Скачать презентацию l Fine Atmospheric Particles Do we need Скачать презентацию l Fine Atmospheric Particles Do we need

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 l. Fine Atmospheric Particles: Do we need to worry about them? ? l. Fine Atmospheric Particles: Do we need to worry about them? ?

 l. Almost all combustion leads to the formation of fine particles l. Almost all combustion leads to the formation of fine particles

Mastery of Fire 400, 000 years ago in Europe 100, 000 years ago in 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 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 In China 2000 years ago the Loess Plateau was the cradle of ancient Chinese civilization. Deforestation due to: Firewood collection Charcoal making Creation of farm land Brick making resulted in a much drier and less productive climate

 • North American Indians used to burn forested areas to promote the growth • North American Indians used to burn forested areas to promote the growth of food ”sprouts” • In Mexico deforestation often lead to soil erosion and drier climates (8001400 before present-BP)

When fire was brought inside the home very large smoke exposures resulted: i. These When fire was brought inside the home very large smoke exposures resulted: i. These exposures are often much higher in the developing world than in the industrialized world i. Women tend to spend more time around unvented fires than men

i. In Nepal females and their very young children receive much higher exposures to i. In Nepal females and their very young children receive much higher exposures to indoor fires than males (Kirk Smith, 1983) i. Average cooking time is 2. 8 hours i. Prevalence of chronic bronchitis is related to hours spent near the stove

Exposures are indoors as well as outdoors Picture by Kirk Smith, India, early 1980 Exposures are indoors as well as outdoors Picture by Kirk Smith, India, early 1980 s

After a few hours After a few hours

Acute Respiratory Infections/6 month in Rural Nepal Infants vs. time Near Stove (M. R. Acute Respiratory Infections/6 month in Rural Nepal Infants vs. time Near Stove (M. R. Panday, 1984)

Acute Respiratory Infections in Rural Nepal Infants vs. time Near Stove (M. R. Panday, Acute Respiratory Infections in Rural Nepal Infants vs. time Near Stove (M. R. Panday, 1984)

Acute Respiratory Infections in Rural Nepal Infants vs. time Near Stove (M. R. Panday, Acute Respiratory Infections in Rural Nepal Infants vs. time Near Stove (M. R. Panday, 1984)

Comparative Particulate Concentrations in g/m 3 • • • U. S. Standard (PM 2. Comparative Particulate Concentrations in g/m 3 • • • U. S. Standard (PM 2. 5) 65 Sydney (1996) ~25 Traffic- Denmark 60 London Smog (1952) 4, 500 Muese, Belgium 12, 500 Indian village 1, 000 (Indoors ) 56, 000 • Malaysia (1997, PM 2. 5) 800 • Thailand (1998, PM 2. 5) 300

Combustion forms a host of toxics that are associated with soot particles • Polynuclear Combustion forms a host of toxics that are associated with soot particles • Polynuclear aromatic hydrocarbons (PAH) • Chlorinated dioxins and furans • Aldehydes and carbonyl compounds

Polynuclear Aromatic Hydrocarbons (PAH) as a class of compounds are considered potential carcinogens Polynuclear Aromatic Hydrocarbons (PAH) as a class of compounds are considered potential carcinogens

Combustion Formation of PAH Badger and Spotswood 1960 Combustion Formation of PAH Badger and Spotswood 1960

Combustion Formation of Dioxins from Polychlorinated phenol OH C lx OH. Flame C lx Combustion Formation of Dioxins from Polychlorinated phenol OH C lx OH. Flame C lx OH Polychlorinated Phenol + . O C ly C lx O + OH O C ly OH C lx O C ly Chlorinated dibenzo dioxin Shaub & Tsang, ES&T 1983.

Fresh wood soot in outdoor chambers (0. 5 mm scale Fresh wood soot in outdoor chambers (0. 5 mm scale

Many of these compounds exist as a free gas and on particles. This influences: Many of these compounds exist as a free gas and on particles. This influences: • how they will be deposited on the earth's surface • the types of chemical reactions they can undergo • the route by which they enter the food chain and are sorbed or deposited in the lungs

Gas Particle Partitioning toxic gas particle Gas Particle Partitioning toxic gas particle

Langmuirian Adsorption (1918) gas surface • = fraction of total sites occupied • Rateon= Langmuirian Adsorption (1918) gas surface • = fraction of total sites occupied • Rateon= kon (Pg) (1 - ); • Rateoff= koff ; • kon/koff= Keq

