Skip to main content
. Author manuscript; available in PMC: 2018 Feb 28.
Published in final edited form as: ACS Nano. 2017 Feb 8;11(2):1869–1883. doi: 10.1021/acsnano.6b07895

Table 5.

Dosimetry Calculations for GaAs in the workplace.a

1. GaAs exposure calculation premised on detecting As concentration of 2.7 mg/m3 in the workplace
2.7(mg As)m3×144.645(g GaAs/mol)74.92(g As/mol)=5.2(mg Ga As)/m3
2. Calculated weekly nanoparticles lung deposition (mass) in a worker exposed to 5.2 [mg/m] GaAs
    Assumptions:
    · Ventilation rate of a healthy human adult: 20 [L/min]
    · Deposition fraction: 30%
    · Weekly exposure period: 8 [h/day], 5 [d/week]
    Weekly lung deposition:
5.2mgm3×20Lmin·person×30%×60minhour×8hourday×5dayweek×m31000L=74.88mg
3. Weekly deposition level converted to mass/surface area in the human lung
    Assumptions:
    · Human alveolar surface area: 102 [m /person]
    Calculation:
74.88mgperson·week×person102m2=1000μgmg=734.12μg/m2
4. Comparable deposition level in a mouse receiving a one-time installation exposure
    Assumptions:
    · Alveolar epithelium surface area of a mouse: 0.05 [m /mouse];
    · Weight of a mouse: 25 [g]
    Calculation:
734.12μgm2week×0.05m2mouse×1mg1000μg×mouse25g×1000gkg=1.468mg/kg
a

Our animal experiments were based on a real-life As exposure measurement in a manufacturing facility, where airborne As levels were documented to be as high as 2.7 mg/m3.34 The chosen dose of 0.014 mmol/kg for each of the III-V materials equals to 1–4 mg/kg based on the molar weight in Table 3, which overlaps with the calculated mouse exposure dose of 1.468 [mg/kg].