DUST EXPOSURE INDEXES AND LUND FUNCTION CHANGES IN LONGSHOREMEN AND DOCK WORKERS

A group of Dutch harbor workers involved in loading and unloading bulk products from sea vessels such as coal, cokes, and some other product s like alumina, borax, phosphate ore, and vermiculite was studied. Exp osures were characterized by personal and environmental monitoring. Th is information was subsequently used to estimate several dust exposure indices and to study relationships with lung function variables and r espiratory symptoms. Average respirable dust exposure levels ranged fr om 0.3-4.0 mg/m3. Workers involved in unloading products from sea vess els were exposed to the highest dust levels. Supervisors and workers w ith tasks in the dock had an intermediate to low exposure. Office work ers had the lowest exposure to respirable dust. Inhalable dust levels were considerably higher and average exposures ranged from 0.3-80 mg/m 3. The ranking of occupational titles by inhalable dust exposure was a lmost identical to the rank order of respirable dust levels. Workers w ith higher current and cumulative dust exposures tended to have a lowe r lung function, and only shortness of breath had a statistically sign ificant relationship with current and cumulative inhalable dust exposu re. In general, relationships between lung function and inhalable dust levels to be somewhat stronger in terms of statistical significance, because inhalable dust is an estimate of dust deposition in the upper airways and lung function is a measurable parameter of airway obstruct ion in that region. However, the differences with respirable dust were minimal, and variability in dust exposure levels was extremely large for this population. It was concluded that harbor workers involved in unloading ships containing coal and various kinds of ore can be expose d to high dust levels. Relationships between dust exposure and lung fu nction illustrate that these exposures are a respiratory hazard. Our f inding that inhalable dust levels have a somewhat stronger relationshi p with lung function level than respirable dust levels deserves furthe r attention. (C) 1994 Wiley-Liss, Inc.