Respiratory Symptoms and Occupational Exposures in New Zealand Plywood Mill Workers

Abstract

Objectives: To study work exposure and respiratory symptoms in New Zealand plywood mill workers.Methods: Personal inhalable dust (n = 57), bacterial endotoxin (n = 20), abietic acid (n = 20), terpene (n = 20) and formaldehyde (n = 22) measurements were taken and a respiratory health questionnaire was administered to 112 plywood mill workers.Results: Twenty-six percent of the dust exposures exceeded 1 mg/m 3 , however, none of the samples exceeded the legal limit of 5 mg/m 3 [geometric mean (GM) = 0.7 mg/m 3 , geometric standard deviation (GSD) = 1.9]. Workers in the composer area (where broken sheets are joined together) were significantly (P < 0.01) more highly exposed. Endotoxin levels were low to moderate (GM = 23.0 EU/m 3 , GSD = 2.8). Abietic acid levels ranged from 0.3 to 2.4 µg/m 3 (GM = 0.7 µg/m 3 , GSD = 1.8) and were significantly (P < 0.05) higher for workers in the composer area of the process. Geometric mean levels of α-pinene, β-pinene and ∆ 3 -carene were 1.0 (GSD = 2.7), 1.5 (GSD = 2.8) and 0.1 (GSD = 1.4), respectively, and α-pinene and β-pinene levels were significantly (P < 0.001) higher for workers in the 'green end' of the process, up to and including the veneer dryers. Conclusions: Plywood mill workers are exposed to inhalable dust, bacterial endotoxin, abietic acid, terpenes and formaldehyde, and they appear to have an increased risk of developing work-related respiratory symptoms. These symptoms may be due to formaldehyde exposure, although a potential causal role for other exposures cannot be excluded.

Respiratory health effects of exposure to low levels of airborne endotoxin – a systematic review

“… GM 39.4 EU/m 3 , range 4–7182 No significant differences in prevalence of respiratory symptoms among exposed workers when compared to controls. Fransman et al (2003) [ 55 ] 112 plywood mill workers. 415 controls of the general population.…”

“…The symptoms that were found to be significantly more prevalent among exposed subjects were cough [ 41 , 49 , 51 – 54 ], wheeze [ 49 , 55 , 56 ], shortness of breath [ 41 , 49 , 52 , 55 ], (work-related) chest tightness [ 34 , 49 , 54 , 56 ], chronic bronchitis [ 53 ] and (work-related) asthmatic symptoms [ 41 , 56 , 57 ]. Fransman et al found that plywood workers exposed to 23 EU/m 3 endotoxin had significantly more attacks of shortness of breath with wheezing than unexposed controls and that workers employed > 6.5 years had significantly more asthma, shortness of breath and wheezing when compared to members of the general population [ 55 ]. Smit et al also showed a significant positive association between length of employment and lower respiratory tract (LRT) symptoms [ 41 ].…”

“…Smit et al also showed a significant positive association between length of employment and lower respiratory tract (LRT) symptoms [ 41 ]. Two studies found that respiratory symptoms lessened during holidays/days off; 53–83% of respiratory symptoms lessened during holidays in one study [ 55 ], another study found a PR of 2.84 (95%CI 1.56–5.18) for decline in symptoms of wheeze during holidays [ 56 ]. Shiryaeva et al found that the highest frequency of symptoms was present on Mondays and that symptoms decreased gradually over the week, wheeze and chest tightness decreased significantly [ 58 ].…”

Bioaerosol exposure by farm type in Korea

“…Although the endotoxin concentrations on open field farms, greenhouse farms, and cowsheds were lower than those at hog farms and poultry houses, even those low concentrations might adversely affect health. In a study in New Zealand, plywood workers exposed to 23 EU/m 3 of endotoxins had significantly more attacks of shortness of breath with wheezing than unexposed controls [26]. In addition, another study showed that the mean FEV1 on spirometry decreased among potato processing workers exposed to 56 EU/m 3 of endotoxins [27], and a further study found a mean decrease in the FEV1 of textile yarn workers exposed to endotoxin levels of 0.64 EU/m 3 [28].…”

The impact of wood dust on pulmonary function and blood immunoglobulin E, erythrocyte sedimentation rate, and C‐ reactive protein: A cross‐sectional study among sawmill workers in Tangail, Bangladesh

“… 20 The abatement of lung function can worsen due to wood dust containing biological organisms, such as endotoxin, Gram‐negative bacteria, allergenic fungi, and mold. 21 , 22 Also, biological organisms may lead to hypersensitivity reactions that subsequently lead to asthma. 8 …”