Langmuirian Isotherm • • if Keq Cgas<< 1; = Keq Cgas Langmuirian Isotherm • • if Keq Cgas<< 1; = Keq Cgas

Junge (1977) • · = jcj /(Po + jcj) · = fraction in aerosol Junge (1977) • · = jcj /(Po + jcj) · = fraction in aerosol phase · Po= sat. vapor pressure of the pure compound · j = conc. of aerosol surface (cm 2/cm 3) · cj =const, b. BET, moles of sites/cm 2, temp · cj=RTNse(Qi-Ql)/RT

A vapor pressure calculation for the liquid vapor for anthracene Tb= 198 + S A vapor pressure calculation for the liquid vapor for anthracene Tb= 198 + S DTb ; C 14 H 18 anthracene has 10, =CH- , carbons and each carbon = 26. 73 o. K/carbon It also has 4, =C< at 31. 01 OK/carbon Tb = 198 + 267. 3 + 124. 04 = 589; Published boiling point is = 613 K At 298 K, ln. Po. L = -12. 76; p = 2. 87 x 10 -6 atm = 0. 0022 torr

Percent in the Aerosol Phase at Different Aerosol Concentrations (25 o. C) Phen Ba. Percent in the Aerosol Phase at Different Aerosol Concentrations (25 o. C) Phen Ba. P 8 x 10 -4 10 g/m 3 100 g/m 3 500 g/m 3 Pyrene 6 x 10 -5 2 x 10 -7 0. 2 3. 1 18 2 23 68 91 99 100 rural= 0. 5 m, high urban 0. 35 m, Bangkok =0. 25 m

Yamasaki et al. (1982) • Langmuirian adsorption • • Assumes total # sites TSP Yamasaki et al. (1982) • Langmuirian adsorption • • Assumes total # sites TSP (particle conc) • log Ky = -a(1/T)+ b

Yamasaki (1982) • Collects Hi-vol filters+PUF • Analyzes for PAHs filter Ba. A log Yamasaki (1982) • Collects Hi-vol filters+PUF • Analyzes for PAHs filter Ba. A log Ky PUF 1/Tx 1000

Yamasaki’s relationship • This gives a log Ky = -a(1/T)+ b which is compound Yamasaki’s relationship • This gives a log Ky = -a(1/T)+ b which is compound specific • Ideally from the regression values of a and b, one can estimate the partitioning of a given compound in any atmosphere at a given temp. and TSP

Comparison of Yamasaki predicted vs measured Comparison of Yamasaki predicted vs measured

Application of this theory Application of this theory

A number of years ago we conducted two wood smoke experiments in our Teflon 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 20 o. C and the other was 38 o. C. A third experiment was conducted at 30 o. C, but only filters were analyzed. Data from these experiments are given below.

UNC 3 Teflon 25 m Film Chambers UNC 3 Teflon 25 m Film Chambers

Three years later it became very important to know the PUF (gas phase) and Three years later it became very important to know the PUF (gas phase) and particle phase distribution of anthraquinone at the 30 o. C 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 9, 10 -anthraquinone data in the gas (PUF) and particle (filter) phases Temp gas (PUF) ng/m 3 particle (filter) ng/m 3 TSP mg/m 3 38 o. C 228 105 0. 512 20 o. C 38 381 0. 366 30 o. C ? 440 0. 832 So what do we do? ? ln. Ky = -a(1/T)+ b Temp is in Kelven

PAHGas PAHpart ln. Ky = -a(1/T)+ b PAHGas PAHpart ln. Ky = -a(1/T)+ b

log Kp = -log Po(L) + const. Kp= part/(gasx. TSP) slope = -1 log log Kp = -log Po(L) + const. Kp= part/(gasx. TSP) slope = -1 log Kp Ambient data of Pankow and Bidleman log Po(L) PAHs, alkanes chlorinated organics

For liquid like particles partitioning coefficient, Kp, is: • Kip = 760 RT fomx For liquid like particles partitioning coefficient, Kp, is: • Kip = 760 RT fomx 10 -6/{i. PLtorr ig MWavg} log Kip = - log i. Po(L) +C -log ig • C= log [fom (7. 501 RT)/ (106 Mwom)] · fom = fraction of particle organic mass · Mwom = avg. Mw of om in the particle

Calculating Activity Coefs, ig • RT lnigom= i. V[(omdd - idd)2 +ib(omdp - idp)2 Calculating Activity Coefs, ig • RT lnigom= i. V[(omdd - idd)2 +ib(omdp - idp)2 + ib(omdh - idh)2] + RT [ln(i. V/Vom) +1 - i. V/Vom] • Vom is the molar volume of the mix hds are solubility parameters hdd = S Fd, j / i. V

