Table 1.
Personal welding particulate concentrations (mg/m3) stratified by select ventilation and job characteristics
| All Observations | Shipyard A | Shipyard B | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | GM | (GSD) | n | GM | (GSD) | n | GM | (GSD) | ||
| All samples | 65 | 2.40 | (4.2) | 48 | 1.86 | (3.9) | 17 | 4.90 | (4.1) | |
| Descriptive Variables | ||||||||||
| Welding Method | ||||||||||
| SMAW | 5 | 0.75 | (4.5) | 5 | 0.75 | (4.5) | 0 | - | (-) | |
| FCAW (Dual Shield) | 49 | 3.18 | (3.6) | 32 | 2.53 | (3.2) | 17 | 4.90 | (4.1) | |
| FCAW (Inner Shield) | 5 | 3.67 | (4.9) | 5 | 3.67 | (4.9) | 0 | - | (-) | |
| Oxyacetylene | 6 | 0.44 | (2.9) | 6 | 0.44 | (2.9) | 0 | - | (-) | |
| Proximity of Welder's Head to Fume | ||||||||||
| In | 12 | 3.98 | (1.9) | 9 | 3.60 | (1.7) | 3 | 5.39 | (2.8) | |
| Near | 30 | 3.42 | (4.3) | 19 | 2.50 | (4.0) | 11 | 5.89 | (4.5) | |
| Away | 23 | 1.16 | (4.3) | 20 | 1.05 | (4.2) | 3 | 2.27 | (5.3) | |
| Space Volume | ||||||||||
| <28 m3 | 45 | 2.47 | (4.6) | 29 | 1.73 | (4.3) | 16 | 4.74 | (4.3) | |
| 28 m3 – 56 m3 | 18 | 2.39 | (3.7) | 17 | 2.22 | (3.7) | 1 | 8.28 | (-) | |
| >56 m3 | 2 | 1.23 | (2.3) | 2 | 1.23 | (2.3) | 0 | - | (-) | |
| Ventilation Characteristics | ||||||||||
| Ventilation Used | ||||||||||
| No | 19 | 2.31 | (4.4) | 19 | 2.31 | (4.4) | 0 | - | (-) | |
| Yes | 46 | 2.43 | (4.2) | 29 | 1.61 | (3.7) | 17 | 4.90 | (4.1) | |
| Air Changes per Minute | ||||||||||
| <1 | 34 | 2.35 | (4.4) | 29 | 2.05 | (4.1) | 5 | 5.26 | (6.6) | |
| 1–2 | 12 | 1.76 | (3.5) | 10 | 1.58 | (3.8) | 2 | 2.96 | (2.2) | |
| 2–3 | 2 | 2.39 | (1.2) | 2 | 2.39 | (1.2) | 0 | - | (-) | |
| >3 | 17 | 3.11 | (4.8) | 7 | 1.48 | (5.3) | 10 | 5.23 | (3.9) | |
| Mixing Used | ||||||||||
| No | 42 | 2.67 | (4.9) | 34 | 2.04 | (4.4) | 8 | 8.26 | (5.1) | |
| Yes | 23 | 1.97 | (3.1) | 14 | 1.48 | (3.0) | 9 | 3.08 | (3.0) | |
| Dead space | ||||||||||
| No | 31 | 2.37 | (3.8) | 21 | 1.84 | (3.8) | 10 | 4.02 | (3.5) | |
| Yes | 34 | 2.42 | (4.7) | 27 | 1.88 | (4.2) | 7 | 6.50 | (5.4) | |
| Crossdraft Used | ||||||||||
| No | 55 | 2.65 | (4.5) | 42 | 1.97 | (4.1) | 13 | 6.94 | (3.9) | |
| Yes | 10 | 1.38 | (2.6) | 6 | 1.25 | (2.7) | 4 | 1.58 | (2.7) | |
| Exhaust Proximity | ||||||||||
| Local | 2 | 1.08 | (47.1) | 2 | 0.61 | (7.2) | 0 | - | (-) | |
| Regional | 6 | 2.09 | (1.9) | 6 | 1.53 | (3.7) | 0 | - | (-) | |
| General | 19 | 1.57 | (3.5) | 18 | 1.55 | (3.7) | 1 | 2.04 | (-) | |
| Relative Exhaust Height | ||||||||||
| Below | 6 | 1.53 | (3.7) | 6 | 1.74 | (3.5) | 0 | - | (-) | |
| Even | 7 | 1.50 | (5.4) | 6 | 1.43 | (6.3) | 1 | 2.04 | (-) | |
| Above | 14 | 1.74 | (3.5) | 14 | 1.53 | (3.7) | 0 | - | (-) | |