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