Environmental Health And Toxicology Notes PDF

Keystone Species ENVIRONMENTAL HEALTH AND - Presence has influence in the TOXICOLOGY environment 1. Predator LANGUAGE 2. Ecosystem engineer 3. Mutualist...

Keystone Species ENVIRONMENTAL HEALTH AND - Presence has influence in the TOXICOLOGY environment 1. Predator LANGUAGE 2. Ecosystem engineer 3. Mutualist Toxicology 4. Prey species Allergens 5. Seed Disperser Neurotoxins - Refers to toxins that are Community Dynamics destructive to neve tissue - Structure of an environment - Which affects the function in tissue - Changes over time - Can be changed because of natural Mutagens and anthropogenic activities - Damages our DNA (creates - Species are at an equilibrium state mutations) - A broader term that there are Teratogens changes happening in an - Disrupt embryonic or fetal environment development Carcinogens Ecological Succession - Promote cancer development - - Appearance and disappareance of a through carcinogenesis species after a severe disturbance Persistent Organic Pollutants (POPs) - Involves series of changes - Forever chemicals - Change in an ecosystem - Resistant to environmental - It takes years to happen/occur degradation processes - Has stages: - Organic compounds 1. Primary Succession - Occurs Acute Effects in lifeless and pioneer - Severe effects species are the ones who Chronic effects colonize everything - Symptoms that develop slowly 2. Secondary Succesion - even Risk assessment after a disturbance but the - Identifying and analyzing chances soil is still intact, there is still of being harmed a chance for recovery Herbicides (grasses and shrub growth) - Uses to kill unwanted plants 3. Climax Community - final (weeds) stable stage of succession Insecticides where everything becomes - Elliminate insects in plants balanced again Fungicides - Used to kill parasitic fungi Environmental Health  - Multidisciplinary field that focuses on Chemical - exposed to natural or synthetic the understanding and managing chemicals (pesticides, pharmaceuticals, and the interactions between the heavy metals) environment and the health of a person Global Burden of Disease (GBD) - Focuses on disease-causing - GBD is a comprehensive regional external factors (like the earth’s and global research program of climate system) thus affects the disease burden physical and the psychological - Assesses mortality and disability aspect of a person from major disease, injuries, and risk factors Health - GBD assesses health, social, - Acc. To WHO, it is a state of political environmental, and complete physical, mental, and economic elements in the impact of social well-being diseases - Disability-adjusted life years Disease (DALY’s) is a tool that measures the - Impairment of an individual’s effects of a disease on the well-being population - Factors are environment and - Eradicated diseases: smallpox lifestyle (diet, heredity, stress, etc.) (1977) and polio (eliminated globally - Factors morbidity (illness) and but still present in some area) mortality (death) - Infectious and emergent diseases Pathogens continue to kill millions of people - Infectious agents globally - Bacteria, viruses, fungus - Pathogens affecting humans Trauma include virus, bacteria, protozoans, - Accidents parasitic worms, and flukes Pollution - Air, water, noise, etc. Parasites Radiation - Pinworm - UV nuclear waste - Whipworm Toxins - Hookworm - Smoking, metals like mercury and lead, chemical exposure from Protozoa pesticides, herbicides, cleaning - Malaria - Amoebiasis or amoebic dysentery solution - African sleeping sickness or Trypanosomiasis CATEGORIES OF HUMAN HEALTH RISK - Trichomoniasis Physical - cause injurty or loss of life (natural disaster) Fungi Biological - involving diseases (most - Ringworm - Nail infectious deaths) - Vaginal yeast infection  - Genetic drift and genetic shift - Pneumonia - Athlete's foot in Influenza A. 2. Changing human susceptibility Prokaryote - Mass immunocompromising - Bubonic plague with HIV/AIDS - Food infection (salmonella) 3. Climate and weather - Ulcer - Diseases with zoonotic Virus vectors such as West Nile - Colds Disease (transmitted by - The flu mosquitoes) are moving - COVID-19 further from the topics as the - Norovirus (stomach flu) climate