Class Notes (839,150)
Canada (511,218)
PHAR 100 (175)


6 Pages

Pharmacology and Toxicology
Course Code
PHAR 100
Hisham Elbatarny

This preview shows pages 1 and half of page 2. Sign up to view the full 6 pages of the document.
Environmental Toxicants - Part 1 Acute versus Chronic Toxicity Acute toxicity • single exposure • often large dose ◦ e.g. chemical spill Chronic toxicity • repeated exposure • prolonged time period • small doses ◦ e.g. eating contaminated food Acute toxicity • usually more obvious effects • acute effects often different from chronic effects ◦ e.g. aflatoxin B1 (common food contaminant) ▪ acute: liver necrosis, liver failure, death ▪ chronic: liver cancer Air Pollutants • 1273 – first antipollution law • early 20th century – automobiles • 1952 – “killer smog” in London, England ◦ dense fog + smoke, SO2, particulates ◦ 4,000 deaths ◦ bronchitis, pneumonia, etc. ◦ demonstrated the lethality of air pollution • 1956 – Clean AirAct Major Air Pollutants • gaseous: carbon monoxide (CO), hydrocarbons, hydrogen sulfide, nitrogen oxides, ozone, sulfur oxides, carbon dioxide (CO ) 2 • particulate matter: mixture of tiny particles that are composed of organic, inorganic and biological materials; solids, liquid droplets Sources of Air Pollutants Natural • volcanoes • forest and prairie fires • dust storms • trees, plants Human-Made • anthropogenic: of, relating to, or resulting from the influence of human beings on nature • three main sources Anthropogenic Air Pollutants 1. Combustion of fossil fuels (heating and power) • coal, oil: contain sulfur, sulfur oxides released, acid rain • nitrogen oxides • carbon monoxide (CO): incomplete combustion ◦ efficient combustion: high CO /CO 2 2. Automobile Exhaust • smoke, lead particles, CO, nitrogen oxides, hydrocarbons • late 20th century → decrease emissions 3. Industrial Processes • acids, solvents, metals, etc. Human Health Effects from Air Pollutants • chemical irritation of respiratory tract • particularly susceptible: ◦ very young children ◦ elderly ◦ people with cardiorespiratory diseases ▪ asthma, emphysema, heart disease • most cases: particulates and sulfur oxides responsible Tobacco Smoke: History • tobacco - dried leaves of plant Nicotiana tabacum • Western world introduced in late 15th century • mid 20th century advertising concentrated on social advantages of smoking particular brands • 1964 – U.S. Public Health Service released comprehensive report detailing adverse effects of cigarette smoking Tobacco Smoke: History • 1990’s: Tobacco taxation and smuggling “hot” political issues ◦ successful law suits against manufacturers • 1997: Creation of the TobaccoAct • today: ◦ at least nine provinces suing major tobacco companies ◦ Oct 16th 2012, smoking bylaw in Kingston Tobacco Smoke: Effects on Human Health • adverse effects due to nicotine, CO, tar • > 45,000 deaths/year attributable to smoking in Canada • cigarette smoking causes ~ 30% of all cancers (Canadian Cancer Society) ◦ more than 4000 chemicals in cigarette smoke, at least 60 are known carcinogens ◦ main increased risk is lung cancer ◦ mouth, esophagus, bladder, pancreas, etc. Tobacco Smoke: Cardiovascular Effects • ↑ platelet activation (clotting) • damage to blood vessel lining • changes in lipoproteins (↑ LDL, ↓ HDL) • nicotine effects (see nicotine lecture) • CO: ↓ O t2 tissues, including heart ◦ heart’s O supply/demand affected 2 Tobacco Smoke: Cardiovascular Effects • CoronaryArtery Disease: ↑ risk of heart attack • Cerebrovascular Disease: ↑ risk of stroke due to clot or bleeding • Peripheral Vascular Disease: ↓ blood flow to extremities Tobacco Smoke: Chronic Obstructive Pulmonary Disease (COPD) • Smoking ◦ tar content ↑ action of inflammatory cells ◦ direct chemical damage • Chronic Bronchitis ◦ airways ◦ persistent cough • Emphysema ◦ tissue destruction in peripheral lung ◦ breathl
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.