4+): 0.5 mg/L = consequence is eutrophication
5. Nitrites (NO2): 0.1 mg/L = consequence is methemoglominemia
6. Nitrates (NO3): 50 mg/L adults, 15 mg/L youngs = consequence is methemoglobinemia
7. Chlorides (Cl-): 100mg/L
8. Iron (Fe+): 0.2 mg/L
9. Phosphates: 1.0 mg/L
10. Active chlorine (Cl2): 0.3 mg/L = consequence is risk off production of Reihalomethanes (THM)
11. Chemical oxygene demand: 3.0 mg/L
12. Water hardness Ca+, Mg+: 1.1-5 mmol/L
13. Dissolved oxygen (DO) > 50%
14. Conductivity: 125.0 mS/m
15. pH: 6.5-9.5 = consequence can be carcinogen and contribute to cardiovascular disease
Acids, Mechanism of action, Division, Properties, Using in %
Acids are the strongest disinectants. Effective against Gram +, Gram -, Viruses and Fungi
Mechanism of action:
1. Oxidation
2. Dehydration
3. Destruction of enzymatic system
4. Lower pH
5. Disrupt cellular wall permeability
6. Denaturation of proteins
Division into Inorganic and Organic acids
1. Inorganic acids
a)Hydrochloric acid (HCl) = Skin disinfectant, Spores
b)Sulphuric acid (H2SO4) = used with Cresol 1:3 for Focal, Tuberculosis and clostridium
c)Nitric acid (HNO3) = 0.3-0.5%, bacteria and spores in food industry
d)Phosphoric acid (H3PO4) = 1.5%-3%, for manure and soil
2.Organic acids
a)Peracetic acid = Active ingredient: 32-36% (15%min)
b)Lactic acid = Used to disinfect air, 5mg/m3
Definition of disinection
Means elimination of infectious and hygienically harmul microorganisms that may cause disease or affect adversely the health of animals and humans
Indicator of hazard in drinking water, Methods of determination, Limits, Impact on organism
- Enterobacteriaceae
-Method: Membrane filtration
-Specific agar: Endo agar @37°C for 24h - E. coli
-Method: Membrane filtration
-Specific agar: @43°C for 24h - Enterococci
-Method: Membrane filtration
-Specific agar: Slantez Blaney @37°C for 24h
Limits in mass supply: 0 in 100ml
Individual supply: 0 in 10ml
Control of disinfection effectivness
Bacteriological method is the most objective, indicator microorganisms are controlled before and after disinfection using sterile swabs
Continuous-preliminary disinfection must be preformed
Continually during shedding pathogenic agents from sick animals into environment, will be repeated during the disease process and continue with final focal disinfection
What is secondary poisoning (in rodent control) and how we prevent it?
Secondary poisonong is when one animal consumes a rodent poisoned. Prevention - pulsation method consist of placing low quantities of toxic baits, repeat palcing baits is practised for 6-7 days
Physical disinfection includes
- Heat
- Cold
- Desiccation
- Radiation
- UV
- Ozone
Hydroxides, Mechanism of action, Division, Properties, Using in %
Hydroxides are Alkali disinfectants, Corrosive and Active against Gram+ and Gram- bacteria and Viruses
Method of action:
1. Changes the pH
2. Destruction of cell structures
3. Hydrolyzation of proteins
Divisions
1. Sodium Hydroxide (NaOH)
-Lye, Caustic soda, Spray form
-Activation @70-80°C, Unstable in storage
-Gram-: 1%
-Gram+: 3-5%
-Viruses: 2-4%
-Spores: 5-10%
2. Potassium Hydroxide (KOH)
-Similar to NaOH, present in some cleaning products
3. Calcium Hydroxide (Ca(OH)2)
-Milk suspension: 20% on surfaces, non spore forming bacteria, bactericidal on Acid resistant mycobacteria
-CaO-lime: 3% on soil, slurry and manure, corrosive to zinc, aluminium and tin
4. Ammonium Hydroxide
-Used for Coccidia oocysts
Which all factors affect the effectiveness of disinfection
- Resistance of microorganisms
- Effect of disinfectant
- Character of the environment
- Temperature of disinfectant and of environment
- Concentration of solution
- Quantity of used disinfectant
- Exposure time
- Number of application of disinfectant solution
Definition of sanitation
Sanitation is a complex of measures which are directed to removal, inactivation or killing of the agents of infections in the external environment
Use of sanitation
Sanitation uses an antimicrobial measures on objects, surfaces or living tissue to reduce the number of disease-causing organisms to non-threatening levels
Chemical rodenticides, Division, Chatacterisation, Using
Aim to kill harmful rodents by use of bait materials similar to feed
Division:
1. Acute = rapid acting, death within 6-24h
-Alphachiloralose, Norbromide, Zinc phosphide, Aluminium phosphide, red squil
-HCl reaction in stomach produce toxic hydrogen phosphide
2. Sub-acute = death after 3-6 days
-Quintox, Calcitox, Slovtox
-Cause hypervitaminosis, death by heart attack due to calcium disturbances
3. Chronic = slow acting, death within 4-10 days
-Anticoagulants e.g. warfarin, brodifacoum, brimdialone
-Changes the blood ability to clot= bleeding to death
Focal disinfection means
Eradication of pathogens at the focus of inection, to interrupt disease transmission
Stages of disinfection in focal disinfection
- Preparatory works
- Disinection
- Mechanical cleaning
- Control of disinfection effectiveness
- Protocol
Methods used for mechanical cleaning include
- Mechanical methods
- Hot water under pressure
- Detergent (soda)
Up to 90% microorganisms are removed from the environment
Iodine compounds, Mechanism of action, Properties, Using in %
Used on skin, aqueous and alcoholic solutions that has Bactericidal and Virucidal effects
Mechanism of action:
1. Denaturation of proteins
2. Interferes with the enzymatic system of microorganisms
Use:
1. Iodonal A = 1.75% active iodine (12.5% phosphoric acid)
-Preventive: 2-4%
-Focal: 5-6%
2. Iodonal B = 1.66% active iodine
3. Iodonal M = 1.6% active iodine
-Treatment of udder: 2-4%
-Teat dipping: 20%
E.g. Betadine
