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Pests and PesticidesPests and PesticidesChapter 7
Pests and EcosystemsPests and Ecosystems
Pests are unwanted plants (weeds) or animals (vectors)
The most common type of vectors are insects (arthropods) and rodents
Overpopulation, poverty, and lack of sanitation provide opportunities for vector-borne diseases
Global warming and resistance make control of disease-carrying vectors difficult
PesticidesPesticides
Include:◦Insecticides◦Fungicides◦Herbicides◦Ascaricides◦Rodenticides
Five principal classes of pesticides:◦Organochlorines◦Organophosphates◦Carbamates◦Pyrethroids◦Phenoxy herbicides
Pesticide ControversyPesticide Controversy
They have harmful effects on birds, fish, animals, and humans
There are long-term effects with repeated exposure in plants that manufacture the pesticides and those who use them◦Farm workers◦Aerial crop-dusting pilots◦Professional pest control workers
Pesticides are especially harmful to children
Alternatives to PesticidesAlternatives to Pesticides
Plants that are toxic to insects but are not toxic to animals (e.g., chyrsanthemum)
Solution of dishwashing soap to water for small insects like aphids
Natural predators can be used (e.g., mosquitofish)
Integrated pest management (IPM) uses the most economical and least hazardous means to control pests
Human Risk from PesticidesHuman Risk from Pesticides
Pesticides can be inhaled, ingested, or absorbed
The most harmful are organophosphates, which are toxic to the nervous system
Acute poisoning calls for quick action◦Determine the type and how much◦Call Poison Control and follow directions
Chronic health problems occur with repeated exposure over time
Reproductive problems occur when exposed to endocrine disrupters
Many are carcinogenic (lymphoma in farmers)
Pesticides on FoodPesticides on Food
An amendment to FIFRA, the Food Quality Protection Act (1996) provided for the EPA to set allowable pesticide residue levels for food
The risk to children is the greatestThe EPA also looks at
◦potential effects of endocrine disruptors, ◦potential teratogenic effects, ◦aggregate risk from all sources and routes of
exposure, ◦as well as cumulative risks due to exposure
Wash your produce!Wash your produce!
Foods with the highest toxicity indexes for pesticides include:◦Fresh peaches◦Frozen and fresh winter squash◦Apples◦Grapes◦Spinach◦Pears◦Green beans◦Broccoli◦Orange juice◦Bananas◦Corn
RadiationRadiation
Chapter 12
Exposure to RadiationExposure to Radiation
All plants, animals, and humans are constantly exposed
Natural and artificial sourcesThe average U.S. citizen receives 350
millirems of radiation per year
Natural Sources of RadioactivityNatural Sources of Radioactivity
80% of exposure comes from natural sources
Natural sources include◦UV light from the sun◦Radon from the soil ◦Uranium in rocks and soil◦55% of the exposure is from radon gas
Artificial Sources of RadioactivityArtificial Sources of Radioactivity
Man-made sources◦Communications devices (TVs, radios,
computers, cell phones)◦Microwaves◦X-rays and other medical devices
About 18–20% of radiation exposure comes from these sources
Who Monitors Radioactivity Who Monitors Radioactivity Exposure?Exposure?
In hospitals ◦A radiologist
In nuclear facilities◦Health physicist
In public health departments◦An environmental health specialist
Cell Damage from RadioactivityCell Damage from Radioactivity
DNA is damaged in dividing cells◦Epidermal skin, bone marrow, RBCs, and sperm
Damage to lipoprotein structures in the nuclear cell membrane◦Ova and lymphocytes
The most harm comes to developing fetuses◦Genetic effects◦Mental retardation
Cancer RiskCancer Risk
The biggest concern is the risk of developing cancer
Effects of ionizing radiation (including overexposure to diagnostic radiation) include a higher risk of ◦Lung cancer◦Skin cancer◦Breast cancer◦Thyroid cancer ◦Leukemia
To Reduce Radiation ExposureTo Reduce Radiation Exposure
Increase the distance from a radiation source (UV sunlight, radon, etc.)
