330 likes | 432 Views
Foundations of Public Health PH-200 Fall 2008. Nutrition and Food Safety. Escherichia coli 0157-H. Week 7. http://www.scientiafoodsafety.com/super_safemark_classes. Outline. 9:30 AM – 9:45 AM : Questions and Review 9:45 AM – 11:00 AM : Milestones: Nutrition 11:00 AM – 11:15 AM : Recess
E N D
Foundations of Public HealthPH-200 Fall 2008 Nutrition and Food Safety Escherichia coli 0157-H Week 7 http://www.scientiafoodsafety.com/super_safemark_classes
Outline • 9:30 AM – 9:45 AM : Questions and Review • 9:45 AM – 11:00 AM : Milestones: Nutrition • 11:00 AM – 11:15 AM : Recess • 11:15 AM – 12:15 PM : Theoretical Foundations – Natural Sciences • 12:15 PM – 12:30 PM : Review
Pop-quiz • What is the leading cause of mortality/morbidity in Orange County? • How is the burden of disease associated with this cause distributed geographically/demographically in the County? • What are the major explanatory factors for the distribution? • What are the preventive strategies in place or that could be implemented to relieve the burden of these diseases in Orange County?
Guidelines for Proposal Writing The purpose of the proposal writing assignment is to build on the scholarly review assignment that focuses on understanding the state of knowledge about a particular disease burden within a socio-demographic scope. The scholarly reviews should reveal questions for further studies to address gaps in public health knowledge or practice. The proposal should present a comprehensive strategy to advance knowledge in public health, or to translate current knowledge into practices that will improve the health of communities. The National Institutes of Health (NIH) is the federal agency that supports fundamental and applied research in public health. In addition, NIH supports graduate fellowships and implementation projects. Other federal agencies including the Environmental Protection Agency also support graduate fellowships on topics related to public health (e.g. see http://epa.gov/ncer/rfa/2009/2009_star_gradfellow.html). In addition, private foundations such as the Bill and Melinda Gates Foundation, and the Robert Wood Johnson Foundation also support public health research and practice.
Proposal Guidelines - continued The priority for this assignment is that each student learns the process of turning ideas in public health into substantial proposals that can win awards and help transform those ideas public health support infrastructures and processes. Each student is free to identify a potential funding agency and structure their proposal writing to accommodate the guidelines of that particular agency. Therefore, please review the list of NIH agencies and read about the agency that most closely works on a topic of interest to you. In order to ensure fairness in workload, proposals should be 7,000 +/- 500 words. Feel free to use graphics and images. All proposals should have the following sections: • Summary • Problem Statement • Hypothesis • Methods (including compliance with Human Subjects ethical treatment guidelines, where applicable) • Budget • Significance of Expected Results
Nutrition and Public Health • “Medical Geology” • http://www.medicalgeology.org/welcome_to_the_home_page_of_the_.htm • Balanced Diet (Building a Food Pyramid on “shifting sands’) • Pathogens (From E. coli 0157H to Mad Cow Disease) • Pesticides and Fertilizers • http://www.psrla.org/documents/pesticides_and_human_health.pdf • Food import/export and Homeland Security • USDA (http://www.fsis.usda.gov/Food_Defense_&_Emergency_Response/index.asp) • Food and Drug Administration • http://www.fda.gov/
Between deficiency and poisoning • Natural trace chemicals, crop nutrient values and water supply Essential Non-Essential
Medical Geology • Selenium distribution in the U.S. Selenium is a good antioxidant. Blueberries are good sources of selenium
Selenium-Accumulating Plants • Selenium is accumulated by a number of plants in sufficient amounts to be toxic if consumed by livestock. Plants that accumulate high amounts of selenium and may require selenium for growth are often found in selenium rich areas. Historically these plants have been called indicator plants. • The indicator plants include certain species of Astragalus, prince's plume, and some woody asters. The indicator plants may accumulate up to 3000 parts per million (ppm) selenium.
Selenium Toxicosis • Selenium is required in the diet of most animals. Concentrations of 0.3 ppm are recommended for most food producing livestock. Acute selenosis has been associated with ingesting large amounts of selenium such as would happen if animals eat indicator plants (>400 ppm). • Oral selenium doses of between 1 and 5 mg/kg body weight are considered toxic. Lower doses of between 5 and 40 ppm in the diet for several weeks or months result in chronic poisoning, oftentimes called alkali disease. • The mechanism of toxicity is not completely understood, but the clinical and morphologic lesions suggest glutathione depletion and secondary lipid peroxidation are important in pathogenesis.
