Pesticides and Health Flashcards
Examples of pests
1 Insects 2 Weeds 3 Fungi 4 Bacteria 5 Viruses 6 Mice
Pesticide
Any substance or mixture of substances intended for preventing, destroying or controlling any pests including vectors of human or animal disease
Pests
Living organisms that are not wanted/can cause damage to crops, humans or the environment
Where are pesticides used?
1 Forests to control insects and under-story vegetation
2 Landscapes, parks, and recreational areas to control weeds, insects, and disease pests
3 Along railroads and under electric wires to control vegetation
4 Houses, schools, and commercial and office buildings to control insects, rodents, and fungi
5 Boat hulls to control fouling organisms
6 Aquatic sites to control mosquitoes and weeds
7 Wood products to control wood-destroying organisms
8 Food preparation areas to control insects and rodents
9 Human skin to kill or repel insects
10 Household pets to control fleas and ticks
11 Livestock to control insects and other pests
Wood-destroying organisms
Termites
Pesticide exposure
1 Occupational settings 2 Environmental-occupational interface 3 Environmental settings 4 Accidental ingestion 5 Suicide/homicide
Agriculture jobs
1 Orchard thinner
2 Mixer loader
3 Flagger
4 Picker
Pesticide exposure: Occupational settings
1 Multiple industries
2 Variety of workers
Multiple industries
1 Agriculture
2 Emergency response
3 Maintenance
4 Transportation
Variety of workers
1 Applicators, field workers
2 Firefighters
3 Medical personnel
4 Flight attendants
Pesticide exposure: Environmental-Occupational Interface
1 Drift
2 Take-home
Off-target physical movement of pesticide through air
Drift
Contaminate clothing
Take-home
Pesticide containers brought home
Take-home
Pesticide exposure: Environmental settings
1 Use in schools 2 Lawn, garden use 3 Household cleaning 4 Home pesticide use 5 Residues in food
Agriculture pesticide applications
1 Aerial 2 Air blast sprayer 3 Enclosed cab 4 Boom sprayer 5 Backpack wand
Example of prescription pesticide that resembles oral medications
Lindane
Pesticide exposure: Accidental ingestion
1 Improper storage or mislabeling of container
2 Prescription pesticides resembling oral medications
Pesticide exposure: Suicide/homicide
1 Unknown substance
2 Secondary exposure
Concerns regarding pesticide use
1 Environmental
2 Health
POPS
Persistent organic pollutants
Environmental concerns
1 Persistence in the environment
2 Bio-concentration up the food chain
Health concerns
1 Acute effects
2 Chronic effects
Author of Silent Spring (1962)
Rachel Carson
Classification of pesticides
1 Types of pests
2 Chemical class
3 Toxicity
Hazard
Hazard = Exposure x Toxicity
How pesticides enter the body
Exposure
How poisonous the pesticide is
Toxicity
Relationship of toxicity and LD50
Inverse
Classification of pesticides according to types of pests
1 Insecticides 2 Fungicides 3 Herbicides 4 Rodenticides 5 Molluscides
Chemical class classification of pesticides
1 Insecticides
2 Herbicides
3 Fungicides
4 Rodenticides
Chemical class: Insectides
1 Organophosphorus 2 Carbamates 3 Organochlorines 4 Pyrethrins and pyrethroids 5 Arsenical compounds
Chemical class: Herbicides
1 Chlorophenoxy compounds 2 Pentachlorophenol 3 Nitrophenolic/cresolic compounds 4 Paraquat 5 Diquat 6 Arsenical compounds
Fungicides
1 Substituted benzenes
2 Thiocarbamates
3 Ethylene-bis-dithiocarbamates
4 Organo-metallic compounds
Rodenticides
1 Inorganics
2 Coumarins/indandiones
3 Convulsants
4 Cholecalciferol
Routes of exposure of pesticides
1 Dermal
2 Inhalation
3 Ingestion
Factors affecting absorption
1 Liposolubility of chemical
2 Molecular weight
3 Electronic structure and dissociation constant
4 Nature of carrier, dilution factor, polar vs non-polar
5 Temperature
T or F. Low mw pass through better
T
T or F. Highly ionized pesticides are less likely to be absorbed.
