9

Supplementary materials

Fig. S1. Layout of commodity ceramic factory.

Fig. S2. Layout of tile ceramic factory.

Fig. S3. Schematic representation of alveolar exposure model.

Fig. S4. Framework and computational algorithm used in this study.

Table S1. Published data used to derive the dose-response relationships for SiO2-polymorphonuclear leukocytes (PMN) and SiO2-lung hydroxyproline (HYP), respectively.

Table S2. Fitted coefficients of lognormal (LN) function for particle size distribution at commodity and tile ceramic factory.

Table S3. Long-term exposure risk estimates of inflammation and fibrosis in incremental durations 10–15, 15–30, and 30–45 yr at most effected working areas in two selected factories.

Fig. S1. Layout of commodity ceramic factory.

Molding (grouting) / Molding (extrusion) / Repairing / Primary shaping
Glazing / Primary shaping / Burning /


Fig. S2. Layout of tile ceramic factory.

Raw material / Soil-mixing / Granulation / Molding
Drying & Glazing / Glazing / Glaze-mixing / Burning
Quality control / Finished product / Shipment /


Fig. S3. Schematic representation of alveolar exposure model.

Fig. S4. Framework and computational algorithm used in this study.

Table S1

Published data used to derive the dose-response relationships for SiO2-polymorphonuclear leukocytes (PMN) and SiO2-lung hydroxyproline (HYP), respectively

Exposure
day / Silica lung burden (mg) / PMN / HYP
Rata / Humanc / (106-cell)b / (fold)d / (mg)a / (fold)e
Control / 0 / 0 / 0.89±0.27f / 0 / 0.67±0.07 / 0
5 / 0.56 / 168.07 / 5.83±2.22 / 5.55±2.49 / N.D.g / N.D.
10 / 0.82 / 246.99 / 6.01±1.26 / 5.75±1.42 / 1.38±0.32 / 1.06±0.48
20 / 1.47 / 442.77 / 7.30±0.93 / 7.20±1.04 / 0.85±0.22 / 0.27±0.33
41 / 3.18 / 957.53 / 11.08±2.19 / 11.45±2.46 / 0.88±0.17 / 0.31±0.26
79 / 5.49 / 1654.52 / 45.22±12.51 / 49.81±14.06 / 1.86±0.71 / 1.78±1.06
116 / 6.22 / 1873.80 / 143.16±44.79 / 159.85±50.33 / 3.17±0.71 / 3.73±1.06

a Adopted from Porter et al. (2001).

b Adopted from Porter et al. (2002).

c Extrapolated by adopted from Tran et al. (2001) where LBR is the silica lungs burden in rat, LWH is the human lungs weight of 1000 g and LWR is the rat lungs wright of 3.32 g.

d Normalized by where PMNmin is the PMN minimum value of 0.89 106-cell in control group.

e Normalized by where HYPmin is the HYP minimum value of 0.67 mg in control group.

f Mean ± sd.

g Not determined.

Table S2

Fitted coefficients of lognormal (LN) function for particle size distribution at commodity and tile ceramic factory

Working area / Fitted coefficienta / r2 / p
Commodity ceramic factory
Molding (grouting) / LN(9.10, 140.46, 10.76, 0.89) / 0.93 / ***
Molding (extrusion) / LN(23.65, 65.95, 8.69, 0.67) / 0.79 / ***
Repairing / LN(15.91, 77.94, 10.86, 0.83) / 0.78 / ***
Glazing / LN(6.76, 110.68, 7.13, 0.92) / 0.92 / ***
Burning / LN(9.62, 34.39, 5.64, 0.56) / 0.70 / ***
Tile ceramic factory
Soil mixing / LN(19.20, 2109.19, 9.46, 0.69) / 0.96 / ***
Glaze mixing / LN(12.76, 2600.00, 7.26, 0.55) / 0.93 / ***
Granulation / LN(1.50, 4639.00, 15.72, 1.11) / 0.91 / ***
Molding / LN(1.07, 4435.00, 13.92, 0.90) / 0.93 / ***
Drying & Glazing / LN(13.80, 1545.57, 12.48, 0.89) / 0.93 / ***
Burning (entrance) / LN(0.29, 470.92, 20.90, 1.12) / 0.94 / ***
Burning (middle) / LN(25.21, 831.88, 9.26, 0.66) / 0.96 / ***

*** p < 0.001.

a .


Table S3

Long-term exposure risk estimates of inflammation and fibrosis in incremental durations 10–15, 15–30, and 30–45 yr at most effected working areas in two selected factories

Incremental adverse effects elevation (fold)
10–15yr / 15–30yr / 30–45yr
Inflammation
Commodity factory
(Glazing) / 4.03×10-28
(1.15×10-28–1.40×10-27)a / 9.00×10-26
(1.03×10-26–7.08×10-25) / 1.96×10-23
(5.44×10-24–7.05×10-23)
Tile factory
(Granulation) / 2.54×10-4
(6.71×10-5–9.09×10-4) / 5.56×10-2
(6.67×10-3–4.92×10-1) / 1.04×10
(3.24–3.31×10)
Fibrosis
Commodity factory
(Glazing) / 8.44×10-30
(2.40×10-30–3.03×10-29) / 1.87×10-27
(2.16×10-28–1.59×10-26) / 4.17×10-25
(1.18×10-25–1.50×10-24)
Tile factory
(Granulation) / 5.17×10-6
(1.38×10-6–1.85×10-5) / 1.17×10-3
(1.38×10-4–9.95×10-3) / 2.19×10-1
(6.73×10-2–7.12×10-1)

a Median (2.5% – 97.5%).

References

Porter DW, Ramsey D, Hubbs AF, Battelli L, Ma J, Barger M, Landsittel D, Robinson VA, McLaurin J, Khan A, Jones W, Teass A, Castranova V (2001) Time course of pulmonary response of rats to inhalation of crystalline silica: histological results and biochemical indices of damage, lipidosis, and fibrosis. J Environ Pathol Toxicol Oncol 20: 1–14.

Porter DW, Ye J, Ma J, Barger M, Robinson VA, Ramsey D, McLaurin J, Khan A, Landsittel D, Teass A, Castranova V (2002) Time course of pulmonary response of rats to inhalation of crystalline silica: NF-kappa B activation, inflammation, cytokine production, and damage. Inhal Toxicol 14: 349–367.