NATURAL AEROSOLIC M INERAL DUST S

NATURAL AEROSOLIC MNATURAL AEROSOLIC MINERAL DUSTINERAL DUSTSS

Edward DerbyshireEdward Derbyshire

Before and during a Mongolian dust storm Beijing, China, April 2003Before and during a Mongolian dust storm Beijing, China, April 2003

2007-2009

Tibet

Egypt

Mongolia

N. Pakistan

Karakoram

Palaeolakes

Debris fans

Glacier forelands

Yardangs

Yardangs

Some common dust sources

Impact – Case Studies 1 (Sahara)Impact – Case Studies 1 (Sahara)Non-industrial silicosis (‘Desert Lung’) was found in human lung Non-industrial silicosis (‘Desert Lung’) was found in human lung tissue > 50 yr ago…..autopsy showed high content of fine (<3tissue > 50 yr ago…..autopsy showed high content of fine (<3m) m) silica dustsilica dust

A radiographic study of 54 Bedouin people in the Negev Desert, showed the incidence of fibrosis to be age related, with progression more notable in women (13 out of 22) than in men (only 4 out of 32), perhaps related to greater exposure to dust in and around family tents.

[Bar-Ziv, J, Goldberg, GM. 1974. Simple siliceous pneumoconiosis in Negev Bedouins. Rch. Env. Health 29: 121]

Other findings from different parts of North Africa include radiological evidence of multiple micro-nodules scattered throughout the lungs, and considered to be consistent with silicosis.

Impact – Case Studies-1 (Ladakh)Impact – Case Studies-1 (Ladakh)

Work undertaken in two studies in Ladakh (Norboo et al. 1991; Saiyed et al. 1991) is of particular interest - a region without any mines or industries but in which (like China) dust storms are frequent.

Radiographic evidence taken from an equal number of men and women between the ages of 50 and 62 years in two villages (altitudes of 3200m and 3500m) showed important differences resulting from the higher dust concentrations at the lower of the two villages.

Several cases of progressive massive fibrosis were found in the lower village, with none in the upper one, suggesting that silicosis may cause appreciable morbidity at lower altitudes.

Norboo, T, Angchuk, PT, Yahya, M, Kamat, SR, Pooley, FD, Corrin, B, Kerr, IH, Bruce, N, Ball, KP. 1991. Silicosis in a Himalayan village population: role of environmental dust. Thorax 46: 341-343.

Saiyed, HN, Sharma, YK, Sadhu, SG, Norboo, T, Patel, PD, Patel, TS, Venkaiah, K, Kashyap, SK. 1991. Non-occupational pneumoconiosis at high altitude villages in central Ladakh. British Journal of Industrial Medicine 48: 825-829.

Mineral dust Mineral dust found on the found on the upper surfaces of upper surfaces of wooden roof wooden roof beams of beams of Ladakhi houses Ladakhi houses is all <15is all <15m, m, more than 25% more than 25% by weight being by weight being <1<1m; the silica m; the silica content is >content is >60%60%..

Mineral dust Mineral dust found on the found on the upper surfaces of upper surfaces of wooden roof wooden roof beams of beams of Ladakhi houses Ladakhi houses is all <15is all <15m, m, more than 25% more than 25% by weight being by weight being <1<1m; the silica m; the silica content is >content is >60%60%..

Impact – Case Studies-2 Impact – Case Studies-2

LadakhLadakh

Impact – Case Studies-3 (Ladakh)Impact – Case Studies-3 (Ladakh)Impact – Case Studies-3 (Ladakh)Impact – Case Studies-3 (Ladakh)

Close correlation between dust storm frequency and number of cases of pneumoconiosis –

village with low dust storm frequency: 2.0% of population

village with moderate frequency: 20.1% of population

village with high dust storm incidence: 45.3% of population

Close correlation between dust storm frequency and number of cases of pneumoconiosis –

village with low dust storm frequency: 2.0% of population

village with moderate frequency: 20.1% of population

village with high dust storm incidence: 45.3% of population

The larger of the two Ladakh studies (449 patients older than 50 years: 245 women, 204 men from 3 different villages: Saiyed et al 1991) showed typical cases of pneumoconiosis associated with progressive massive fibrosis and egg-shell calcification of the bronchial glands (indicative of high concentrations of free silica) in 101 cases (22.5% of the population sampled).