Partitioning & uptake by the lungs • Nicotine (Pankow’s group) Partitioning & uptake by the lungs • Nicotine (Pankow’s group)

Uptake by the lungs (Nicotine) • Under normal circumstances Nicotine can exist as a Uptake by the lungs (Nicotine) • Under normal circumstances Nicotine can exist as a neutral “free base” or as a protonated mono or di-acid and will appear predominately in the particle phase. • Typically cigarette smoke has p. H values ³ 3 and much of the nicotine exists in the acidified form on particles.

Nicotine • The acidified form can not partition between the gas and particle phase. Nicotine • The acidified form can not partition between the gas and particle phase. • If ammonia is added to the tobacco smoke, “as a flavor enhancement”, the p. H increases moving the equilibrium on the particles from the mono-acid to the neutral form.

Impact and “advantages” of ammonia “flavor enhancement” on partitioning • In the neutral form Impact and “advantages” of ammonia “flavor enhancement” on partitioning • In the neutral form nicotine can partition to the gas phase. • neutral nicotine can then be readily absorbed by the wet surface of the inner lung (Pankow’s group) • loss of nicotine to the lungs “pulls” more nicotine off the particles

What are aerosols? • Aerosols are simply airborne particles • They can be solids What are aerosols? • Aerosols are simply airborne particles • They can be solids or liquids or both • They can be generated from some of the following sources:

What are aerosols? • Aerosols are simply airborne particles • They can be solids What are aerosols? • Aerosols are simply airborne particles • They can be solids or liquids or both • They can be generated from some of the following sources: 1. combustion emissions 2. atmospheric reactions 3. re-entrainment

What are some of the terms used to describe aerosols? What are some of the terms used to describe aerosols?

What are some of the terms used to describe aerosols? • Diameters are usually What are some of the terms used to describe aerosols? • Diameters are usually used to describe aerosol sizes, but aerosols have different shapes.

Often particles are sized by their aerodynamic diameter • The aerodynamic diameter of a Often particles are sized by their aerodynamic diameter • The aerodynamic diameter of a particle is defined as the diameter of an equivalent spherical particle (of unit density) which has the same settling velocity. • It is possible to calculate the settling velocity of a spherical particle with a density =1

 • Density = mass/volume Density. H 20 = 1 gram/cm 3= 1 • • Density = mass/volume Density. H 20 = 1 gram/cm 3= 1 • Terminal Settling velocity (Vs ) is the rate that a particle falls due to gravity

Often when we measure particles they cover a large range of sizes Often when we measure particles they cover a large range of sizes

The normal distribution The normal distribution

A Log normal distribution is often applied to the size data by plotting the A Log normal distribution is often applied to the size data by plotting the logs of the particles size vs frequency The log of the geometric mean is log diameter

The log normal distribution The log normal distribution

Aerodynamic diameters of some particles • • tobacco smoke ammonium chloride flour dust fogs Aerodynamic diameters of some particles • • tobacco smoke ammonium chloride flour dust fogs pollens talc photochemical aerosols 0. 25 mm 0. 1 15 - 20 1 - 5 15 - 70 10 0. 01 -1

Aerosol exposures l Indoors l Outdoors l Cars l Work place Aerosol exposures l Indoors l Outdoors l Cars l Work place

Aerosol exposures l Indoors (90% of our time) – ventilation systems – mechanically re-entrain Aerosol exposures l Indoors (90% of our time) – ventilation systems – mechanically re-entrain particles (dust mites) – cooking

Indoor activities generate particles Indoor activities generate particles

Activities that generate aerosols in Kamens home Activities that generate aerosols in Kamens home

Cooking stir-fried vegetables: Kamens house, 1987, EAA data Cooking stir-fried vegetables: Kamens house, 1987, EAA data

Vacuuming in Kamens House Vacuuming in Kamens House

Kamens house at night Kamens house at night

How do particle sizes distribute in the atmosphere? ? How do particle sizes distribute in the atmosphere? ?