T
T or F. Polar pesticides penetrate better
F. Non-polar penetrate better
Exposure prevention (general)
1 Elimination 2 Substitution 3 Engineering 4 Administrative 5 PPE
Safe usage
1 Selection of type and concentration 2 Training and education 3 Personal protective equipment 4 Good work practices 5 Good personal hygiene 6 Administrative measures 7 Medical surveillance
Examples of administrative measures
1 Job rotation
2 Medical surveillance
3 Health education
Exposure prevention (specific)
1 Substitution of less hazardous agent 2 Follow label directions 3 Wear personal protective equipment 4 Apply pesticides during the right environmental conditions 5 Spray only when you need to 6 Import and licensing 7 Proper transport/storage/distribution 8 Proper usage 9 Research and development
Conventions
1 Basel convention
2 Rotterdam convention
Potential health effects of pesticides
1 Depend on the type of pesticide
2 Organophosphates and carbamates affect the nervous system
3 Others may irritate the skin or eyes
4 They can also affect hormones in the body
5 Some pesticides may be carcinogens
40 hazardous chemicals in Rotterdam Convention
1 25 pesticides
2 11 industrial chemicals
3 4 severely hazardous pesticide formulations
Rotterdam Convention (2004)
The Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals in International Trade on 10 September 1998 by a Conference of Plenipotentiaries in Rotterdam, the Netherlands
To regulate the control of export, import, and transit of hazardous wastes in accordance with the principles and provisions of the Basel Convention
The Hazardous Waste (Control of Export, Import, and Transit) Act and its Regulations (16 Mar 98)
Basel Convention
Convention on the Control of Transboundary Movements on Hazardous Wastes and their disposal (Basel Convention) in the control of export, import, and transport of hazardous wastes on 2 Jan 1996
Routes of organophosphates
1 Skin
2 Lung
3 Oral
Organophosphate poisoning
1 Cholinesterase (ChE) inhibitor
2 Narrow zone of toxic action
3 Water soluble
Example of organophosphates
Malathione
Examples of carbamates
1 Carbanyl
2 Aldicarb
3 Propoxur
4 Carbofuran
Routes of carbamates
1 Dermal
2 Respiratory
3 Oral
One of the best safety records
Pyrethrins and pyrethroids
Affects nervous system
Pyrethrins and pyrethroids
Pyrethrins and pyrethroids
1 Low concentrations
2 Low water solubility
3 Rapid metabolism
Symptoms of poisoning similar to organophosphates
Carbamates
Carbamates
1 Reversible cholinesterase inhibitor
2 Effects of day-to-day exposure do not accumulate
3 Blood AChE must be done within 4 hours of exposure to be useful
Organophosphate (AChEI) poisoning mechanism
1 Inhibition of acetylcholinesterase
2 Accumulation of acetylcholine (NT) at nerve synapses
3 Saturates ACh receptors
4 Overstimulates and later blocks further nerve impulse transmission
Onset of acute OP poisoning
Prompt but may be delayed up to 12 hours
Blood ChE in acute OP poisoning
Depressed by 50%
Severe intoxication of acute OP poisoning
Coma
Death
Symptoms of acute OP poisoning
1 Eyes: blurring, miosis (constriction)
2 Lungs: breathlessness, wheeze, pulmonary edema
3 GIT: nausea, vomiting, colic, diarrhea
4 CNS: giddiness, coma, fits, ataxia, paralysis, confusion, behavioral, weakness
Miosis: constriction
______: dilation
Mydriasis
Muscular stimulation of OP poisoning
Nicotinic effects
Nicotinic effects of OP poisoning
1 Muscle fasciculations, cramping, weakness, diaphragmatic failure
2 Autonomic nicotinic effects include hypertension, tachycardia, mydriasis, pallor
CNS effects of OP poisoning
Anxiety, emotional lability, restlessness, confusion, ataxia, tremors, seizures, coma
Stimulation of parasympathetic nervous system
Muscarinic effects
Muscarinic effects of OP poisoning
1 Salivation, lacrimation, urination, diarrhea, GI upset, emesis (SLUDGE)
2 Diaphoresis and diarrhea, urination, miosis, bradycardia, bronchospasm, bronchorrhea, emesis, excess lacrimation, salivation (DUMBELS)
Muscarinic effects by organ systems
1 Cardiovascular: bradycardia, hypotension
2 Respiratory: rhinorrhea, bronchorrhea, bronchospasm, cough, severe respiratory distress
3 Gastrointestinal: hypersalivation, nausea and vomiting, abdominal pain, diarrhea, fecal incontinence
4 Genitourinary: incontinence
5 Ocular: blurred vision, miosis
6 Glands: increased lacrimation, diaphoresis