Pragmatic Approach for Health Risk Assessment of Bauxite Tailing Waste Materials - Environmental Contamination: Health Risks and Ecological Restoration - page 98

TABLE 6.3
Cumulative.%.for.a.Speciic.Range.of.Bauxite.
Tailing.Particle.Size

EnToxID PM 2.5 PM 10 PM 250

EnTox.11 8.585074 17.55623 91.42739

EnTox.7 6.473802 14.36745 64.72323

EnTox.8 11.0446 23.42975 84.91839

EnTox.6 7.874993 16.24238 76.6757

EnTox.3 9.205302 19.92355 87.02744

EnTox.9 6.817268 15.11208 70.76206

EnTox.2 8.202545 18.01139 72.06393

EnTox.5 11.18186 22.96217 91.87329

EnTox.4 7.115728 15.22794 69.98528

EnTox.12 25.70403 42.02388 100

EnTox.13 26.29055 45.37628 100

EnTox.1 39.08025 64.09891 100

EnTox.10 23.58167 38.98474 93.75553

EnTox.14 7.599203 16.583025 96.700611

to.20%.in.the.BT1.and.BT3.dams,.whereas.BT3.had.39%-64%.of.PM 10 ..PM 2.5 .
was.about.50%.of.the.PM 10 .concentration.(Table.6.3)..It.is.noted.that.tailings.
collected. from. the. west. dam. (BT3). have. a. higher. volume. in. iner. particle.
sizes.of.both.PM 2.5 .and.PM 10 ..PM 2.5 .and.PM 10 .particles.are.considered.to.be.
relevant.for.inhalation.exposure,.whereas.PM250.particles.are.ingestion.rele-
vant.via.hand-to-mouth.activities.(Duggan.et.al..1985)..It.is.interesting.to.note.
that.the.size.distribution.proile.of.the.house.dust.is.similar.to.those.obtained.
for.the.tailings.in.the.west.dam.(Figure.6.2).though.PM 10 .and.PM 2.5 .are.lower.
in.percentages..This.is.expected,.as.lighter.particles.will.remain.airborne.and.
likely.travel.longer.distances.before.deposition.takes.place.

Mineralogical Composition and Elemental
Concentrations of Bauxite Tailings

Quantitative.analysis.was.performed.on.the.XRD.data,.using.the.commercial.
package.SIROQUANT.from.Sietronics.Pty.Ltd.(Belconnen,.ACT,.Australia)..
The.results.are.normalized.to.100%.and,.hence,.do.not.include.estimates.of.
unidentiied.or.amorphous.materials..The.XRD.results.are.summarized.in.
Table.6.4..XRD.shows.that.the.major.minerals.found.in.decreasing.concen-
trations.include.gibbsite,.kaolinite,.and.boehmite..The.south.dam.(BT2).has.
higher.quartz.content.averaging.6.3%,.with.the.highest.being.8.4%..The.west.
dam.(BT3).tailings.have.signiicantly.less.quartz.(crystalline.silica),.with.an.
average.of.0.7%,.slightly.less.gibbsite.but.more.boehmite..Although.it.is.dif-
icult.to.conirm.with.only.one.house.dust.sample,.its.mineral.composition.
is.similar.to.that.of.the.tailings.from.the.west.Dam..This.is.also.supported.