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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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400,000 years ago in Europe
100,000 years ago in Africa
M. N. Cohne, 1977
Plateau was the cradle of ancient Chinese
civilization. Deforestation due to:
Firewood collection 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:
as a class of compounds are considered potential carcinogens
Badger and Spotswood 1960
Chlorinated dibenzo dioxin
Shaub & Tsang, ES&T 1983.
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
Phen Pyrene BaP
8x10-4 6x10-5 2x10-7
10g/m3 0.2 2 91
100g/m3 3.1 23 99
500g/m3 18 68 100
rural= 0.5m, high urban 0.35m, Bangkok =0.25m
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) TSP ng/m3 ng/m3 mg/m3
38oC 228 105 0.512 20oC 38 381 0.366 30oC ? 440 0.832
So what do we do??
lnKy = -a(1/T)+ bTemp is in Kelven
lnKy = -a(1/T)+ b
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
2.5 mm particle conc. in mg/m3
Adjusted Mortality Risk Ratios for exposure to 24.5 mg/m3 fine particles
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)
47mm filter holder
on/off digital timer
2 x % std 8.4%
Chiang Mai Forest Fire Control Unit’s show the following number of fires
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.