Signs and Lesions of Poisoning • Acute Poisoning: • Lethargy, nonresponsiveness • Dyspnea with abnormal posture • Unsteady gait • Diarrhea • Abdominal pain (teeth grinding) • Increased pulse, respiration rate and body temperature. • Prostration • Death (Sheep may not show signs and are found dead) • Necropsy and histologic lesions include pulmonary edema, hydrothorax, and pale myocardium. Additionally there may be mild enteritis and passive congestion of the liver • Chronic Poisoning: • Dullness • Rough hair coat • Emaciation • Lack of vitality, anemia • Lameness, joint stiffness • Hooves may become overgrown or deformed (circular bumps or breaks below coronary band) • Loss of long hair (horses commonly lose their mane and tail) • Histologic lesions variable but often include cardiomyopathy and liver cirrhosis • Reproductive losses in cattle
Bird flu and Selenium? • Selenium and immunity
Pellagra and Vitamin B (niacin) deficiency • Pellagra, a loathsome skin disease, it was called mal de la rosa and often mistaken for leprosy. In the United States, pellagra has often been called the disease of the four D's -- dermatitis, diarrhea, dementia, and death.
Population-level “prevention” • Nutrient additives/supplements • ITALIAN BREADEnriched flour (wheat flour, barley malt, niacin, iron, thiamin mononitrate, riboflavin, folic acid), water, sugar, contains less than 2% of the following: soybean oil, yeast, salt, wheat protein isolate, wheat gluten, dough conditioners (acetylated tartaric acid esters of mono- and diglycerides, ammonium sulfate, calcium sulfate, ascorbic acid, azodicarbonamide, potassium iodate, amylase [enzymes]), sodium stearoyl-2-lactylate, mineral oil.
“Cheap” public health interventions • Folic acid deficiency = megaloblastic anemia. • Riboflavin deficiency = Hypersensitivity to light; the skin becomes greasy, scaly, and dry. There may be cracks, or fissures, at the corners of the mouth, inflammation and soreness of the lips, and a smooth, reddish-purple tongue.
Pathogens in Food • How did you vote on California Proposition-2 (2008)? • 76 million annual cases of food poisoning in the U.S. • 1/100 hospitalizations • 1/500 deaths • Salmonella • E. coli O157-H7 • Cyclospora
Pesticides and Food Production • http://www.psrla.org/documents/pesticides_and_human_health.pdf Child of farm workers, born with birth defects attributable to pesticides. Source: Sarasota/Manatee Farmworker Supporters
Genetically engineered foods • International controversy, but not in the U.S.
Golden Rice and the Burden of Blindness • Golden rice is a variety of rice (Oryza sativa) produced through genetic engineering to biosynthesize beta-carotene, a precursor of pro-vitamin A in the edible parts of rice. • Vitamin-A Deficiency- VAD is responsible for 1–2 million deaths, 500,000 cases of irreversible blindness and millions of cases of xerophthalmia annually.
Food “security” • Melamine (“fake” protein)
Regulations • FDA • USDA • DHS • EPA • FAO
Public Health Theory • “You cannot get an ought from an is” • David Hume (1711-1776): Empiricist • (Descriptive versus Prescriptive) • critical realism is the theory that some of our sense-data can and do accurately represent external objects, properties, and events, while other of our sense-data (for example, those of secondary qualities and perceptual illusions) do not accurately represent any external objects, properties, and events. In short, critical realism refers to any position that maintains that there exists an objectively knowable, mind-independent reality, whilst acknowledging the roles of perception and cognition.
Induction • The cornerstone of Hume’s epistemology is the so-called Problem of Induction: it has been argued that it is in this area of Hume’s thought that his skepticism about human powers of reason is the most pronounced. • The problem concerns the explanation of how we are able to make inductive inferences. • Inductive inference is reasoning from the observed behavior of objects to their behavior when unobserved; as Hume says, it is a question of how things behave when they go “beyond the present testimony of the senses, and the records of our memory”.Hume notices that we tend to believe that things behave in a regular manner; i.e. that patterns in the behavior of objects will persist into the future, and the unobserved present.
Causation • The notion of causation is closely linked, in Hume, to the problem of induction. Hume saw induction as reasoning on the basis of patterns in the observed behavior of objects, and these patterns were essentially causal. • However, Hume’s views on the concept of causation are much disputed. There are (at least) three interpretations in the literature: • (1) the logical positivist interpretation; • (2) the skeptical realist interpretation; and • (3) the quasi-realist interpretation. • The major disagreement with the positivists focuses on the notion of necessary connection. According to the positivists, as we have seen, causation consists solely in regular succession; but skeptical realists point out that Hume also thought our concept of causation was of that of a necessary relation.
More public health theory please – but make it adequate • Jim Connelly’s article in Journal of Public Health • References 3, 4, 6, 8, 9, 12