Transcript Toxicology
Toxicology The study of poisons and their effects, on living systems Love Canal Cleanup Finished, Mutants Return to Homes We knew there were too many miscarriages, too many birth defects, too many central nervous system problems, too many urinary tract disorders, and too much asthma and other respiratory problems among us." Health: A state of complete physical, mental, and social well-being Disease: A deleterious change in the body’s condition in response to an environmental factor that could be nutritional, chemical, biological, or psychological Morbidity: Illness Types of Environmental Health Hazards Infectious Diseases Toxic Chemicals Natural or Synthetic Toxins Physical Agents, Trauma and Stress Diet Pathogens are infectious organisms Bacterial Protozoans (guardia) Fungal Invertebrate Animals Viruses are non living Bacterial Infections: Trachoma is an inflammation of eye Sexual Transmitted Diseases (gonorrhea and syphilis) Respiratory Diseases: Pneumonia, tuberculosis, influenza, and pertussis Bacteria have developed resistance to antibiotics Improved drugs and sanitation can eliminate some diseases Trachoma,the most commonly contracted STD, caused by Chlamydia trachomatis Emergent diseases Those not previously known or that have been absent for more than 20 year *many are viruses Viral Infection SARS and Bird flu HANTA, Ebola West Nile virus causes encephalitis HIV and AIDS Fungal Sudden oak death Fungal spores *black mold Protozoans Malaria: Infection of red blood cells by the protozoan Plasmodium spread by the Anopheles mosquito Giardia: dysentery Amoeba:dysentery Invertebrate Animals (Parasitic) Flatworms (flukes) and tapeworms Nematodes (roundworms) – – – such as hookworms, guinea worms Filariasis worms block lymphatic vessels causes elephantiasis Caused by Nematodes (Roundworms) Elephantiasis Filariasis Guinea worms prions Proteins resistant to temperature. They cause Chronic Wasting in Wild Animals and Mad Cow Disease also known as Creutzfelt-Jacop disease Toxic Chemicals Hazardous: Dangerous Toxic: Poisonous Irritants: Corrosives (acid), caustics (base), and other substances that damage biological tissues Respiratory Fibrotic Agents: Irritants that damage the lungs Asphyxiants: Chemicals that exclude oxygen or actively interfere with oxygen uptake and distribution (i.e. MIC) Allergens: Substances that activate the immune system. Some act as Antigens which are recognized as foreign by white blood cells. Antigens cause the immune system to produce Antibodies. Mutagen: with change the base sequence in DNA, may be harmless or harmful. Cancer: Invasive, out-of-control cell growth that results in malignant tumors Carcinogens: Substances that cause cancer Promoter: Bases sequences in DNA that regulate expression of that gene Terratogens: discussed further Mutagens: Agents that damage or alter DNA Teratogens: Factors that cause abnormalities during embryonic growth and development (example: thalidomide) – – Fetal Alcohol Syndrome: Symptoms including craniofacial abnormalities, developmental delays, behavioral problems, and mental defects. Thalidamine: used to prevent morning sickness and in treatment of leprosy. Thalidomide for morning sickness Carcinogens aflatoxin acrylamide Francis Oldem Kelsey Prevent FDA from approving Prevented 1000 birth defects in USA Awarded President’s Award for Distinguished Federal Civilian Service Endocrine Disrupters Neurotoxins: Attack nerve cells – – – Heavy metals (mercury, lead) Chloronated hydrocarbons (DDT, dioxin) disrupt nerve cell membranes Organophosphates (pesticides organophosphates mercury How Do Environmental Toxins Enter Our Bodies? introduced into our lives everyday depend on where we live They are in the air you breath, the food you eat, water, buildings, pesticides, and consumer products. They are the byproducts of industry Basic Concepts Def: science that studies poisons or toxics Pathways from environment -> us – – – oral ingestion inhalation percutaneous absorption (skin) 17.8% of California’s lakes are under fish consumption advisories due to mercury, dioxins and other Persistent Bioaccumulative Toxins!!! The average household uses and stores more than 60 hazardous materials, including household cleaners, automotive products, paints, solvents and pesticides Household sources of Toxic Chemicals Off the shelf pesticides, herbicides, fungicides and insecticides Paints and paint cleaning supplies Household cleaning solutions, laundry detergents with phosphates Bleached paper products Over 150 chemicals found in the average home have been linked to allergies, birth defects, cancer and psychological abnormalities Consumer Product Safety Commission www.earthwellness.com Some of the biggies Dioxin is an unintentional bi-product of industrial processes using chlorine. It includes more than 200 chemicals. PVC, Polyvinyl Chloride, is the most widely used plastic Physical Agents, Trauma, and Stress Trauma: Injury caused by accidents or violence Stress: Physical, chemical, or emotional factors that place a strain on an organism for which there is inadequate adaptation Movement, Distribution and Fate of the Toxin Solubility water vs fat soluble Bioaccumulation and Biomagnification Persistence Chemical Interaction Bioaccumulation and Biomagnification Bioaccumulation: The ability of cells to absorb and store of a select molecules When is this beneficial vs detrimental? Biomagnification: the toxin level accumulates in those organisms higher up in the food chain. i.e. DDT Chemical Interactions Antagonistic: One chemical counteracts the effects of another – Vitamins A, C, and E reduce response of some carcinogens Additive and Synergistic: : two chemical that occur together exacerbates the effects of another How Do We Measure Toxicity Animal testing Toxicity ratings Acute verses chronic doses and effects Detection limits Animal Testing LD50: The dose of a toxic chemical to which 50% of the test population is sensitive 9.11, 9.12 Acute vs Chronic Doses and Effects Acute Effects: Effects causes by a single exposure to the toxin resulting in an immediate health crisis Chronic Effects: Long lasting or permanent effects Exposures: If long lasting can be chronic 9.13 Fig 8.17 Risk Risk: The probability of harm times the probability of exposure Assessment & Management High Risk: Habitat destruction, loss of biodiversity Medium Risk: Toxins Low Risk Oil Spills, Radionuclides What happened in Bhopal, India? Methylisocyanate An irritant, causes burning and swelling of soft tissue The lack of oxygen lead to death Blindness to the survivors What happened in Chernobyle How Can We Reduce Our Risk of Exposure to Environmental Toxins? Increase your awareness pass that knowledge on to friends and family Limit your exposure to toxic chemicals by knowing what is in the products you buy for yourself and family. Use minimal amounts of organic pesticides and fertilizers and encourage your neighbors to do the same Express your views to and make demands on your local representatives, school board, federal agencies Change your lifestyle by minimizing your use and exposure to toxic substances! Encourage those around you to change theirs Buy organic fruits and vegetables, meats, and dairy products as much as possible. Limit your use of products (toilet paper, tampons, and other paper products) which have been through a chlorine process to whiten the product. Limit your exposure to plastic products. Use minimal amounts of organic pesticides and fertilizers and encourage your neighbors to do the same.