How do particle sizes distribute in the atmosphere? ? . 3 -. 8 um How do particle sizes distribute in the atmosphere? ? . 3 -. 8 um 4 -10 um

Particle samplers often collect particles smaller than a given size • PM 10 is Particle samplers often collect particles smaller than a given size • PM 10 is defined as particles with diameters < 10 mm. • It is measured in units of mg/m 3 , typically by pulling air through filters. • PM 2. 5 is defined as particles with diameters < 2. 5 mm

 • The choice of measuring at exactly PM 10 or PM 2. 5 • The choice of measuring at exactly PM 10 or PM 2. 5 is somewhat arbitrary • Some people argue for a PM 1. 0 • Until recently only PM 10 has been measured in Thailand

Why is this important? ? ? Why is this important? ? ?

Why is this important? ? ? Naso-oropharyngo. Tracheobronchial Alveolar Why is this important? ? ? Naso-oropharyngo. Tracheobronchial Alveolar

Where do particles deposit? ? i. Large particles deposit in the Naso-oro-pharyngo- region i. Where do particles deposit? ? i. Large particles deposit in the Naso-oro-pharyngo- region i. Very fine particles (< 0. 01 mm) deposit in the Tracheo-bronchial i. About 15 -20% of the particles between 0. 1 and 1 mm deposit in the Alveolar region

How do particles distribute in the atmosphere? ? . 3 -. 8 um 4 How do particles distribute in the atmosphere? ? . 3 -. 8 um 4 -10 um

Aerodynamic diameters of some particles • • tobacco smoke ammonium chloride flour dust fogs Aerodynamic diameters of some particles • • tobacco smoke ammonium chloride flour dust fogs pollens talc photochemical aerosols Car exhaust 0. 25 mm 0. 1 15 - 20 1 - 5 15 - 70 10 0. 01 -1 0. 1 - 0. 3

u. Urban Particle Exposure and its Association with Mortality and Morbidity u. Urban Particle Exposure and its Association with Mortality and Morbidity

Killer Particles Killer Particles

Recent Particle Health Studies • Dockery et al. , N. Eng. J. Med, vol Recent Particle Health Studies • Dockery et al. , N. Eng. J. Med, vol 329, p 1753, 1993) • looked at 6 American cities with different annual PM 2. 5 concentrations • From 1974 to 1990, they followed 8111 males and females. • Subjects were 25 -74 years old

Mortality rates were estimated from: • Survival times (date of death minus the start Mortality rates were estimated from: • Survival times (date of death minus the start date for that person in the study) • Raw mortality rates are computed, for each city, which are the number of deaths/year/100, 000 people • These were adjusted for smoking, education, body mass index, and other risk factors

Mortality vs. particle exposure 1. 3 1. 2 mortality 1. 1 ratio 1. 0 Mortality vs. particle exposure 1. 3 1. 2 mortality 1. 1 ratio 1. 0 10 20 30 40 2. 5 mm particle conc. in mg/m 3 • On a mass basis urban fine particles may be more toxic than cigarette smoke

Another Study by (Pope et al. , Am J. Crit. Care Med. , vol Another Study by (Pope et al. , Am J. Crit. Care Med. , vol 151, p 669, 1995) • looked at 151 cities with different annual PM 2. 5 concentrations in 1980 • 552, 138 mostly white adults

Deaths/10000 2. 5 mm particle conc. in mg/m 3 Deaths/10000 2. 5 mm particle conc. in mg/m 3

 • Used a Cox multiple regression analysis proportional hazards model • Fleming, T. • Used a Cox multiple regression analysis proportional hazards model • Fleming, T. R. and D. P Harrington Counting Processes and Survival Analysis. John Wiley, New York, 1991 • SAS Technical Report P-217; SAS/STAT Software: The PHREG Procedure. Version 6; SAS Institute, Cary NC, USA

Using their model they could look at the risks associated with: • • • Using their model they could look at the risks associated with: • • • age sex race cigarette smoking passive smoke exposure body mass alcohol intake education occupational exposure

Adjusted Mortality Risk Ratios for exposure to 24. 5 mg/m 3 fine particles Smokers Adjusted Mortality Risk Ratios for exposure to 24. 5 mg/m 3 fine particles Smokers – women – men 1. 16 1. 18 NEVER SMOKED – women – men 1. 22 1. 14

The Pope et al. study concludes that: • Risks for increased pollution exposure were The Pope et al. study concludes that: • Risks for increased pollution exposure were the same for smokers and non smokers • The association between pollution and mortality was not very sensitive to: occupation, education, body mass, alcohol, and temperature • occupational differences between men and women did not matter

There are other studies of this type • Typically they find the strongest relationship There are other studies of this type • Typically they find the strongest relationship with fine particles and sulfate aerosols • There is usually an association with all particles < 10 or 15 mm, but it is not as strong as with fine particles • Less of a relationship with aerosol acidity and almost none for O 3 CO, NOx

