340 likes | 359 Views
Explore the use of biological control and chemical pesticides to manage pests, the risks involved, and the environmental impact of different types of pesticides. Learn about bioaccumulation, biomagnification, and the effects of pesticide contamination on food and water.
E N D
The burden of proof imposed on individuals, companies, and institutions should be to show that pollution options have been thoroughly examined, evaluated and used before lesser options are chosen. JOEL HIRSCHORN
PROTECTING FOOD RESOURCES: PEST MANAGEMENT (17) Pest: Any organism that interferes in some way with human welfare or activities _________________is a bioeffector-method of controlling pests (including insects, mites, weeds and plant diseases) using other living organisms. Spiders control populations of most pest species as part of the ____________________________. Ladybugsare voracious predators of aphids, and can be used in gardens to control pests. The risk involved in biological control: Attacking only the _____________________ ___________________________________ 2. Importing organism introduces a new _____________________ to the ecosystem. Biological control programs aim to reduce or eliminate populations of _________________________________________________________________
Biological Control in not enough: Chemical Warfare To speed up the process of biological control we use chemicals to repel or kill pest organisms as plants have done for millions of years. The geranium, for example, produces a unique chemical compound in its petals to defend itself from Japanese beetles. Within 30 minutes of ingestion the chemical paralyzes the herbivore. While the chemical usually wears off within a few hours, during this time the beetle is often consumed by its own predators. Biopesticides are certain types of pesticides derived from such living organisms or certain minerals. Although more beneficial for the environment, natural chemicals (Biopesticides ) are not _____________________________________________________________________________.
Types of pesticides Chemists have developed hundreds of synthetic chemicals (pesticides) that can kill or repel pests. Herbicide: kills weeds(agriculture) Fungicide: kills fungi(mold and mildew) Rodenticide: kills rodents(mice and rats) Insecticide: kills insects (agriculture) Nematicides: kills nematodes (roundworms) Piscicides: kills fish (unwanted species) Algaecides: kills algae (controls eutrophic blooms) Pesticides vary in their persistence: or _____________________________________________. 1. Persistent (hard) Pesticides: Composed of compounds that retain their toxicity for long periods of time. Ex: DDT 2. Reduced-risk (soft) pesticides. They are short-term and don’t harm or are far less harmful to the environment. Ex: soaps, oils, plant extracts.
Effects of Persistence Persistent substances are bioaccumulated and biomagnifed in the environment. Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when _______________________________ _____________________________________________________________________________ Most contaminants are stored in the _______________________of organisms. Biomagnification, is the increasing concentration of a substance, such as Mercury or DDT, in the ___________________________ _______________________________________.
For example, though mercury is only present in small amounts in seawater and is absorbed by algae. Bioaccumulation result in buildup of mercury in the algae. Biological magnification often refers to the process whereby the mercury will increase in concentration as it moves up successive trophic levels: Water (.001 ppm) Algae (.01 ppm) Zooplankton (.1 ppm) Small nekton (1 ppm) Larger fish, etc. (10 ppm) Top predator (100 ppm) This process explains why predatory fish such as swordfish and sharks or birds like osprey and eagles have higher concentrations of mercury in their tissue than could be accounted for by direct exposure to water aloneand ___________ ___________________________________.
Food/Water Contamination Pesticides run off into our water as we spray for bugs and stay on our food. A pesticide poisoning occurs when chemicals intended to control a pest affect non-target organisms such as humans, wildlife, or bees. There are two general types of pesticide poisoning 1. Acute Short-term very high level (suicide or job related) ) General Symptoms fever, intense thirst, increased breathing, vomiting, muscle twitches, pinpoint pupils, inability to breathe, unconsciousness. Results in harm to organs and even death 2. Chronic Long-term low-level exposure (food, alcohol or job) General Symptoms headache, fatigue, weakness, dizziness, perspiration, nausea, diarrhea, loss of appetite, loss of weight, thirstand cancer. According to the National Cancer Institute, pesticides have been shown to cause lymphomas, leukemia, brain, lung, and testicular cancers. The issue of whether certain pesticides cause breast cancer remains unresolved.
