Title: Toxicology and Human Health
1Toxicology and Human Health
2Toxicology and Human Health
- Risk and Hazards
- Risk - the possibility of suffering harm from a
hazard that can cause injury, disease, economic
loss, or environmental damage
3Toxicology and Human Health
- Risk and Hazards
- Probability - a mathematical statement about how
likely it is that some event will occur - Ranges from 0 ( absolute certainty of no risk) to
1 (absolute certainty of risk)
4Toxicology and Human Health
- Types of Hazards
- Cultural Hazards
- Poor diet
- Unsafe sex
- Chemical Hazards
- Harmful chemicals in air, water, soil, food
5Toxicology and Human Health
- Types of Hazards
- Physical Hazards
- Ionizing radiation
- Noise
- Natural disasters
- Biological Hazards
- Pathogens
- Allergens
- Animals
6Toxicology and Human Health
- Toxicology
- Toxicology - the study of the adverse effects of
chemicals on human health - Toxicity - a measure of how harmful a substance is
7Toxicology and Human Health
- Toxicology
- Pathways of Exposure
- Inhalation
- Ingestion
- Absorption chemicals on human health
8Toxicology and Human Health
- Toxicology
- Dose and Response
- Dose - the amount of a potentially harmful
substance a person has ingested, inhaled, or
absorbed - Response - the amount of damage to health per
given dose
9Toxicology and Human Health
- Toxicology
- Types of Responses
- Acute Response - an immediate or rapid harmful
reaction to an exposure - Chronic Response - a permanent or long-lasting
reaction to an exposure
10Toxicology and Human Health
- Toxicology
- Factors Affecting Dose and Response
- Bioaccumulation - an increase in the
concentration of a chemical in a specific organ
at a level higher than would normally be expected
11Toxicology and Human Health
- Toxicology
- Factors Affecting Dose and Response
- Biomagnification -an increase in the
concentration of certain slowly-degradable
fat-soluble compounds in organisms at
successively higher trophic levels in a food
chain
12Bioaccumulation and Biomagnification
13Toxicology and Human Health
- Toxicology
- Lethal Dose and Poison
- Median Lethal Dose (LD50) - the amount of a
chemical received in one dose that will kill
exactly 50 of all test animals within a 14 day
test period - Poison - a chemical with an LD50 lt/ 50
milligrams per kilogram of body weight
14Toxicology and Human Health
- Toxicology
- Methods of Determining Toxicity
- Case Reports
- Laboratory Investigations
- Epidemiology
15Toxicology and Human Health
- Chemical Hazards
- Toxic Chemicals - substances that are fatal to gt
50 of test animals at a given concentration
16Toxicology and Human Health
- Chemical Hazards
- Hazardous Chemicals - chemicals that cause harm
by - Being flammable or explosive
- Irritating or damaging skin or lungs
- Interfering/preventing oxygen uptake
- Inducing allergic reactions of the immune system
17Toxicology and Human Health
- Chemical Hazards
- Mutagens - chemicals that cause random mutations
- Radiation
18Toxicology and Human Health
- Chemical Hazards
- Teratogens - chemicals, radiation, viruses that
cause birth defects during development of human
embryo - PCBs
- Thalidomide
- Steroid hormones
- Heavy metals
19Toxicology and Human Health
- Chemical Hazards
- Carcinogens - chemicals, radiation, viruses that
cause/promote growth of malignant tumors
20Toxicology and Human Health
- Chemical Hazards
- Carcinogens
- Major Sources
- Cigarette Smoke (30-40)
- Diet (20-30)
- Occupational Exposure (5-15)
- Environmental Pollutants (1-10)
21Toxicology and Human Health
- Chemical Hazards
- Impacts on the Immune System
- Immune System - cells and tissues that protect
the body from disease by forming antibodies to
invading agents and rendering them harmless
22Toxicology and Human Health
- Chemical Hazards
- Impacts on the Immune System
- Synthetic chemicals
- HIV virus
- Ionizing radiation
23Toxicology and Human Health
- Chemical Hazards
- Impacts on the Immune System
- Weakening of immune system and attack by
allergens, infectious bacteria, viruses,
protozoans
24Toxicology and Human Health
- Chemical Hazards
- Impacts on the Nervous System
- Components of the Nervous System
- Brain
- Spinal Cord
- Nerves
25Toxicology and Human Health
- Chemical Hazards
- Impacts on the Nervous System
- Neurotoxins - chemicals that attack nerve cells
- Chlorinated hydrocarbons
- Organophosphate pesticides
- Formaldehyde
- Heavy metals
- Industrial solvents
26Toxicology and Human Health
- Chemical Hazards
- Impacts on the Endocrine System
- Endocrine System - organs and tissues whose
actions are coordinated by chemical messengers
called hormones
27Toxicology and Human Health
- Chemical Hazards
- Impacts on the Endocrine System
- Hormones control
