TEST WEDNESDAY

Toxicology PoisonStudy of Study of toxic (harmful) substances on organisms, including their nature, effects, detection, methods of treatment, and exposure control. *determines how poisonous a substance is.

Toxicity : How Dangerous Is It? We need to know how much of the pollutant is in the environment and how much gets into the body.

Dose: the amount of a harmful chemical to which a person is exposed to The toxic effect of a certain dose of a chemical on a person’s health depends on: 1. The person’s size 2. The number of times a person is exposed 3. How well the person’s body breaks down the chemical Bigger person, bigger dose More exposure = more in your body Some people have better metabolism (ability to break down) than others

Damage to health that results from exposure to a given dose is called: RESPONSE The toxicity of a chemical can be expressed as: Dose-response curve Shows the relative effect of various doses of a drug or chemical on an organism(s) as determined by experiments

Persistent Chemical: chemical that breaks down slowly in the environment Example: Pesticide DDT Very dangerous because we are more likely to get in contact with the chemical and remain in the body

Epidemiology Spread of disease Study of Study of the spread of disease. (Big surprise, right?)

Scientists use epidemiology to find: 1. The origin of the disease 2. How the disease spreads 3. How to prevent the disease from spreading Like what we did in our disease transmission activity! Patient 0: Zaid Hassan

In Epidemiology, scientists and health officials work together on risk assessments for pollutants Risk Assessment: estimate of the harm or negative effect that might be caused by a substance (pathogen) Leads and informs government agencies, like the Environmental Protection Agency (EPA), to formulate regulations to ban or allow pollution causing substances when they pose a risk to human health.

Pollution from Natural Sources Particulates Natural Metals Particles in the air that are small enough to breathe into the lungs Metals like arsenic, cadmium, lead, and mercury *Can cause asthma, bronchitis, and lung cancer *Can cause nerve damage when they are ingested (eaten) in large doses Can become hazardous when they are above normal levels

Coal  Black Lung Disease Mining can often cause various health problems for the workers. Nasty.

Pollution from Human Activities Burning Fuels Pesticides In vehicles, homes, furnaces, powerplants, and factories Chemicals designed to kill unwanted organisms such as insects, fungi, or weeds. Typically used in agriculture and landscaping. Releases carbon monoxide and particulates *Can cause nerve damage, birth defects, and cancer

Pollution from Human Activities Industrial Chemicals Waste Disposal Toxic chemicals used to make building materials, carpets, cleaning fluids, and furniture. Much of the pollution in the environment is a result of inadequate waste disposal Lead poisoning, PCB poisoning, etc.

Break Time (5 min)

Biological Hazard Diseases from live organisms. Like bacteria.

Infectious diseases are caused by pathogens Organisms or viruses that causes disease. Some are spread by AIR  Tuberculosis and Whooping Cough Some are spread by drinking water Pollution can cause illness indirectly because many pathogens breed in or are spread by polluted water *Most infectious diseases are transmitted this way. Causes health problems because they become trapped in the tiny air sacs in the lungs and cause irritation

Some diseases are spread by a HOST Organism in which a pathogen lives all or part of its life

Some diseases are spread by a HOST  Malaria is transmitted by being bitten by a mosquito vector Organism in which a pathogen lives all or part of its life Vector: An organism that transmits a disease (pathogen or parasite) to another organism

Some diseases are spread by INGESTION (eating) Caused by poor sanitation and can lead to gastrointestinal infections (Stomach) from bacteria in food

Antibiotic Resistance Our actions cause pathogens to evolve resistance to antibiotics that are used to kill them. Makes it difficult to control. Bacteria and germs get stronger and stronger with more antibiotics (medicines and chemicals) Some examples of bacteria that developed resistance: E. Coli Tuberculosis Bacteria Pneumonia Bacteria Salmonella

Aww…

Emerging Viruses Viruses and diseases that were unknown 100 years ago. HIV Hanta virus Ebola Virus