Wear protective shields or clothingDispose of contaminated objects with the
help of a radiological health professional or health physicist
Limit the time exposed to x-rays or radiation treatments
Use a HEPA filter in furnaces and air conditioning units
Health Risks of UV LightHealth Risks of UV Light
UV-A penetrates the skin causing photoaging damage
UV-B light causes tanning and sunburn (erythema) and damages the immune system
UV-C light can damage DNA (melanoma) and other molecules
Direct UV exposure can cause blindness (photokeratitis, “welder’s flash” or “snow blindness”) and cataracts
More ResearchMore Research
The most susceptible organs are the eyes and brain
Some research showing increased risk of breast cancer for radio and telegraph operators
Reproductive effects?◦Higher miscarraiges and birth defects from
pregnant women using monitors 20 hours per week or longer during the first trimester
◦Some wonder if the heat from laptops will affect sperm
Food Safety ConcernsFood Safety ConcernsChapter 13
Food Safety ConcernsFood Safety Concerns
Things important to food safety:◦Quality of foodSanitation practices of food handlers
◦Shelf lifePreservatives
◦Presence of contaminantsAdulterantsFood-borne illnesses
◦Preparation◦Storage
Federal Laws Protecting Food Federal Laws Protecting Food QualityQuality
1906 Pure Food and Drug Act◦Inspection of food and drugs for adulteration
and mislabeling1938 Food, Drug, and Cosmetic Act
◦Proof of safety before a drug is released to consumers
◦Amendments:Pesticide Amendment of 1954Food Additives Amendment of 1958Color Additives Amendment of 1960
Food-Borne IllnessesFood-Borne Illnesses
Accounts for 76 million illnesses, 325,000 hospitalizations, and 52,000 deaths nationally per year
Sources:◦Fecal contamination◦Improperly prepared foods◦Infected food handlers
Prevention of Food-Borne Prevention of Food-Borne IllnessesIllnesses
PasteurizationFood inspection for meat and produce
itemsFood irradiationFood recallsProper cooking techniques
◦Heating meats and foods to 165oFProper food storageProper sanitationRestaurant inspections
Food IrradiationFood Irradiation
Also known as “cold pastuerization”Uses extremely short wave lengths of
radiationThe electron beams penetrate food The molecular structure of the food is
disruptedAccording to IFIC the food is safe because
it never touches the energy source
Concerns About IrradiationConcerns About Irradiation
Changes in glycemic index of foodsDestruction of vitamins and antioxidantsLoss of nutrients due to longer food
storage
What Is “Organic”?What Is “Organic”?
Let the buyer bewareSome organic products are not
pasteurizedMany have a short shelf lifeBulk foods may be contaminated with
hair, feces, dirt, and other particlesSome food contaminants are considered
“acceptable”If the food is imported from foreign
countries, it may contain pesticides
Questionable IngredientsQuestionable Ingredients
Food substitutes: cyclamates, saccharin, aspartame, olestra
Cured meats containing nitrosaminesPorous foods such as peaches,
strawberries, raspberries because of the ability to absorb more pesticides than other foods
Hormones in MeatHormones in Meat
In the 1970s diethylstilbestrol (DES) was given to chickens and cattle◦The effects of DES on female offspring of
women who used it caused concernOther hormones used include estradiol,
testosterone, progesterone, trenbolone acetate, and zeranol
Tissue residue levels are monitored before the FDA approves them for sale
Environmentalists have found effects on wildlife from manure of animals given hormones
Genetically Engineered FoodsGenetically Engineered Foods
Considered ethically in the same way as cross-breeding or producing hybrid seeds
The DNA from one plant is introduced to another plant
Advantages◦Less pesticides and herbicides are needed◦More nutrient dense foods
70–75% of processed foods in the U.S. contain genetically engineered ingredients.
Concerns About Genetically Concerns About Genetically Engineered FoodsEngineered Foods
Those with food allergies may be unaware that the foods have been genetically altered
The hardier plants may pollinate and reproduce as a “super weed” causing bioinvasion problems
Restaurant InspectionsRestaurant Inspections
Local health departments inspect◦Public institutes (hospitals and schools)◦Restaurants
Restaurant owners are given time to comply with regulations
Some local health departments post “ratings” of food establishments for consumer awareness
What Inspectors Look ForWhat Inspectors Look For
Structure of the facility
Water supplyEquipment and
suppliesProper temperature
for food storageProper temperature
for sanitizing utensils, silverware, glassware, and dishes
Waste management techniques
Approved food sources
Food serving practices
Hand washingDamage of
glassware and dishes
Housing and Indoor Housing and Indoor EnvironmentsEnvironments
Chapter 15
Air Pollution ProblemsAir Pollution Problems
Outdoor SourcesAutomobile
emissionsIndustrial emissionsGlobal warmingThinning of the
ozone layer
Indoor SourcesBuilding materialsSmokersCleaning chemicals
and solventsPesticidesVolatile organic
compounds (VOCs)Mold, mildew, dust,
pollenRadon
Where to Live?Where to Live?
Geographical considerationsClimateEmploymentLow crime ratesCommunity and government services
◦Drinking water and solid waste disposal◦Public transportation◦Parks and recreation
Basic Housing NeedsBasic Housing Needs
Supportive structure in compliance with building codes and public health codes.
Soundproofing and insulationAdequate spaceAdequate lightingAdequate temperature and humidityAdequate ventilationGood sanitation
Reducing Indoor Air PollutionReducing Indoor Air Pollution
Do not permit smoking indoorsRemove plants and animalsImprove indoor ventilationDust weeklySubstitute nontoxic cleaners for toxic onesInstall ceiling fansConsider air cleaning devices
Improving Your ImmunityImproving Your Immunity
Consume foods high in vitamins B, C, and D, protein, and minerals such as calcium, magnesium, copper, and chromium
Increase intake of antioxidants (bright-colored fruits and vegetables, green tea)
Reduce the consumption of fat (stores toxic substances)
Indoor Air PollutionIndoor Air Pollution
90% of time is spent indoorsOne of the top five environmental risksIndoor pollution can be 2–100 times
higher than outdoor pollutionAccounts for the majority of lung cancer
deathsSince the 1970s buildings have been built
airtight to conserve energyHeadaches, allergies, depression, and
chronic respiratory problems are indicators of indoor pollution