Environmental Lecture 1

Question 1

Environmental and Occupational Health Encompasses?

Answer 1

Diagnosis
Treatment
Prevention (of injuries and illness related from exposure to exogenous chemical or physical agents)

Question 2

Environmental and Occupational Health Exposure?

Answer 2

Workplace

Therapeutic and nontherapeutic drug consumption

Question 3

Recognition Environmental and Occupational Health Diseases?

Answer 3

Accidents, illness, premature deaths

- Occur: mining, ag, construction, transportation and public utility

Question 4

Environmental and Occupational Health ratios?

Answer 4

Injuries: 7400/100,000
Death: 4.8/100,000

Question 5

Health Effects of Climate Changes

Answer 5

Human activity:

• Since 1960, 0.6 C
• Sea level has risen 1-2 mm/year
• Increase in carbon dioxide, methane, ozone (greenhouse effects)

Question 6

Diseases related to climate changes?

Answer 6

Cardiovascular, cerebro-vascular, and respiratory disease (heat waves, air pollution)
Gastroenteritis and infectious disease epidemics (water and food contamination –> floods, disruption of clean water supplies)
Vector-borne infectious disease (malaria, west nile infection)
Malnutrition (disruption of crops)

Question 7

Toxicity of chemical agents

Answer 7

100,000 different chemicals in commercial use in the US

• 10% of 600 tested cause cancer
• Waste sites: 4 billion pounds of toxic chemicals (72 million pounds are carcinogens)

Question 8

Regulatory Agencies

Answer 8

Environmental Protection Agency
FDA
Occupational Safety and Health Administration
Consumer Products Safety Commision

Question 9

Environmental Protection Agency

Answer 9

Regulates exposure to pesticides, toxic chemicals, water, and air pollutants and hazardous waste

Question 10

FDA

Answer 10

Regulates drugs, medical devices, food additives and cosmetics

Question 11

Occupational Safety and Health Administration

Answer 11

Mandates that employers provide safe working conditions for employees

Question 12

Consumer Products Safety Commisions

Answer 12

Regulates all other products sold for use in homes, schools or recreations

Question 13

Physicians

Answer 13

Should be familiar with regulatory agencies in US

- Explain the evidence in nontechnical terms

Question 14

Health care providers

Answer 14

Cousel patients on prevention

tobacco smoking prevention 80-90% lung cancer

Question 15

Toxicology

Answer 15

Scientific discipline that studies the distribution, effects and MOA of toxic agent

Question 16

Toxicity

Answer 16

Degree to which a drug is able to produce illness or damage to an exposed organism
Depends on: inherent strucuture/properties and dose

Question 17

Dose-Response Curve

Answer 17

Subthreshold dose: safe dose
Threshold dose: begin response
Ceiling effect: plateau

Question 18

Xenobiotics

Answer 18

• “Foreign agents”
  Exogenous chemicals in the environment (air, water, food and soil)
  Absorbed into the body through inhalation, ingestion and skin contact

Question 19

Xenbiotic metabolism non-toxic

Answer 19

Phase 1 (hydrolysis, reduction, oxidation)
Phase 2 (sulfation, methylation, conjugation) --> more water soluble leading to elimination

Question 20

Xenobiotic metabolism toxic

Answer 20

Nontoxic metabolite –> reactive metabolite –> effects on cellular molecules (enzymes, receptors, etc) –> toxicity

Question 21

Personal exposures

Answer 21

Tobacco Use
Alcohol Abuse
Drug Abuse

Question 22

Tobacco Use

Answer 22

Cigarettes, cigars, pipes, snuff
Deaths: 440,000 per year
Diseases: 10,000,000 cases of chronic diseases, increased morality and morbidity (lung cancer, cardiovascular disease, chronic respiratory disease)

Question 23

Cigarette smoke consists of two phases?

Answer 23

Particulate phase (tar)
4,000 constituents (43 are carcinogens)
Gas phase
- chemical and metal (arsenic, nickel and cadmium) carcinogens, tumor promoters (acetaldehyde and chromium), irritants (NO2, formaldehyde) and cilia toxins (H cyanide), CO (binds hb --> less O2 delivery), and nicotine (alkaloid readily crosses BBB, stimulates nicotine receptors in the brain)

Question 24

Tobacco addiction

Answer 24

Increases: heart rate, bp, coronary artery blood flow, contracitility and cardiac output

Question 25

Routes of delivery for smoke

Answer 25

Mucous membranes Swallowed in salvia Alveolar capillary bed --> bloodstream

Question 26

Bad stuff of smoke

Answer 26

``` Act on distant target organs --> cause variety of systemic disease Common disease (lung cancer, artery disease, etc) Effects of fetus: hypoxia --> low birth weight, prematurity, spontaneous abortions, complication at delivery Second hand smoke ```

Question 27

Alcohol abuse

Answer 27

More than 10 million chronic alcoholics More than 100,000 deaths Results in psychological and physical dependence Effects: depends on ethanol consumed/unit of body weight + time period in which it is ingested

Question 28

Blood concentration

Answer 28

Amount exhaled depnds on blood concentration - 80-100 g/dL --> DUI 2 oz of ethanol in a 70 kg persons ( 15 oz of wine, 3 12 oz beers, 4-5 oz 80-proof whiskey)

Question 29

Occasional drinkers

Answer 29

200 mg/dL --> drowsiness 300 mg/dL --> stupor >300 mg/dL --> coma, respiratory arrest, consequent death

Question 30

Habitual drinkers

Answer 30

Up to 700 mg/dL --> accelerated metabolism, induction of CYPs

Question 31

Metabolism of ethanol

Answer 31

Liver Ethanol to acetaldehyde via ADH (alcohol DH) - enter microsomes via CYP 2E1 - enters peroxisomes via catalase - enter mitochondria via acetaldehyde DH into acetic acid

Question 32

Alcohol oxidation by ADH

Answer 32

Decrease NAD and increases NADH - NAD required for fatty oxidation in liver and conversion of lactate to pyruvate - fatty acid and lactic acidosis in alcoholics

Question 33

Metabolism of CYP2E1 produces

Answer 33

ROS - lipid peroxidation of cell membrane -- cellular injury

Question 34

Chronic alcoholism causes

Answer 34

cirrhosis of liver, bleeding from gastric ulcers, thiamine deficiency

Question 35

Alcohol in pregnancy

Answer 35

Fetal alcohol syndrome

Question 36

Laryngeal and esophageal cancer

Answer 36

Due to acetaldehyde DNA adducts

Question 37

Acetaldehyde

Answer 37

Carcinogen that can attack the DNA and cause cancer

Question 38

Asians

Answer 38

Genetic polymorphism: aldehyde DHase that affects ethanol metabolism: Low ALDH activity --> increased acetaldehyde (facial flushing syndrome)