Fine Atmospheric Particles: Do we need to worry about them??. Almost all combustion leads to the formation of fine particles. Mastery of Fire. 400,000 years ago in Europe 100,000 years ago in Africa M. N. Cohne, 1977. Ultimately we learned how to use fire to clear land for crops.
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Mastery of Fire
400,000 years ago in Europe
100,000 years ago in Africa
M. N. Cohne, 1977
Ultimately we learned how to use fire to clear land for crops
In China 2000 years ago the Loess
Plateau was the cradle of ancient Chinese
civilization. Deforestation due to:
Firewoodcollection Charcoal making
Creation of farm land
resulted in a much drier and less
When fire was brought inside the home very large smoke exposures resulted:
Polynuclear Aromatic Hydrocarbons (PAH)
as a class of compounds are considered potential carcinogens
Badger and Spotswood 1960
Chlorinated dibenzo dioxin
Shaub & Tsang, ES&T 1983.
Fresh wood soot in outdoor chambers (0.5 mm scale
A vapor pressure calculation for the liquid vapor for anthracene
Tb= 198 + S DTb ; C14H18
anthracene has10, =CH- , carbons and each carbon = 26.73oK/carbon
It also has 4, =C< at 31.01OK/carbon
Tb = 198 + 267.3 + 124.04 = 589;
Published boiling point is = 613K
At 298K, lnPoL = -12.76; p = 2.87 x10-6atm = 0.0022 torr
rural= 0.5m, high urban 0.35m, Bangkok =0.25m
Comparison of Yamasaki predicted vs measured
Application of this theory
A number of years ago we conducted two wood smoke experiments in our Teflon film chambers to evaluate the stability of 9,10 anthraquinone.
The average chamber temperature for one experiment was 20oC and the other was 38oC. A third experiment was conducted at 30oC, but only filters were analyzed. Data from these experiments are given below.
Three years later it became very important to know the PUF (gas phase) and particle phase distribution of anthraquinone at the 30oC experiment.
It costs, however, 10,000 USD to re-run experiments.
9,10-anthraquinone data in the gas (PUF) and particle (filter) phases
Temp gas (PUF)particle (filter)TSPng/m3ng/m3mg/m3
So what do we do??
lnKy = -a(1/T)+ bTemp is in Kelven
lnKy = -a(1/T)+ b
log Kp = -log Po(L) + const. Kp= part/(gasxTSP)
slope = -1
log Kip= - log iPo(L) +C -log ig
Impact and “advantages” of ammonia “flavor enhancement” on partitioning
The log of the geometric mean is
Indoor activities generate particles
Why is this important???
Why is this important???
2.5 mm particle conc. in mg/m3
Mortality vs. particle exposure
On a mass basis urban fine particles may be more toxic than cigarette smoke
2.5 mm particle conc. in mg/m3
Using their model they could look at the risks associated with:
Adjusted Mortality Risk Ratios for exposure to 24.5 mg/m3 fine particles
The Pope et al. study concludes that:
There are other studies of this type
The latest interpretations do not find the strong relationship that was observed back in 1993, but still report a significant particle exposure and mortality relationship (this is what is in your book chapter, Figure 2-21)
These types of studies
Americans are living longer because the air they breathe is getting cleaner, a new study suggests. The average drop in pollution seen across 51 metropolitan areas between 1980 and 2000 appears to have added nearly five more months to people's lives, according to a study published Wednesday in The New England Journal of Medicine.
Americans are living longer because the air they breathe is getting cleaner, a new study suggests. The average drop in pollution seen across 51 metropolitan areas between 1980 and 2000 appears to have added nearly five more months to people's lives, according to a study published Wednesday in The New England Journal of Medicine (Pope et. al, 2008.)
Many other factors can boost life expectancy, such as increases in income and education and reductions in smoking prevalence, so the researchers used statistical techniques to control for these and other relevant factors.
After this adjustment, they found that the effect of air pollution reduction remained; for every 10 microgram per cubic meter decrease in fine-particulate air pollution, life expectancies rose by about seven months. Pollution levels averaged about 21 micrograms per cubic meter in 1979-1983 and had fallen to an average of 14 micrograms per cubic meter by 1999-2000.
PM2.5 or PM10 inlet
47mm filter holder
on/off digital timer
average 121 ug/m3
2 x % std 8.4%
Chiang Mai Forest Fire Control Unit’s show the following number of fires
PM 2.5 level mg/m3
His + of TA100/plate
Mutagenicity vs. PM 2.5
PM 2.5 levels and air-borne mutagenicity in Chiang Mai ambient air at different monitoring sites in the same month. Bar graph = PM 2.5 level at
= site 1, = site 2, = site 3, = site 4.
Line = mutagenicity at
= site 1, = site 2, = site 3, = site 4, spontaneous revertants have been substracted already.
If the downtown site, for example, “experienced” a slightly higher exposure to diesel exhaust which, is much more mutagenic than wood smoke, the PM levels would appear similar, but the mutagenicity would be influenced by the diesel particles and appear higher.
A high prevalence of asthma in children living in Chiang Mai has been reported.
At the present time, however, it is difficult without further study to know if open burning is exacerbating the asthma problem in Chiang Mai.
It would seem prudent, given the high fine particle concentrations, to curtail open burning as much as possible. Future studies should also attempt to identify compounds in Chiang Mai air that are potentially toxic to human health so that these may be used as bench marks for future control strategies.