The large The large population population

subjected to subjected to frequent dust frequent dust

storms in storms in north China north China

probably probably includes includes

substantial substantial numbers of numbers of people with people with

non-non-occupational occupational

silicosissilicosis

Impact – Case Studies-Impact – Case Studies-1 1

North ChinaNorth China

Impact – Case Studies-Impact – Case Studies-1 1

North ChinaNorth China

Hexi Corridor dust pall (ca. 1km thick) over Lanzhou city (pop. 3.5 m), early summer

Hexi Corridor dust pall (ca. 1km thick) over Lanzhou city (pop. 3.5 m), early summer

Anxi County, Gansu Province, ChinaDATA on DUST*

Outdoor dust concentration (TSP) during storms: 42 mg/m3

(cf. recurrent outdoor range for this region 21 – 69 mg/m3)

Free silica content in dust: 34 - 61%Total suspended particulates, rural houses: ≤ 3.2 mg/m3

Anxi County, Gansu Province, ChinaDATA on DUST*

Outdoor dust concentration (TSP) during storms: 42 mg/m3

(cf. recurrent outdoor range for this region 21 – 69 mg/m3)

Free silica content in dust: 34 - 61%Total suspended particulates, rural houses: ≤ 3.2 mg/m3

Minghua, Hexi Corridor, ChinaDATA ON PNEUMOCONIOSIS+

Desert margin towns (based on a total of 395 X-radiographs)Incidence in the population in general: 7%Incidence in adults over 40 years of age: >40%Total number of people affected in N. China - unknown

Minghua, Hexi Corridor, ChinaDATA ON PNEUMOCONIOSIS+

Desert margin towns (based on a total of 395 X-radiographs)Incidence in the population in general: 7%Incidence in adults over 40 years of age: >40%Total number of people affected in N. China - unknown

Impact – Case Studies-2 (North China)Impact – Case Studies-2 (North China)

This demands improved understanding of

•Dust particle properties – size, shape, mineralogy/geochemistry – laboratory data

•Dust sources & pathways – observational data

as a basis for assessment of particle surface reactivity and toxicology

Interest in refining data on these subjects has increased steadily in the past decade, especially for Mid, Central and East Asia, and the peri-Saharan regions.

This demands improved understanding of

•Dust particle properties – size, shape, mineralogy/geochemistry – laboratory data

•Dust sources & pathways – observational data

as a basis for assessment of particle surface reactivity and toxicology

Interest in refining data on these subjects has increased steadily in the past decade, especially for Mid, Central and East Asia, and the peri-Saharan regions.

Particle size

1. Canary Islands

Typically, almost 40% of the dust of

the calima of March 2004 in Gran

Canaria was finer than 10 microns2. Dead Sea, Israel

Particle-size distribution of (salt-free) atmospheric

deposition over the Dead Sea (Malvern model Mastersizer

Laser):

(a) collected on 4th November, 1998;

(b) 23rd March, 1998 and

(c) 20th July, 1998.

[Singer et al. 2003]

Si - abundant to dominant Si - abundant to dominant element in Saharan dust element in Saharan dust <10<10µmµm

Si - abundant to dominant Si - abundant to dominant element in Saharan dust element in Saharan dust <10<10µmµm

Quartz amounts in major Quartz amounts in major dust storms are very dust storms are very similar (similar (60.95% in North 60.95% in North AfricaAfrica), closely matching ), closely matching the global value (58.98%) the global value (58.98%)

CompositionComposition

CompositionCompositionCompositionComposition

Entrainment of material < 2 µm

Silt-size aggregates of Silt-size aggregates of clay grade particles. Clay clay grade particles. Clay grades are detached and grades are detached and transported as transported as aggregates, not as aggregates, not as single grains. single grains.