warms - HPV (warts) 4. Change of demographics and trade - Dengue fever and yellow fever - rapid travel enabled COVID Prion to rapidly propagate around 1. Alper’s syndrome - affects the the globe young and causing dementia, 5. Economic development seizure, liver damage - Use of antibiotics to increase 2. Gerstman-staüssler-scheinker meat yield of farmer cows syndrom (GSSS) - progressive leads to antibiotic emergence ataxia (poor muscle control) 6. Breakdown of public health 3. Fatal Familial Insomnia (FFI) - leads to severe insomnia - The current situation in Zimbabwe Key child killers 7. Poverty and social inequality - Diarrhea - Tuberculosis is primarily a - Acute respiratory illnesses problem in low income area - Malaria 8. War and famine - Measles - Tetanus - Gulf war and ukraine war 9. Bioterrorism - Anthrax attacks Infectious diseases 10. Dam and irrigation construction - Caused by pathogenic - Malaria and mosquito borne microorganisms such as bacteria diseases and viruses - Influenza, tuberculosis, HIV/AIDS, Ecological epidemiology Malaria, COVID 19 - Ecology of infectious diseases Emergent diseases - It includes population and - Those not previously known or that community level studies of the have been absent for at least 20 interactions between the years pathogens, hosts, and the environment Factors contributing to disease emergence (examples only) Toxicology 1. Microbial adaptation  - Study of toxins and poisons and attaching to target organs; their effects on living organisms can cause breast cancer - Study of adverse effects of external 4. Neurotoxins factors - Targets nerve cells - Inhbits enzyme that regulate Chemicals are divided toxic (poisonous) - signal transmission known poisons that can kill cells and tissues 5. Mutagens - Damage or modify the and hazardous (dangerous) - flammable, genetic material (dna) in cells explosive, irritant such as radiation and chemicals Toxicants - are toxic substances from - Damage DNA leading to birth chemicals defects - physical mutagens: xray, Toxins - are poisonous substances gamma ray produced within living cells - Chemical: chromium, nickel - Biological: biological Toxin’s damage or kill living organisms mutagens bacteria because they react with cellular 6. Teratogens components to disrupt metabolic functions - Chemical substances or other factors which cause Ecotoxicology studied poisons and the different abnormalities during effects BUT mainly focuses on plants, embryonic growth and animals, and microbials development - Alchol is probably the most Effects of toxins popular teratogen in the 1. Allergens - immune-activating world; cause fetal alcohol agents; causes allergic reactions syndrome (Antigens - allergens that make 7. Carcinogens ubsick…) - Substances that cause 2. Immune system depresant - cancer weaken the immune system weak - Benign: non cancerous 3. Endocrine system disruptors - are - Malignant: cancerous chemicals that disrupts the natural activity of hormones ENVIRONMENTAL HEALTH AND - Interfere with the functions of TOXICOLOGY normal chemical - Hormone mimics: similar Bioaccumulation and Biomagnification shape to natural hormones increase concentration of toxins and amplify their effects; cause chromosomal Bioaccumulation - build up of a toxic numbers chemical in the tissue of an organism - Hormone blocker: prevents - Increase in the concentration of a natural hormones from substance inside an organism  - Takes places within a given trophic - some substances have antagonistic level reactions in which materials will interfere with the effects or will Biomagnification - increased concentration somehow stimulate the breakdown of a toxic chemical, the higher an animal is of others chemicals (like vitamins on the food chain fighting pollutants): has Additive - An increase in the level as one effect moves higher in the food chain - Synergisms means when multiple - Biomagnification takes place pollutants are combined and their between two given trophic levels effects add and doubles - Additive effect (double the effect); Persistent organic pollutants Synergism (intensify the effect) - Organic compounds are resistant to biochemical, photolytic, and other Factors influencing toxicity environmental degradation processes - Sources: