Lecture 12 Review Questions and Answers (air pollution) Flashcards
How is ground level ozone created? why is it called a secondary pollutant (know the difference)
Chemical reactions between Nitrogen oxide and VOCs in the presence of heat and sunlight occur at the ground level to create ground level ozone
Primary pollutant: harmful substance that is emitted directly into the atmosphere
Secondary pollutant: when primary air pollutant reacts with substances in the atmosphere to form harmful substances
What are primary sources of VOCs?
Paints, paint strippers and car exhaust
What is particulate matter? where does it come from?
small particles of dust, ash, soot or any other visible material
What size of particulate matter is the most threatening to human health?
PM10: particles less than 10 microns in diameter
PM 2.5: particles less than 2.5 microns in diameter
The smaller particles are more dangerous because they can be inhaled and reach the lung (bigger ones get trapped in mucous)
Environmental concern around sulfur dioxide and nitric acid?
Both released into atomosphere and combine with water to form acid rain. Acid rain kills plant life, pollutes rivers and stream and erode stonework. Plants cannot absorb nutrients properly from acidic soil, fish and amphibians have specific pH ranges they can tolerate.
what is the evidence that air pollutants have an effect on human health?
Harvard six cities study: looked at long term health outcomes analyzed in relation to city-specific air pollution controlling for confounding variables like smoking, income, race and occupation. Found that as particle concentration increased, there was an almost directly increase in death rates. Increased mortality for cities with high long-term PM concentrations.
what are challenges to studying air pollution effect on human health?
Hard to show direct dose-response relationship
Pollutants tend to co-vary and so it is hard to distinguish effects
You can demonstrate association between O and E, but not cause and effect
Must control for confounding factors
exposure assessment is ecologic
know the two primary designs of epi studies to investigate air pollution effects
Time series of acute effects
Cohort and cross-sectional studies of chronic effects (harvard 6 cities)
What are some commonly used biomass fuels?
Agric waste, wood, cow dug and seaweed, dried leaf, hay
Where is traditional biomass typically used around the world?
Africa, india, South Asia
Why is biomass a low efficiency energy system?
poor conversion of fuel energy to heat
poor transfer of heat to pot due to poor insulation and lack of contact of hot gases with pot
How is biomass combustion harmful to human health?
creates large volumes of shitty products due to incomplete combustion
two populations affected?
Women: COPD, cancer, blindness and heart disease
Kids: Pneumonia, Asthma, low birth weight, cognitive impairment
2 mipediments to fixing this problem
under recording, lots of data from high exposure to smoke from smokers, lots of data from air pollution study, no data in the middle
possible solutions to mitgate
Switch to cleaner stove with clean fuel, have chimneys. Trade off between cheap stove with modest exposure reduction and expensive stoves with large reduction