The latest interpretations do not find the strong relationship that was observed back in 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)

In A Particle Study in Bangkok, 1998 • health effects were associated with airborne In A Particle Study in Bangkok, 1998 • health effects were associated with airborne particles • They measured PM 10 • Particle concentrations in Bangkok tend to be higher than in other cities around the world

 • The results suggest that at current PM 10 concentrations in Bangkok, there • The results suggest that at current PM 10 concentrations in Bangkok, there are between 1, 000 and 2, 000 premature deaths each year • These deaths are attributable to shortterm exposures to outdoor airborne particulate matter • This represents about 5% to 10% of all recorded deaths in Bangkok

 • Hospital admissions for respiratory and cardiovascular illness are higher when PM 10 • Hospital admissions for respiratory and cardiovascular illness are higher when PM 10 concentrations are higher

 • For highly exposed adults, during the winter months, who do not spend • For highly exposed adults, during the winter months, who do not spend much time in airconditioned environments, • outdoor PM 10 was associated with twice the incidence of acute respiratory symptoms than was predicted when there is no pollution

 • For adults who spend substantial time in air-conditioned environments, the average outdoor • For adults who spend substantial time in air-conditioned environments, the average outdoor particulate matter during the winter months still increased their symptoms by about 20%

These types of studies • suggest a 1 -2% increase in the mortality rate These types of studies • suggest a 1 -2% increase in the mortality rate for every 10 ug/m 3 of fine particulate matter (Schwartz et al, 1996) • Contributed to the US EPA setting a PM 2. 5 ambient particle standard at 65 mg/m 3 for 24 hours, not to exceed the 3 rd highest value in 3 years; sampling ~1 time per week

Why is there a linear mortality rate response to particulate matter and what is Why is there a linear mortality rate response to particulate matter and what is the mechanism? ?

Samet et al. at UNC have recently exposed human airway epithelial cells to residual Samet et al. at UNC have recently exposed human airway epithelial cells to residual oil fly ash (ROFA) particles • cells secreted prostaglandins • Prostaglandins are a class of potent inflammatory mediators which play a role in inflammatory, immune and functional responses in the lung

Human volunteers had inert Fe 2 O 3 particles introduced into their lungs (Lay Human volunteers had inert Fe 2 O 3 particles introduced into their lungs (Lay et al, 1995) • Produced a subclinical inflammatory response in the first 24 -48 hours • Influx of macrophages and neutrophils onto the alveolar spaces as assessed by bronchoalveolar lavage • Protein releases suggests alveolar epithelial damage

 • Leakage of plasma protein and fluids in to alveolar space alters gas • Leakage of plasma protein and fluids in to alveolar space alters gas exchange of injured tissue • This is not a problem for a healthy person • people with compromised cardiac or pulmonary systems, however, may not be able to compensate or tolerate even mild exposures

Drop in U. S. air pollution linked to longer life-spans Americans are living longer Drop in U. S. air pollution linked to longer life-spans 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 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.

 • Chiang. Mai, Thailand • Do we see the same kinds of particle • Chiang. Mai, Thailand • Do we see the same kinds of particle health responses in northern Thai Populations? ?

 • Currently, there are only a few studies which relate PM 2. 5 • Currently, there are only a few studies which relate PM 2. 5 on a daily basis to mortality and morbidity

 • Chiang Mai was selected because it has high average fine particle concentrations • Chiang Mai was selected because it has high average fine particle concentrations • The concentrations change significantly with the seasons • We wanted to see if mortality would track the changes in particle concentrations

PM 10 concentrations change with the seasons PM 10 concentrations change with the seasons

 • The population of the city of Chiang Mai is ~170, 000 people • The population of the city of Chiang Mai is ~170, 000 people • If the average death rate is 750 people per 100, 000 people per year • This will give on average 3 or 4 deaths per day

IN 1998, The US EPA provided CMU with particle samplers • 8 saturation samplers IN 1998, The US EPA provided CMU with particle samplers • 8 saturation samplers with batteries; • more than 1000 Teflon filters; these can be used to obtain particle mass • Flow calibration gear • 7 - small samplers for personal monitoring

 • Saturation sampler for PM 2. 5 or PM 10 inlet 47 mm • Saturation sampler for PM 2. 5 or PM 10 inlet 47 mm filter holder pum p on/off digital timer rotameter lunch Battery 18 cm

 • It can be hung or strapped to a post pum p Battery • It can be hung or strapped to a post pum p Battery ~18 cm

So how do these samplers work? ? So how do these samplers work? ?