Why Children May be Especially Sensitive to Pesticides Infants and children may be especially sensitive to health risks posed by pesticides for several reasons: Their ___________________________________________________________ Achild's excretory system may not be fully developed, the body may not fully remove pesticides. In relation to their body weight, ________________________________more than adults, possibly increasing their exposure to pesticides in food and water. Certain behaviors--such as playing on floors or lawns or putting objects in their mouths--increase a child's exposure to pesticides used in homes and yards. For these reasons we passed __________________________________, EPA carefully evaluates children's exposure to pesticide residues in and on foods they most commonly eat, i.e., apples and apple juice, orange juice, potatoes, tomatoes, soybean oil, sugar, eggs, pork, chicken and beef.
How Pesticides Function LD-50 (__________________): A measurement used to calculate the amount of pesticide it will take, _______________________________________________. ___________________________: The dose below which no toxic or lethal effects are observed and/or above which the toxic or lethal effects are apparent. Simply the minimum dose required to produce toxicity (the moment death rate increases above the norm) ______________________________________ 0.0001 0.001 0.01 0.1 1 10 _____ _______________: The toxicity of two chemicals may be within their safe limits and alone don’t kill organisms. Sometimes two chemicals within their safe limits enter the same ecosystem and will kill organisms. The combination of two or more chemicals within their safe limits that when occurring together become lethal is known as synergism.
How do Pesticides Kill? 1. Pesticides attack the nervous system 2. Herbicides stop photosynthesis: Some herbicides inhibit photosynthesis and prevent chlorophyll formation. 3. Smother the pestwith soaps or vapors 4. Dehydrate them by scratching their exoskeleton with fossilized remains of diatoms. 5. Inhibition of Blood Clotting: Other types of pesticides cause animals (especially rats) to bleed to death by preventing their blood from clotting. The ideal Pesticide • Kills only the target pest. • Does not cause genetic resistance in the target organism. • Disappears or breaks down into harmless chemicals after doing its job. • It stays exactly where it was put and does not move around in the environment. • Be more cost-effective than doing nothing. ________________________
Synthetic Pesticides: Advantages 1. ____________________: Since 1945, DDT and others insecticides have saved 7-500 million people from insect transmitted diseases like malaria (Anopheles mosquito) and bubonic plague (rat fleas). 2. They increase food supplies: about 55% of world’s food supply is destroyed by pests. These would increase without pesticides and food prices would skyrocket. 3. They are _______ and increase profits for farmers. 4. They _________________, are safe to use when used in the approved regulatory manner. 5. Fiber Production: Saves crops like cotton by killing pests like the cotton boll weevil. This keeps clothing cost down.
Synthetic Pesticides: Disadvantages Pesticides accelerate the development of ___________________________________: 1. In response to the application of a pesticide, random genetic variation might allow a few individuals to be resistant to a pesticide. 2. After pesticide application, this small subgroup of the population survives and reproduce, passing the resistance to future generations. Genetic resistance puts farmers on a pesticide (financial) treadmill Because insect generations are relatively short, a pesticide might be rendered ineffective within a few growing seasons due to heightened genetic resistance. In the worst-case scenario, increased resistance, increased cost for more or different pesticides, further increased resistance, further cost ?, continues indefinitely (hence the term treadmill). Farmers are forced to: ________________________________________ ________________________________________. Use a new type of pesticide.
Impact on Non-target Organisms 1. Pesticides ___________________________ 2. Only 2% of the insecticides from aerial or ground spraying __________________________________ 3. Only 5% of herbicides applied to crops reaches the target weeds 4. They ___________________________________ 5. They ___________________________________ 6. The natural predators, and competitors of a pest may be killed by a pesticide and allows the __________________________________________ Examples of resistance: 1. In the U.S., fruit flies that infest orange groves are resistant to malathion. 2. In England, some rats have evolved such a strong resistance to rat poison that they can consume up to five times as much of it as normal rats without dying. 3. DDT is no longer effective in preventing malaria in some places, a fact which contributed to a resurgence of the disease.
