Pragmatic Approach for Health Risk Assessment of Bauxite Tailing Waste Materials - Environmental Contamination: Health Risks and Ecological Restoration - page 97

Metals/metalloids.were.measured.in.the.0.45.μm.iltrate.of.the.extracts..The.
amount.found.in.each.extract.was.then.compared.to.the.actual.amount.(cal-
culated.from.the.initial.total.elemental.concentration).put.in.the.GI.digestion.
tube.to.derive.the.BAC.value.(%).of.each.metal/metalloid.targeted..The.over-
all.BAC.is.the.average.of.12.measurements.representing.the.various.physi-
ological.states.of.a.human.being.during.his.or.her.active.period.of.a.day.

ResultsandDiscussion
Particle Distribution Profile

Particle. size. distribution. proiles. of. the. samples. are. shown. in. Figure. 6.2..
Nanoparticles. were. not. observed. in. any. of. the. samples.. Most. of. the. par-
ticles.were.in.the.range.of.<250.μm..Particle.size.of.<250.μm.is.the.fraction.of.
soil/dust.likely.to.stick.to.human.hands,.resulting.in.exposure.via.hand-to-
mouth.activities.(Duggan.et.al..1985).
Accumulative. PM 10 . ranged. from. 14%. to. 64%. of. the. composition. of. dust.
particles.up.to.PM250.in.three.bauxite.tailings.dams..PM 10 .ranged.from.14%.

Particle size distribution Particle size distribution

4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0.1

6
5
4
3
2
1
0
0.1

10 100 1000

1

1 10 100 1000

(C)

(A) Particle size (µm)

Particle size (µm)

Particle size distribution Particle size distribution

6
5
4
3
2
1
0
0.1

8
7
6
5
4
3
2
1
0
0.01

1 10 100 1000 3000 1 10 100 1000

0.1

(D) (B) Particle size (µm) Particle size (µm)

FIGURE 6.2
Representative. particle. distribution. proiles. measured. in. samples. collected. from. the. bauxite.
tailings. dams. RT1,. RT2,. RT3,. and. the. composite. house. dust.. (A).=.RT1. (north. dam,. southwest.
location),.EnTox.6;.(B).=.RT2.(south.dam,.northwest.location),.EnTox.2;.(C).=.RT3.(west.dam,.north-
west.location),.EnTox.13;.and.(D).=.composite.house.dust,.EnTox14,.in.close.proximity.to.RT3.