ULO E

• Toxicology


  A scientific discipline that overlaps with biology, chemistry, pharmacology, and medicine involving studying the adverse effects of chemical substances on living organisms and diagnosing and treating exposures to toxins and toxins
• Allergens


  An antigen that produces an abnormally potent immune response where the immune system targets and fights a threat or an invader that could potentially harm the body
• Neurotoxins


  Toxins that are destructive to nerve tissue, an extensive class of exogenous chemical, neurological insults that can adversely affect function in both developing and mature nervous tissue
• Mutagens


  A physical or chemical agent that causes an increase in D.N.A. modifications by altering the organism's D.N.A.
• Teratogens


  Any agent that can disrupt embryonic or fetal development causes a child's congenital disability or may completely cease the pregnancy, including radiation, maternal infections, chemicals, or drugs
• Carcinogens


  Any substance or agents that promote cancer development (carcinogenesis), causing genome damage or disruption of cells' metabolic processes
• Persistent Organic Pollutants (P.O.P.s)


  Organic compounds resistant to biochemical, photolytic, and other environmental degradation processes, sometimes called "forever chemicals", which can bioaccumulate with potentially detrimental effects on ecological and human health
• Acute effects


  A physiological reaction in a human or animal body which cause
• Chronic effects


  Adverse effect on animals or the human body with symptoms that develop slowly, due to prolonged and continuous exposure to low concentrations of a hazardous substance
• Risk assessment


  The combined effort of identifying and analyzing potential events can negatively affect individuals, assets, and even the environment. It also makes mindful judgments on the tolerability of the risk analysis and examines factors influencing it
• Risk Management


  The evaluation, prioritization, and identification of risks followed by coordinated and economical application of resources to control, monitor, and minimize the probability or impact of unfortunate events or to maximize the realization of opportunities
• Pesticides


  Chemical compounds used to eliminate pests, such as insects, rodents, fungi, and weeds. These chemicals are also used in public health to kill disease vectors (e.g., mosquitoes) and pests that damage crops
• Herbicides


  Pesticides used to kill unwanted plants (weeds). There are selective herbicides that explicitly target a weed/s by interfering with its growth without harming the desired crop
• Insecticides


  Any substances that formulate to eliminate or mitigate insects, including ovicides, which are used against insects and larvicides to kill insect larvae
• Fungicides


  Biocidal chemical compounds or biological organisms (plants or animals) used to kill parasitic fungi, or their spores can cause severe damage in agriculture, resulting in decreased yield, crop quality, and profit
• ENVIRONMENTAL HEALTH AND TOXICOLOGY

  The World Health Organization (W.H.O.) defines health as a state of

  complete physical,mental, and social well-being. A person can be ill to some extent;

  however, health can beimproved to live a happier, longer, and more productive and

  satisfying lives. The disease can also be influenced by environmental factors such
• Global Burden of Disease (GBD)


  A comprehensive regional and global research program of disease burden that assesses mortality and disability from major diseases, injuries, and risk factors
• Global Burden of Disease (GBD)


  • Considers the health, social, political, environmental, and economic factors to determine the cost that particular disease and disability exert upon the individual and society
  • Mortality data is now based on Disability Adjusted Life Years (DALYs) as a measure of disease burden
• Smallpox was completely wiped out

  1977
• Has been eliminated everywhere in the world except for a few remote villages in northern Nigeria

  Polio
• Epidemics of typhoid fever, cholera, and yellow fever are now rarely encountered
• AIDS has become a highly treatable disease
• Chronic diseases now account for nearly 60% of the 56.5 million total deaths worldwide each year and about half of the global disease burden
• EMERGENT DISEASE

  Emergent diseases are those not previously known or that have been absent for

  at least 20 years. Rapid international travel makes it possible for these new diseases to

  spread around the world at jet speed. Epidemiologists warn that the next deadly

  epidemic is only a plane ride away
• Emergent diseases in humans and ecological diseases in natural communities

  arise due to stresses in biological systems that upsets normal ecological relationships.

  These growing concerns are adverse synergistic interactions between emerging

  diseases and other infectious and non-infectious conditions leading to the development

  of novel syndemic. Many emergent diseases originated from a non-human animal

  species, such as HIV which originated in chimpanzees, and SARS which came from the

  Masked Palm Civet native to China
• Factors Contributing to Disease Emergence:

  1. Microbial adaption - e.g., genetic drift and genetic shift in Influenza A

  2. Changing human susceptibility - e.g., mass immunocompromising with

  HIV/AIDS

  3. Climate and weather - e.g., diseases with zoonotic vectors such as West

  Nile Disease (transmitted by mosquitoes) are moving further from the

  tropics as the climate warms.
• 4. Change in human demographics and trade - e.g., rapid travel enabled

  COVID to rapidly propagate around the globe

  5. Economic development - e.g., use of antibiotics to increase meat yield of

  farmed cows leads to antibiotic resistance

  6. Breakdown of public health - e.g., the current situation in Zimbabwe

  7. Poverty and social inequality - e.g., tuberculosis is primarily a problem in

  low- income areas

  8. War and famine – e.g., Gulf war, Ukraine war

  9. Bioterrorism - e.g., 2001 Anthrax attacks

  10.Dam and irrigation system construction - e.g., malaria and other mosquito

  borne diseases
• Ecological epidemiology


  The study of the ecology of infectious diseases
• Ecological epidemiology


  • Includes population and community level studies of the interactions between hosts and their pathogens and parasites
  • Covers diseases of both humans and wildlife
• Ebola hemorrhagic fever


  • Kills up to 90% of its human victims
  • A global outbreak killed ¼ of all the gorillas
• Chronic wasting disease (CWD)

  • Caused by a prion
  • One of a family of irreversible, degenerative neurological diseases known as transmissible spongiform encephalopathies (TSE) that include mad cow disease in cattle, scrapie in sheep, and Creutzfelt-Jacob disease in humans
• Tropical diseases have been moving into areas from which they were formerly absent as mosquitoes, rodents, and other vectors expand into new habitat
• Resistance to Drugs, Antibiotics, and Pesticides

  The protozoan parasite that causes malaria is now resistant to most drugs, while

  the mosquitoes that transmit it have developed resistance to many insecticides. The

  following are the reasons for antibiotic resistance to develop - Antibiotics do not work

  against certain diseases, e.g., viral infections. They are given when the person could

  recover fully without them and starting and not finishing a full prescription. Hence, there

  is also a widespread use of antibiotics in animal agriculture.
• Ecotoxicology is the study of toxins (poisons) and their effects, particularly on

  living systems because many substances are known to be poisonous to life (whether

  plant, animal, or microbial). It is a broad field, drawing from biochemistry, histology,

  pathology, pharmacology, and many other disciplines. Toxin’s damage or kill living

  organisms because they react with cellular

  components to disrupt metabolic functions. They are harmful even in extremely dilute

  concentrations. In some cases, billionths, or even trillionths of a gram can cause

  irreversible damage
• Allergens


  Immune-activating agents
• Allergens


  • Some act as antigens directly - white blood cells recognize them as foreign and stimulate production of specific antibodies
  • Some function indirectly by linking and modifying the composition of foreign materials, becoming antigenic and inducing an immune system response
• Allergens


  • Formaldehyde
• Formaldehyde


  A widely used chemical that is a potent sensitizer of the immune system
• Formaldehyde


  • It is directly allergenic
  • It can also trigger reactions to other substances
• Formaldehyde concentrations in indoor air can be thousands of times higher than in healthy outdoor air