Laws and Regulations EPA regulates the use of pesticides under the authority of two federal statutes: the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act (FFDCA). Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA): 1996. Gives the EPA authority to regulate the sale, use and distribution of pesticides. ___________________________________. (Ingredient statement, emergency information, storage and disposal) P.C.H. (800) 222-1222 Federal Food, Drug, and Cosmetic Act (FFDCA): 1996. Gives the EPA authority to set limits on the amount of pesticide residues allowed on food or animal feed. ________________________ ___________________________ Endangered Species Act (ESA): Requires the EPA to assess the risk of pesticides to threatened or endangered species and their habitats. PERSISTENT ORGANIC POLLUTANTS (POPs Treaty): International treaty (Stockholm Convention), (not ratified by US in 2009) to phase out 12 organic persistent pollutants known as the “dirty dozen” such as DDT and PCBs Days to Harvest: The EPA sets the last day you can spray crops before you harvest them for human consumption. This varies from chemical to chemical.
Rachel Carson Rachel Carson published her famous work Silent Spring in 1962 to heightened public awareness and concern _____________________________________________________________ Pesticide sprays, dusts, and aerosols are now applied almost universally to farms, gardens, forests, and homes - non selective chemicals that have the power to kill every insect, the good and the bad, to still the song of birds and the leaping of fish in the streams, to coat the leaves with a deadly film and to linger on soil - all this though the intended target may be only a few weeds or insects. Can anyone believe . . . it is possible to lay down such a barrage of poisons on the surface of the earth without making it unfit for life? They should not be called insecticides, but biocides.”
Integrated Pest Management(IPM) GOAL: ________________________________________________________. A combination of methods to control a pest (not just pesticides). The aim is long term control, not eradication, with minimal environmental impact • Controlling pests: • Acceptable pest levels: allow some to live in an area but take action if the threshold is crossed. • Preventive cultural practices:quarantine, crop sanitation removal of diseased plants. • Fool the pest by _________________________ ________ and selecting pest-resistant varieties. • __________________: Adjusting planting times so that major insect pests either starve or get eaten by their natural predators. • Type of Crops: Switching from _____________ ______________________________________.
6. Mechanical controls: They include simple hand-picking, _____________________________________________up harmful bugs use pheromones to lure pests into traps. • 7. Biological controls: The main focus here is to promote beneficial insects that eat or parasitize target pests. Ex: Biological pest control: Wasp parasitizing a gypsy moth caterpillar. • 8. Using their diseases (bacteria and viruses) to control pests. • 9. Responsible Pesticide Use: Limited use of narrow-spectrum or natural pesticides • 10. ________________: Males of some insect species can be raised in the laboratory, sterilized and released into an infested area to mate unsuccessfully with fertile wild females. The production of organic crops must follow the IPM rules above, according to the United States Department of Agriculture.
Genetic Methods Genetic engineering (GMO) can be used to develop ______________________________ _____________________________________ It is very expensive to develop these, so they are only doing it for large-market crops like wheat, corn, and soybeans. Crossing a modern crop (natural) with its ancestor can bring back some genetic variety lost from modern agriculture. _____________ ____________________________________________________________________________ Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage.
What Can You Do? Reducing Exposure to Pesticides • Grow some of your food using organic methods. • Buy organic food. • Wash and scrub all fresh fruits, vegetables, and wild foods you pick. • _______________________________. • _______________________________.
BIOLOGICAL HAZARDS:DISEASE IN DEVELOPED AND DEVELOPING COUNTRIES Diseases not caused by living organisms cannot spread from one person to another (nontransmissible disease), while those caused by living organisms such as bacteria and viruses can spread from person to person (transmissible or infectious) Transmissible Disease
Infectious (Transmissible) Disease W.H.O. estimates that each year the world’s seven deadliest infections kill 13.6 million people – most of them the poor in developing countries.
