Western red cedar dust exposure and lung function: a dose-response relationship.

Abstract

The relationship between levels of cumulative red cedar dust exposure and decline in lung function was explored in an 11-yr follow-up study of 243 sawmill workers who participated in at least two occasions. We also studied 140 office workers in a similar manner as control subjects. Workers with asthma were excluded from the analysis. During the period of the study, 916 personal and 216 area samples of dust were collected from the sawmill. Cumulative wood dust exposure was calculated for each sawmill worker according to the duration and exposure in each job, based on the geometric mean of all dust measurements for that job. Average daily dust exposure was calculated by dividing the total cumulative exposure by the number of days of work. Workers were divided into low-, medium-, and high-exposure groups with mean daily level of exposure of < 0.2, 0.2 to 0.4, and > 0.4 mg/m3, respectively. Sawmill workers had significantly greater declines in FEV1 and FVC compared with office workers adjusted for age, smoking, and initial lung function. A dose-response relationship was observed between the level of exposure and the annual decline in FVC. We conclude that exposure to Western red cedar dust is associated with a greater decline in lung function which may lead to development of chronic airflow limitation.

Longitudinal lung function decline and wood dust exposure in the furniture industry

“…In other studies [3,10], relationships between wood dust exposure and decline in lung function have been revealed, especially among sawmill workers. Sawmill workers exposed to western red cedar were studied in an 11-yr follow-up study including 243 subjects [3]. Workers were divided into groups with mean average exposure between ,0.2 and .0.4 mg?m -3 .…”

“…Previous studies describing the relationship between chronic obstructive pulmonary disease (COPD) and exposure to wood dust have shown conflicting results: while a number of studies have shown an association between decreased lung function and wood dust exposure [2][3][4], others found no such association [5][6][7][8].…”

“…forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC) and current exposure [2,[4][5][6]. Some studies have used cumulative exposure indexes to evaluate differences in baseline lung function [3,7,8].…”

“…A few follow-up studies on sawmills processing western red cedar wood have suggested an accelerated decline in lung function in relation to wood dust exposure [3,10]. Western red cedar is the only type of wood that has been thoroughly studied and it has been revealed that a special compound (plicatic acid) is a causal agent for asthma among exposed workers.…”

Asthma incidence in wood-processing industries in Finland in a register-based population study

“…The proportion of all cases of occupational asthma due to wood dust has been reported to be some 6-11% (8). Asthma induced by western red cedar has been frequently documented for sawmill workers, with an apparent dose-response relationship (10)(11)(12)(13)(14). The studies proposing a relationship between exposure to other softwood species and asthma have used self-reported asthma (11) and clinically diagnosed asthma (15,16) as outcomes.…”