Toxic and Hazardous - Also known as “forever chemical” chemicals; they target both biotic 1. Polybrominated diphenyl ethers and abiotic community (PBDE) - Dose (amount), route of entry, timing - Known as flame retardants of exposure, sensitivity of the usually used in textiles and organism plastic compounds - Attacks our nervous system A. Factors related to toxic agent 2. Perflourooctane sulfonate (PFOS) 1. Chemical composition and the and Perflourooctanoic acid reactivity (PFOA) 2. Physical characteristics (solubility, - Also known C8 are widely state) used as nonstick, waterproof 3. Presence of impurities or stain-resistant production contaminants such as Teflon 4. Stability and storage characteristics 3. Phthalates (thalates) of a toxic agent - Disrupts hormones 5. Availability of vehicle (such as the - Found in plastics solvent) to carry agent 4. Perchlorate 6. Movement of the agent through the - Waterborne contaminant environment and into cells - Utilized by rockets 5. Bisphenol A (BPA) B. Factors related to exposure - Synthetic compound used in 1. Dose plastics resins 2. Route, rate, and site of exposure - May alter sexual 3. Duration and frequency of exposure development in both males 4. Time of exposure and females C. Factors related to organism Chemical Interactions increasing toxicity  1. Storage, cell permeability of agent - Hazard (potential to harm you) vs and resistance to ingestion Risk (the likelihood of a hazard 2. Ability to metabolize, inactivate, causing harm) sequester, or eliminate the agent - Exposure assessment refers to 3. The tendency to activate or alter measuring and characterizing: nontoxic substances, so they magnitude, frequency, duration, and become toxic route of exposure 4. Concurrent infections or physical or chemical stress 1. Hazard identification 5. Species and genetic characteristics - Assess if one can cause of an organism harm 6. Nutritional status of the subject 2. Dose-response assessment 7. Sex, body, weight, age, maturity, and - Determine the relationship of immunological status the dose of a chemical and its health effects on people Measuring toxicity - Usually tested on anims (e.g - To determine a dose to which 50% rats) of the test population is sensitive or - EXPOSURE APPRAISAL - the lethal dose (LD50) assesses the duration, - Most used way is to test it on frequency, and intensity of animals human exposure to a (chemical) pollutant LD50 3. Exposure assessment - A term used in toxicology as a - Challenging and often measurement of a lethal dose of a controversial because of substance (pathogen, meds, toxic difficulties in accurately substances, etc.) measuring very small toxin - LD50 represents the dose at which a concentrations substance is lethal for 50% of tested - Needs to be precise - Requires a lot of preparation Acute effects 4. Risk characterization - Caused by a single exposure to the - Outlines the health risks from toxin exposure to a pollutant or toxin by evaluating the Chronic effects magnitude of potential - Effects are permanent hazard Risk assessment TOLERANCE - Risk is the possibility or results of - Ability to resist or withstand stress suffering harm or loss from exposure to pollutant - RA is the scientific process of TYPES OF TOLERANCE estimating the threat that 1. Behavioral - Organisms learn to avoid toxicants  2. Physiological Organo ambot - Bodies learn to fight back Fumigants (metabolize) toxicants Inorganic pesticides - broad spectrum - The organisms’ bodies adapt poison to fight Natural organic pesticides (botanicals) - - Alcohol - some develop higher enzymes to metabolize alcohol 3. Genetic - Genetic mutations that develop resistance AGRICULTURE - Science and art of growing plants and other crops - Also cultivating animals for food - Also includes the economy/economic factor Impacts of agriculture to the environment 1. Land transformation - Deforestation - Landscape degradation (refers to the long-term decline in ecosystem function and productivity; causes SOIL EXHAUSTION, SOIL SALINIZATION, OVERGRAZING, FREQUENT BURNING, AND LOSS OF SOIL BIODIVERSITY Pesticides Insecticides - insects herbicides - plants (Weed) rodenticides - rodents bactericides (bacteria) fungicides - fungi larvicides - larvae Organophosphate