Outdoor Exposures

Question 1

Who determines the Air Quality Index (AQI)?

Answer 1

the EPA, AQI is a color-coded and numeric scale (6 levels), Green (0) - Maroon (500)

Question 2

What are some major sources of air pollution?

Answer 2

Major sources: power plants, refineries, transportation

Smaller sources: nail salons, dry cleaners, auto body shops

Question 3

Classification of particulate matter(PM): PM10

Answer 3

All particles ≤ 10 microns. Anything bigger usu. not deposited in lungs

Question 4

Classification of particulate matter(PM): PM2.5

Answer 4

• fine fraction particles
• Directly emitted from combustion sources and formed secondarily from gaseous precursors of sulfur dioxide, nitrogen oxides, or organic compounds
• Remains in atmosphere days to weeks and travels through atmosphere hundreds and thousands of km.
• Main cause of reduced visibility (haze) in the U.S.

Question 5

Classification of particulate matter(PM): PM10-2.5

Answer 5

• coarse fraction particles

- Tend to deposit to the earth w/in mins to hrs and w/in tens of km from emission source

Question 6

Classification of particulate matter(PM): Ultrafine

Answer 6

• all particles < 0.1 microns

- May leave lung and travel thru blood to other organs, including heart

Question 7

Define acid rain

Answer 7

Any form of wet precipitation with ph <5.6

Question 8

What causes acid rain and what are the effects of it?

Answer 8

• Caused by fossil fuel emissions: S and NOs combine w/ H20 in the atmosphere
• When the environment cannot neutralize the acid deposited → damage! Such as accelerating the decay of buildings, changing aquatic ecosystems, and loss of nutrients in forest soils

Question 9

Define smog

Answer 9

• Combination of words smoke and fog
• Mixture of air pollutants including gases and fine particles often seen as a brownish-yellow or grayish-white haze in the air

Question 10

How does smog form and from what?

Answer 10

• Formed in Earth’s lower atmosphere when pollutants from cars, refineries, power plants, etc. react chemically in the presence of sunlight
• Components: Ground level ozone, Nitrogen oxides, Volatile organic compounds (VOCs), Sulfur dioxide and Particulate matter

Question 11

What are the 6 criteria pollutants?

Answer 11

Pollutants the Clean Air Act requires the EPA to set standards for:

• Ground level ozone
• Nitrogen oxides
• Polycyclic aromatic hydrocarbons (PAH)
• Benzene
• Carbon Monoxide
• Particulate Matter (particles of soot, dust, or other matter including small droplets of liquids)

Question 12

How is ground level ozone created?

Answer 12

• Not emitted directly into the air but created by chemical reactions between oxides (NOx) and Volatile Organic Compounds (VOCs) in the presence of sunlight (i.e. ozone is a secondary pollutant)

Question 13

How does carbon monoxide exposure impact health?

Answer 13

RBCs can pick up CO quicker than O2. If there is a lot of CO around, they may replace the oxygen in the blood with CO → tissue necrosis→ death

Question 14

What symptoms are associated with carbon monoxide poisoning?

Answer 14

HA, Dizziness, Weakness, N/V, Chest pain, Confusion

HIGH LEVELS: LOC and death

Question 15

What is the main cause of haze?

Answer 15

PM2.5 = fine fraction particles

Question 16

What is the primary cause of acid rain?

Answer 16

Sulfur Dioxide (colorless gas, smells like burnt matches)

Question 17

What are CFCs?

Answer 17

Chlorofluorcarbons = compound consisting of chlorine, fluorine, and carbon.

Question 18

Where are CFCs commonly used in and why are we concerned?

Answer 18

Commonly used in: Refrigerants, Solvents, Foam blowing agents
Concern: Very stable in the atmosphere, moves to the stratosphere and is broken down by strong UV light which releases the chlorine atoms that break down the ozone layer

Question 19

What is being used to replace CFCs?

Answer 19

HCFC = Hydrochlorofluorocarbons

• EPA efforts to reduce the amount of ODS (Ozone Depleting Substances) produced or imported into the U.S.
• Contains chlorine and thus depletes the ozone but less so than CFCs

Question 20

Notable characteristic organochlorine pesticides and what are some examples?

Answer 20

Commonly used in the past but many have been removed from the market because of their health and environmental effects and their persistence
ex: DDT, Chlordane, Dieldrin, Heptachlor

Question 21

Notable characteristics of organophosphates pesticides?

Answer 21

• Developed during the early 19th century but main effects were realized in 1930s; used in WWII as nerve agents
• Popular after ban of organochlorines in the 1970s
• acetylcholinesterase inhibitor
• Higher toxicity than carbamates

Question 22

Notable characteristics of carbamate pesticides?

Answer 22

• Salts or esters or carbamic acid

- acetylcholinesterase inhibitor

Question 23

What is the health concern regarding fertilizers?

Answer 23

Nitrate alters the iron in hemoglobin from the ferrous to the ferric state, which forms methemoglobin (abN hemoglobin) → blood loses its ability to carry oxygen to tissues.

Question 24

What are the 2 classes of acetylcholinesterase inhibitors that are pesticides?

Answer 24

Organophosphates and Carbamates