Rise of Infectious Disease • __________________of some bacterium (number 1 reason) from the overuse of antibiotics. • __________________________(about 6000 young people, 15-25, are infected with HIV/AIDS each day. • Global economy: Shipping and transporting goods all over the globe • _______________of humans living closely together • ____________________supplies in some countries • ________________________ • Limited access to medicine and vaccines • Increased travel has increased the spread of infectious disease.
Disease The highly infectious tuberculosis (TB-Bacterial) is on the rise and kills 1.7 million people per year. • Lack of TB screening and control programs especially in developing countries due to expenses and they are traveling. • Genetic resistance to the most effective antibiotics. Viral diseases like the Flu, HIV, and hepatitis B infect and kill many more people each year then highly publicized West Nile and SARS viruses. • Pigs, chickens, ducks, and geese are the major reservoirs of flu. As they move from one species to another, they can mutate and exchange genetic material with other viruses. Ecological (or conservation) medicine is devoted to tracking down these connections between wildlife and humans to determine ways to slow and prevent disease spread.
Malaria – Death by Mosquito Malaria kills about 2 million people per year and has probably killed more than all of the wars ever fought. • Malaria is on the rise: • Spraying insides of homes with low concentrations of the pesticide DDT greatly reduces the number of malaria cases. Under the POPs treaty DDT is being phased out in developing countries, ___________________ ______________________. • Decreased ________ populations to the mosquito • increased ___________________ • increasing human population density
Solution Infectious Disease 1. Increase research on tropical disease and vaccines 2. Reduce poverty 3. Decrease malnutrition 4. Improve drinking water quality 5. Reduce unnecessary use of antibiotics 6. Educate people to take all of an antibiotic prescription 7. Reduce antibiotics in livestock 8. Require carful hand washing by all medical personnel 9. Immunize children against major viral disease 10. Conduct global campaign to reduce HIV/AIDS
CHEMICAL HAZARDS Toxic chemicals are __________ to organisms and can cause temporary or permanent harm or even death. Although toxic threats are everywhere, most hazardous wastes come from chemical and petroleum industries (70%) • _________are chemicals or forms of radiation that cause mutations in DNA. Ex: UV, X-rays, Radioactive decay, benzene, arsenic • _______________________are mutations that cause cancer. • _________are chemicals that cause harm or birth defects to a fetus or embryo. Ex: Alcohol • Biological hazards: from more than 1,400 pathogens. • Chemical hazards: in air, water, soil, and food. • Physical hazards: such as fire, earthquake, volcanic eruption… • Cultural hazards: such as smoking, poor diet, unsafe sex, drugs, unsafe working conditions, and poverty. A Black Day in Bhopal, India The world’s worst industrial accident occurred in 1984 at a pesticide plant in Bhopal, India. • An explosion at Union Carbide pesticide plant in an underground storage tank released a large quantity of highly toxic methyl isocyanate (MIC) gas. • 15,000-22,000 people died • Indian officials claim that simple upgrades could have prevented the tragedy.
TOXICOLOGY: ASSESSING CHEMICAL HAZARDS Toxicology is the study of harmful effects of chemicals on the human body. Toxicity is the measure of how harmful a substance is-its ability to cause injury, illness or death to an organism. Factors determining the harm caused by exposure to a chemical include: • 1. The _______________________________ • 2. The _______________________________ • 3. The person who is exposed. • 4. The effectiveness of the body’s detoxification systems. • 5. One’s genetic makeup. Preventable United States For most of human history, pathogenic (disease-causing) organisms were are greatest threat to human health. __________________________ ______________________________________________________________________________.