Sizing particles with impactors h. Impactors bring aerosols through a jet h. The particles Sizing particles with impactors h. Impactors bring aerosols through a jet h. The particles and air speed up as they go through the small orifice

Sizing particles with impactors h. Impactors bring aerosols through a jet disk • A Sizing particles with impactors h. Impactors bring aerosols through a jet disk • A disk or plate is place down stream of the jet

Sizing particles with impactors h. Impactors bring aerosols through a jet • The disk Sizing particles with impactors h. Impactors bring aerosols through a jet • The disk has grease or oil on the surface

Sizing particles with impactors • Depending on the speed through the jet, large particles Sizing particles with impactors • Depending on the speed through the jet, large particles will hit the disk, while small particles follow the air around the disk

Sizing particles with impactors Filter • A filter is placed under the disk to Sizing particles with impactors Filter • A filter is placed under the disk to collect particles that do not hit the disk

 • From this you can see the flow rate is very important. • • From this you can see the flow rate is very important. • The EPA samplers must flow at 5 liters/min • If we calibrate them in the lab at one temperature we must estimate the temperature, and pressure when we sample outside

 • From this you can see the flow rate is very important. • • From this you can see the flow rate is very important. • The EPA samplers must flow at 5 liters/min • When we calibrated them in the lab at one temperature, we had to estimate the temperature and pressure when we sampled outside

 • We changed filters and the battery once per day, 7 days / • We changed filters and the battery once per day, 7 days / week • Filters are weighed on a 5 or 6 place balance and stored in plastic petri dishes

Located samplers • residential area in the city- PM 2. 5 • 5 th Located samplers • residential area in the city- PM 2. 5 • 5 th roof top- urban sample not influenced by different sources - PM 2. 5 & PM 10 • high population density area (down town market? )- PM 2. 5 • relatively clean air- PM 2. 5

How do the samplers compare to each other when they are sampling in the How do the samplers compare to each other when they are sampling in the same location ? ?

We located 6 samplers on the 2 nd floor outside porch of Nui’s house We located 6 samplers on the 2 nd floor outside porch of Nui’s house and sampled for 24 hours on March 1, 1998

We located 6 samplers on 2 nd floor outside porch of Nui’s house and We located 6 samplers on 2 nd floor outside porch of Nui’s house and sampled for 24 hours on March 1, 1998

average 121 ug/m 3 2 x % std 8. 4% average 121 ug/m 3 2 x % std 8. 4%

Four different sampling locations were selected for monitoring PM 2. 5 • Down town Four different sampling locations were selected for monitoring PM 2. 5 • Down town area (Nui’s house) • Residential area (Dr. Usanee’s house) • General city exposure (outside 5 th floor of medical school) • Background (2 nd floor -Galae )

Chiang. Mai Chiang. Mai

How do the samplers at the different sampling locations compare ? ? How do the samplers at the different sampling locations compare ? ?

Chiang. Mai Chiang. Mai

When we sampled for more than one year winter Summer When we sampled for more than one year winter Summer

Chiang Mai Forest Fire Control Unit’s show the following number of fires Dec Jan Chiang Mai Forest Fire Control Unit’s show the following number of fires Dec Jan Feb Mar Apr May Jun-Nov 1998 0 63 647 1214 241 5 0 1999 10 361 1699 943 28 0

Winter Mixing height in meters (afternoon) Avg Wind speed Km/hr Temp (o. C) (avg Winter Mixing height in meters (afternoon) Avg Wind speed Km/hr Temp (o. C) (avg high/low) Summer 900 1400 3. 3 5. 2 30/17 35/25

PM 2. 5 level mg/m 3 His + of TA 100/plate Mutagenicity vs. PM PM 2. 5 level mg/m 3 His + of TA 100/plate Mutagenicity vs. PM 2. 5 Mar 98 Apr May Jun Jul Aug Sep 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.

Chiang. Mai Chiang. Mai

If the downtown site, for example, “experienced” a slightly higher exposure to diesel exhaust 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. 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.

Recommendations? i 2 stroke motor cycles account for half of the motor vehicles and Recommendations? i 2 stroke motor cycles account for half of the motor vehicles and can emit more than 10 times the amount that gasoline cars do. We need to go to 4 stroke engines i. Replace small diesel pick-up trucks gasoline engine pick-up trucksmaintenance off all vehicles i. Control open burning!!