Silt-size aggregates of Silt-size aggregates of clay grade particles. Clay clay grade particles. Clay grades are detached and grades are detached and transported as transported as aggregates, not as aggregates, not as single grains. single grains.

Ankerite Fe0.54 2.39 %

Calcite 17.06 %Hematite 0.608 %

Kaolinite C1, an, BISH 30.9 %

Microcline, intermediate1 6.02 %

Muscovite_2M1 13.63 %Plagioclase Albite 9.05 %

Quartz 20.36 %

Quantitative MineralogyQuantitative MineralogyQuantitative MineralogyQuantitative Mineralogy

Saharan dust pall, Lanzarote, June 2002Saharan dust pall, Lanzarote, June 2002

Courtesy of Johann Engelbrecht

Rapid, automated analysis using the Bruker D8 XRD system Rapid, automated analysis using the Bruker D8 XRD system

[Courtesy of Johann Engelbrecht]

OBSERVATIONAL DATA

Ground-based.Ground-based.

Global synoptic atmosphere circulation data and derived models. Global synoptic atmosphere circulation data and derived models.

Orbital data. Orbital data.

LIDAR (Light Detection and Ranging)LIDAR (Light Detection and Ranging)

The long-term global dust The long-term global dust storm frequency shows a storm frequency shows a distribution of major sources distribution of major sources closely similar to other data closely similar to other data sources - sources - sources occur in all sources occur in all continents except Europe and continents except Europe and Antarctica.Antarctica.

Mean number of ‘dust Mean number of ‘dust days’ (defined as days’ (defined as reduction in visibility by reduction in visibility by dust to < 1km)dust to < 1km)80 in south-west Asia80 in south-west Asia

>60 in Turkmenistan >60 in Turkmenistan and the Karakum and the Karakum

>45 in Kazakhstan >45 in Kazakhstan

>30 in the Tarim Basin >30 in the Tarim Basin (Taklamakan), the Hexi (Taklamakan), the Hexi Corridor and the Loess Corridor and the Loess Plateau (China) Plateau (China)

~30 in parts of North ~30 in parts of North Africa Africa

~20 in the NW Indian ~20 in the NW Indian sub-continent sub-continent

>15 in central Australia.>15 in central Australia.

[after Middleton et al. 1986]

after Prospero

2002

[After Prospero 2002][After Prospero 2002]

The altitude The altitude effecteffect

Canary Is.Canary Is.

Example of a Example of a “winter pattern” “winter pattern” (Sahelian) dust (Sahelian) dust outbreak (26 outbreak (26 February–15 February–15 March 2000). March 2000). ambient PM10 ambient PM10 levels (TSP). levels (TSP).

SeaWIFS image SeaWIFS image &TOMS aerosol &TOMS aerosol

index mapindex map

Dominant meteorological

scenario during the winter Sahelian dust outbreaks; 925 and 850 hPa

pressure levels, 26 Feb. 2000, 1200 h.

[Viana et al. 2002]

Backward trajectory at mid-point of calima of 3 – 8 March 2004 - track across NW

Sahara suggestive of summer half-

year pattern.

However, estimated

thickness of dust pall on Gran Canaria and

Tenerife only 1 to 1.5 km (i.e. low

altitude) is consistent with winter half-year mode, however.

[courtesy of Denis D. [courtesy of Denis D. Rousseau]Rousseau]

Backward trajectory at mid-point of calima of 3 – 8 March 2004 - track across NW

Sahara suggestive of summer half-

year pattern.

However, estimated

thickness of dust pall on Gran Canaria and

Tenerife only 1 to 1.5 km (i.e. low

altitude) is consistent with winter half-year mode, however.

