Air Pollution: Sources and Health Effects Flashcards
T or F: Air pollution is the contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere
true
[Other definitions of air pollution]
The presence of contaminants or pollutant substances in
the air that interfere with human health or welfare, or
produce other harmful environmental effects.
(Even the normal constituents, when found in excess
amounts, can be considered as air pollution)
The presence of contaminants or pollutant substances in
the air that interfere with human health or welfare, or
produce other harmful environmental effects.
(Even the normal constituents, when found in excess
amounts, can be considered as air pollution)
[Other definitions of air pollution]
Any alteration of the physical, chemical and biological
properties of the atmospheric air, or any discharge thereto of any liquid, gaseous or solid substances that will or is likely to create or to render the air resources of the country harmful, detrimental or injurious to public health, safety or welfare or which will adversely affect their utilization for domestic, commercial, industrial, agricultural, recreational or other legitimate purposes. (Philippine Clean Air Act of 1999)
Any matter found in the atmosphere other than oxygen,
nitrogen, water vapor, carbon dioxide and the inert gases
in their natural or normal concentrations, that is detrimental to health or the environment, which includes but not limited to smoke, dust, soot, cinders, fly ash, solid particles of any kind, gases, fumes, chemical mists, steam and radioactive substances.
What are the events that transpired in the London Smog of December 1952
dense cloud cover blocked solar radiation which caused the temperature to drop rapidly increasing the demand for home heating via coal in furnace which released ash, sulfor oxides and soot causing death from pollution due to small acid droplets easily drawing into lungs
What happened in December 2015 in China?
smog causing red alert for pollution in Beijing; air quality index = 250 (very unhealthy; visibility reduced; happened during winter months (increase in coal fire power plants)
Air Quality Index
Good 0-50 Moderate 51-100 Unhealthy for sensitive groups 101-150 (PH) Unhealthy 151-200 Very Unhealthy 201-300 Hazardous >300
amount of air a person inhales
30 m3 per day (6x more than food and drink consumed)
T or F: exposure to air pollutants is continuous and involuntary
true (why everyone is affected)
most chronic illness in children
asthma (primarily due to dust, dander etc)
The level at which one encounters any substance and is a function of intensity/concentration, frequency (how often the dose is received) and duration (how rapidly the dose is received)
Exposure
Formula for exposure
𝑬𝒙𝒑𝒐𝒔𝒖𝒓𝒆 = 𝑰𝒏𝒕𝒆𝒏𝒔𝒊𝒕𝒚 𝒙 𝑭𝒓𝒆𝒒𝒖𝒆𝒏𝒄𝒚 𝒙 𝑫𝒖𝒓𝒂𝒕𝒊𝒐𝒏
= ℎ𝑜𝑤 𝑚𝑢𝑐ℎ 𝑥 ℎ𝑜𝑤 𝑜𝑓𝑡𝑒𝑛 𝑥 ℎ𝑜𝑤 𝑙𝑜𝑛𝑔
actual amount deposited in the target; different from one person to the other; not the same as exposure
Dose
composition of earth’s atmosphere
- 9%- nitrogen, oxygen and trace levels of carbon dioxide (naturally occurring)
- 001% reactive trace gases (He, Ne, Ar, Kr, Xe)(disequilibrium mixture of chemical species)
Only mechanisms which can account for O2 abundance in the atmosphere
Photosynthesis
Regions of the atmosphere
Troposphere (closest to earth; traps air pollutants; ozone is present)
Stratosphere (ozone layer; influenced by temperature and radiation; filtering layer)
Mesosphere (air is very cool)
Thermosphere (not significant)
T or F: Natural emissions of air pollutants exceed human-produced emissions
TRUE (particulates- 85%, sulfur oxides- 50%, Carbon monoxide 9%)
Examples of natural sources of air pollution
→ Volcanic eruptions release sulfur dioxide into the atmosphere
→ Hydrogen sulfide from biological decay in marshes
→ Emission of particles from wildfires, forest fires and windstorms
− Incomplete combustion releases carbon monoxide
→ Dust storms (mixture of soil, sand, and other debris)
→ Potassium chloride from oceans
Examples of stationary anthropogenic sources of air pollution
→ Point sources – coal-fired power plant smokestacks; easier to control (sulfur dioxide) → Fugitive sources – dirt roads, surface mines, open areas where wind can easily carry dust
→ Area sources – areas of intense industrialization (produce CO2 and greenhouse gases)”
What are mobile anthropogenic sources?
Emissions primarily include nitrogen dioxides and sulfur dioxides but also include primary pollutants
T or F: Man mainly produces nitrogen dioxide
TRUE
these are pollutants emitted directly into the air such as particulates, sulfur dioxide, carbon monoxide, nitrogen oxides
Primary pollutants
These are products of reactions between primary pollutants and normal atmospheric compounds such as tropospheric zone (NO2 + VOCs) - highly reactive
Secondary pollutants
the sources of these pollutants may be limited and industry specific. They are more toxic and carcinogenic than criteria air pollutants
Hazardous Air Pollutants (188 chemicals ie benzene, formaldehyde (in woodworks), cadmium, vinyl chloride (PVC pipes)
ubiquitous air pollutants emitted from mobile and stationary sources (diverse) which poses greatest threat to human health; not very toxic but responsible for air pollution problems; with specific limits set
Criteria Air pollutants (based on clean air act of 1999)
examples of criteria air pollutants
- Suspended particulate matter – TSP and Particulate Matter 10 (meaning, 10 microns)
- Sulfur Dioxide
- Nitrogen Dioxide
- Photochemical Oxidants - Ozone
- Carbon Monoxide
An accumulation of air pollutants causes this
inversion layer (different from normal pattern where ground level air is warmer and air becomes cooler as one rises; dispersing pollution)
specific causes of inversion layer (pollution is trapped close to ground)
temperature fluctuations and radiation
Primary pollutant and contributes to acid deposition
Sulfur dioxide
Sulfur dioxide can be converted to
fine particulate sulfate because of secondary atmospheric reactions
Sources of sulfur dioxide
→ Combustion of coal and diesel fuels (major)
→ Burning of fossil fuels
→ Industrial processes such as petroleum refining
→ Production of paper, cement, aluminum
→ Burning of fuel containing sulfur (e.g. coal)
Nitrogen oxides exists manly as
nitric oxide/nitrogen monoxide (NO) and nitrogen dioxide (NO2)
T or F: nitrogen oxides also contributes to acid deposition
TRUE
This is converted from nitrogen dioxide which is a major contributor to acid rain
NO32-
What can nitrogen dioxide do?
lead to the formation of ozone, other secondary pollutants, and particulate matter