- Sexual reproduction
- Growth
- Development
- Behavior
28Toxicology and Human Health
- Chemical Hazards
- Impacts on the Endocrine System
- Endocrine Disrupters
- Undersized penises
- Low testosterone levels
- Hyperactivity
- Vaginal cancer
- Malformed testicles
- Retardation
- Endometriosis
29Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Transmissible Disease - a disease caused by a
living organism which can be spread from one
person to another - Pathogens - disease-causing organisms
- Bacteria - single-celled organism
- Viruses - noncellular infectious agent
- Parasites - (tapeworm)
- Protozoa - (amoeba)
30Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Transmissible Disease
- Sources of Exposure
- Air
- Water
- Food
- Body fluids
- Insects
- Non-human carriers (vectors)
31Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Seven Dealiest Transmissible Diseases
- Acute Respiratory Infections
- Bacteria, Viruses (4.7 million deaths)
- Diarheal Diseases
- Bacteria, Viruses (3.1 million deaths)
- Dysentery
32Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Seven Dealiest Transmissible Diseases
- Tuberculosis
- Bacteria (3.1 million deaths)
- Malaria
- Parasitic protozoa (Plasmodium)
- 2.1 million deaths annually
33Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Seven Dealiest Transmissible Diseases
- AIDS
- HIV (1.7 million deaths)
- Hepatitis B
- Virus (1 million deaths)
- Measels
- Virus (1 million deaths)
34Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Seven Dealiest Transmissible Diseases
- LDCs
- Infectious diseases account for 42 of all deaths
annual - 27,000 deaths per day due to infectious diseases
35Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Nontransmissible Diseases
- Cardiovascular disorders
- Cancer
- Diabetes
- Malnutrition
- Bronchitis
- Emphysema
36Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Tuberculosis
- Bacterial Disease
- Airborne droplets of body fluids spread by
coughing, sneezing, talking, singing - 95 of all new cases occur in LDCs
- Rapid reemergence
37Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Tuberculosis
- Causes of reemergence
- Poor screening and control programs
- Development of genetically resistant strains of
bacteria to antibiotics - Population growth and urbanization
- Spread of AIDS
38Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Influenza
- Viral Disease
- Transmitted by body fluids or airborne emissions
- Spanish Flu Epidemic - 1918-1919 killed 30
million people - Ebola
- Transmitted by blood or body fluids
39Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- Rabies
- Viral Disease
- Transmitted by dogs, skunks, raccoons
- AIDS
- HIV - kills bodys immune cells
- Unprotected sex
- Intravenous drug use
- Blood transfusions
40Toxicology and Human Health
- Biological Hazards
- Types of Diseases
- AIDS Facts
- India has highest number of HIV-positive people
- 1996 - 36 million people were infected with HIV
- Heterosexual transmission accounts for 90 of new
HIV infections
41Toxicology and Human Health
- Biological Hazards
- Major Diseases in MDCs
- Epidemiological Transition
- Related to Demographic Transition
- Transmissible diseases supplanted by
non-transmissible diseases - Cardiovascular Disease (39)
- Cancer (24)
- Infectious Diseases (5)
- Accidents (4)
42Toxicology and Human Health
- Biological Hazards
- Sexually-Transmitted Diseases
- Exposure Pathways
- Sexual activity
- Mother to infant during birth
- Intravenous drug use
- Infected blood
43Toxicology and Human Health
- Biological Hazards
- Sexually-Transmitted Diseases
- Bacterial STDs
- Chlamydia
- Gonorrhea
- Syphilis
- Viral STDs
- Genital herpes and warts
- Hepatitis B
- AIDS
44Toxicology and Human Health
- Risk Analysis
- Steps
- Risk Assessment
- Comparative Risk Analysis
- Risk Management
- Risk Communication
45Toxicology and Human Health
- Risk Analysis
- Risk Assessment - Identifying hazards, estimating
the probability that each hazard will occur, and
estimating how many people may suffer serious harm
46Toxicology and Human Health
- Risk Analysis
- Risk Management - determining options about
reducing or eliminating risks - Risk Communication - informing decision makers
and the public about risks
47Toxicology and Human Health
- Risk Analysis
- Risk-Benefit Analysis - an estimate of the short-
and long-term risks and benefits of using a
particular product or technology
48Risk Analysis
49Toxicology and Human Health
- Risk Analysis
- Issues and Limitations
- Depends on toxicology assessments that have
scientific and economic limitations - Who does the analysis?
- Who interprets the results of the analysis?
- How are risk levels set?
- Goals of risk analysis?