[courtesy of Denis D. [courtesy of Denis D. Rousseau]Rousseau]

Two Chinese dust sources of global importance –

Mongolia(pink flow-path) and Taklamakan Basin (yellow flow-path)

Two Chinese dust sources of global importance –

Mongolia(pink flow-path) and Taklamakan Basin (yellow flow-path)

Dust carried by both airstreams has been recognised in Greenland ice cores….

…..and in the snows of the French Alps (>20,000km pathway)

Dust concentration Description[mg m3]

0.083 Normal background0.356 ‘Detachment mode’1.206 Extensive dust pall3.955 Ordinary dust storm

(Chinese Meteorological Bureau)

Sr, Nd and Pb -isotope ratios

(isotope composition varies with the PSD in some dust samples, so PSD measurement is necessary)

[after Grousset & Biscaye 2005]

Source-specific properties stable during long-range Source-specific properties stable during long-range windborne transport windborne transport

Source-specific properties stable during long-range Source-specific properties stable during long-range windborne transport windborne transport

clay mineralogy

major or minor elemental ratios

rare earth element (REE) abundances

On 26–27 March 2003, 50% of the dust particles in

Japan came from North Africa, about 30% from the

Middle East, and only about 10% from China in

the boundary layer.

This simulated result is consistent with polarization

lidar and sky radiometer observations.

[Tanaka et al 2005]

On 26–27 March 2003, 50% of the dust particles in

Japan came from North Africa, about 30% from the

Middle East, and only about 10% from China in

the boundary layer.

This simulated result is consistent with polarization

lidar and sky radiometer observations.

[Tanaka et al 2005]

EVENT-BASED MODELSEVENT-BASED MODELSEVENT-BASED MODELSEVENT-BASED MODELS

N Minimum Max Median Dep. typical

Mn (ng/m3) 63 2.12 1096.02 50.14 141.69

Fe (μg/m3) 101 0.9 57.00 1.98 5.85

Co (ng/m3) 101 0.16 23.00 1.13 2.46

Pb (ng/m3) 101 1.51 44.78 9.90 7.83

Cu (ng/m3) 101 1.76 63.93 11.64 12.90

Cd (ng/m3) 101 0.01 2.75 0.24 0.40

Mg (μ/m3) 100 0.03 429.39 17.56 59.94

Al (μ/m3) 100 0.30 148.60 4.40 15.06

Ca (μ/m3) 78 0.23 786.10 23.82 119.56

Na (μ/m3) 100 0.27 802.48 70.84 103.81

Cr (ng/m3) [but species critical] 41 1.20 154.38 18.72 29.62

Zn (μ/m3) 79 0.01 11.92 0.50 1.36

Ni (ng/m3) 38 0.32 31.72 3.38 5.71

Ti (μ/m3) 38 0.05 0.46 0.15 0.09

CancerCancer Emphysema

Gran Canarian Dust - Trace Aerosol Composition (at Taliarte site – near sea level)

Links between selected elements in Saharan dust and some known lung function conditions and diseases

Gran Canarian Dust - Trace Aerosol Composition (at Taliarte site – near sea level)

Links between selected elements in Saharan dust and some known lung function conditions and diseases

Cancer suspected

AsthmaCancer & asthmaOther agents – no data for Gran Canaria: As (cancer) and V

(asthma)Other agents – no data for Gran Canaria: As (cancer) and V (asthma)

Diatoms typical of those deflated from desiccated Saharan-Sahelian dry lake basins, e.g. Aulacoseira granulata

Diatoms typical of those deflated from desiccated Saharan-Sahelian dry lake basins, e.g. Aulacoseira granulata

Biogenic Silica

- common in atmospheric dusts

Biogenic Silica

- common in atmospheric dusts

15 µm

PhytolithPhytolith

Testate amoeba

Organic tracers - phytoliths, lacustrine diatoms, pollen, etc. –indicate a continental origin and possibly a specificClimate area –but may not indicate precise source of dust pall