Risk Analysis Risk is a measure of the likelihood that you will suffer harm from a hazard. Risk analysis involves identifying hazards and evaluating their associated risks. After poverty and gender, the greatest risks of premature death result from lifestyle choice. Most people do not know how to evaluate risk. Many people deny their high risk behavior if they enjoy the activity. Ex: Motorcycling (1 death in 50 participants), Hang gliding (1 in 1250) or driving (1 in 6070 with seat belt) Driving or riding in a car is the most dangerous thing people do. Many people are terrified of: Ex: Killed by gun (1 in 28,000 in U.S.), Lighting (1 in 3 million), airplane crash (1 in 9 million), snakebite (1 in 36 million), West Nile Virus (1 in 1 million) or shark attack (1 in 281 million) Evaluate the risk: 1. Compare risk: What is the risk? Is it worth it? 2. Determine how much risk you are willing to accept. 1 in 100,000 chance of dying is the normal threshold for humans.
Hazard Shortens average life span in the U.S. by Poverty 7–10 years Born male 7.5 years Smoking 6–10 years Overweight (35%) 6 years Unmarried 5 years Overweight (15%) 2 years RISK ANALYSIS Comparisons of risks people face expressed in terms of shorter average life span Spouse smoking 1 year Driving 7 months Air pollution 5 months Alcohol 5 months Drug abuse 4 months Flu 4 months AIDS 3 months Drowning 1 month Pesticides 1 month Fire 1 month Natural radiation 8 days Medical X rays 5 days Oral contraceptives 5 days Toxic waste 4 days Flying 1 day Hurricanes, tornadoes 1 day 10 hours Lifetime near nuclear plant
Why do Males Die Earlier? 1. Males are burdened with natural genetic deficits. Women have two large X chromosomes, men have one X and one smaller Y chromosome. The "spare" X chromosomes allow women's bodies to compensate when faced with damage in ways that men's cells cannot. 2. The womb is more treacherous for boys. Baby boys more likely to die at birth than girls. A weaker immune system, immature lung development, inadequate blood flow to male fetuses, and high vulnerability to maternal stresses seem to be the culprits. 3. Males are more likely to have developmental disorders.Including reading delays, deafness, autism, ADHD, blindness, seizure disorders, hyperactivity, clumsiness, stammering, and Tourette's syndrome are three to four times more common in boys than girls. There are 10 males for every female with Asperger'ssyndrome. 4. They're biologically more prone to risky behavior. Slower development of the area of the brain that governs judgment makes males—especially adolescents—more likely than girls to die in accidents. 5. A "suck-it-up" culture means men often languish with depression. Although women are more likely to make suicide attempts, the ratio of men to women who succeed is nearly 4 to 1. 6. Men choose more dangerous occupations. The bulk of military, firefighters, police officers, construction workers, and farmers are men. 7. Coronary artery disease strikes men early. Estrogen seems to protect women, but it is common for symptoms to begin in men by the age of 35. Making matters worse, men have naturally low levels of protective HDL cholesterol.
Case Study: DDT DDT was first used as a pesticide with great success in the second half of World War II to control malaria (mosquito)and typhus (lice) among civilians and troops. After the war, DDT was made available for use as an agricultural insecticide, and its production and use increased. • Effects on human health • Acts as an ______________________. Endocrine disruptors are chemicals interfere with the endocrine (or hormone producing) system in organisms. • Endocrine disruptors _______________and bind to receptors site on cells fooling the body. • These disruptions can cause cancerous tumors, birth defects, and other developmental disorders. • Sexual development problems such as feminizing of males or masculine effects on females • DDT is still found in humans due to the fact that other countries still use DDT for pest control and the United States imports food from some of these countries. Endocrine disrupting compounds encompass a variety of chemical classes, including drugs, pesticides, compounds used in the plastics (BPA) and even some naturally produced botanical chemicals (soy). Many bioaccumulate and biomagnifyand are categorized as persistent organic pollutants(POP's). These chemicals are used in one region and can be transported long distances and have been found in virtually all regions of the world. DDT has even been found in the eggshells of penguins.
Effects on wildlife Caused __________________and resulted in severe population declines in multiple bird s of prey species.Eggshell thinning caused egg breakage and embryo deaths. Major reason for the decline of the bald eagle,brown pelican,peregrine falcon, and osprey. Even in 2010, more than forty years after the U.S. ban, California Condors which feed on sea lions at Big Sur seemed to be having continued thin-shell problems.