To date, oil mist exposures to workers in several differ- ent industries have been assessed。 These include steel millers [14], cable manufacturing workers [15], car-making workers [16], ship engine maintenance workers [17,18], and tunnel con- struction workers [19] ( Table 1)。 Among them the car-making workers were found with the highest exposure level (2。6 mg/m3)。 But to the best of our knowledge, the concentrations of oil mists exposed to fastener manufacturing industry workers has never been assessed。

The objectives of this study were set out first to assess the inhalable fraction of oil mists exposed to workers in fastener manufacturing industries。 Considering several health effects are associated with the exposures of oil mists in different regions of

Table 1

The average oil mist exposure levels for workers in different industries Exposure group Exposure concentration (mg/m3)Reference

Steel millers 0。27–1。6 [14]

the respiratory tract, particle size segregating samplings were conducted in each involved workplace in order to estimate workers’ oil mist exposures to the head, tracheobronchial, and alveolar regions simultaneously。 The results obtained from this study will provide useful information for fastener manufactur- ing industries to seek suitable control measurements for reducing workers’ exposures in the future。

2。Material and methods

2。1。Sampling strategies

2。1。1。Personal inhalable aerosol sampling

Seven manufacturing processes, including the wire drawing, forming, threading, cleaning, heat treatment, surface treatment, and packaging and shipping were involved in for manufacturing fasteners。 In order to have a smooth production, all these pro- cesses are located in one building in all fastener manufacturing industries in Taiwan。 For this, only one factory was selected in this study。 For the selected factory, all workers involved in the use of MWFs were selected from three manufacturing processes (including 17, 11 and 6 workers from the forming, threading, and heat treatment processes, respectively) for conducting personal samplings by using an IOM personal inhalable aerosol sampler (SKC Inc。, Eighty-four, PA, USA)。 The sampling flow rate was specified at 2 L/min and the sampling time was designated to 7–8 h for each collected sample。

2。1。2。Particle size segregating samplings

Particle size segregating samplings were conducted on the workplace atmospheres of the three selected industrial processes by using a modified Marple 8-stage cascade impactor (m- Marple)。 The sampler consists an inlet foam stage (Ø = 30 mm, depth = 12。5 mm, 10 pores per inch, with a 50% cut-off aerody- namic diameter (d50%) of 27 µm), eight impaction stages (with d50%s of 21。3, 14。8, 9。8, 6。0, 3。5, 1。55, 0。96, and 0。52 µm, respec-

tively), and a back-up filter。 A 34 mm PVC filter with 5。0 µm

pore size was used as the collection medium。 The inlet of the m- Marple has been proven with aerosol aspiration efficiencies of unity for particles with aerodynamic diameter less than 56 µm under calm air situation (environmental wind speed <0。5 m/s) [20]。 For each industrial process, four particle size-segregating samples were collected by uniformly placing four m-Marples in the involved workplace。 The wind velocities of the three selected industrial processes were measured and found to be consistently less than 0。3 m/s suggesting that the resultant parti-

Cable manufacturing workers

(impregnation, sheathing, and installation of paper insulated)

2。25 [15]

cle size distributions could be representative to those containing in the workplace atmospheres。