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Administrative data

Endpoint:
health surveillance data
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Not reported
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Lung function of welders of zinc-coated mild steel: cross-sectional analysis and changes over five consecutive work shifts.
Author:
Marquart H, Smid T, Heederik D & Visschers M
Year:
1989
Bibliographic source:
Am. J. Ind. Med. 16(3): 289-96

Materials and methods

Study type:
biological exposure monitoring
Endpoint addressed:
acute toxicity: inhalation
Principles of method if other than guideline:
The lung function parameters in zinc-coated mild steel welders were analysed 5 d before and after the work shifts.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Zinc oxide

Method

Type of population:
occupational
Ethical approval:
not specified
Details on study design:
Subjects:
- Welders, indirectly exposed nonwelders (working in the vicinity of the welding line), and controls all worked in a coach work factory.
- All workers studied were Caucasian males.
- For number, age, height, weight, years worked in the exposure group, and smoking habits of the three groups, see ‘Table I’ in the reference. Smoking habits are presented as the amount of packs of cigarettes smoked per day multiplied by the number of years smoked (pack years) (Beck et al., 1981). One pack contains 25 cigarettes and one cigar or pipe of tobacco is equivalent to two cigarettes.
- The mean number of years worked as a welder (in the group of welders) was 8.5 year (s.d.: 6.9 year).
Exposure Measurements:
- During the work shift, dust was sampled personally using P-2500 sampling pumps (DuPont, Wilmington, Delaware USA) and PAS-6 (inlet diameter of 6 mm) sampling heads. Whatman grade 41 paper filters were used (Whatman, Maidstone, GB) In the PAS-6 samplers.
- The amount of dust sampled was measured gravimetrically. The concentration of zinc was assessed according to NIOSH guidelines [1979] by Atomic Absorption Spectrometry (AAS) after destruction of the filters in concentrated HN03. The detection limit of this method for the concentration of
zinc in the air was l.3 µg/m3
Lung-function Measurements:
- Spirometric lung function measurements of the subjects were conducted before and after the work shift on 5 consecutive days (Monday to Friday) using a Vicatest-5 dry "rolling-seal" spirometer (Mijnhardt B.V., The Netherlands)
- Lung function measurements and procedures concerning data selection were performed according to the standards of the European Community for Coal and Steel [Quanjer, 1983]
- Lung function parameters recorded were: Forced vital capacity (FVC), volume expired in the first second of an FVC test (FEV1), ratio FEV1/FVC, peak expiratory flow (PEF) rate, maximum expiratory flow rates at points of the FVC curve where 50 and 25 %, respectively of the vital capacity still has to be expired (MEF50 % and MEF25 %), and maximal mid-expiratory flow (MMEF) rate [NIOSH, 1979]. The changes of lung-function parameters over a work shift were calculated as the difference between the afternoon and the morning values.

Results and discussion

Results:
Exposure: The geometric mean of the personal dust exposure of the welders was significantly greater than that of both the exposed nonwelders and the controls (Student's t: p < .05). Geometric mean concentrations for welders were 0.91 mg/m3 (dust) and 34.0 µg/m3 (zinc).The highest measured concentrations of welding fume was 5.1 mg/m3 and 8.0 mg/m3; 8 h TWA. For details see ‘Table II’ in the reference.
Symptoms: there were no differences in reported symptoms between the three groups and there were no indications of the occurrence of metal fume fever in the factory.
Lung Function: No differences in Monday morning values of the lung-function parameters were significant at the 5% significance level among welders, exposed nonwelders, and controls, adjusted for height, age, and pack years smoked. For details see Table III in the reference.
The influence of ‘welding years’ was of borderline significance (p < .1; one-tailed F-test) for the FEV1 and for the ratio FEV1/FVC. An increasing number of welding years correlated with a decrease in values for these lung function parameters. For details of relation between lung function and ‘welding years’, see Table IV in the reference. Changes in lung function over a working wk: On average, all lung-function parameters showed higher values at the end of the work shift. Average changes within the exposure groups were also positive. Differences in mean changes between exposure groups were small compared to the intragroup variation and were considered not significant. There were no significant differences (p > .1) between the three groups in mean changes in lung function over the working wk (Friday afternoon value minus Monday morning value). For details see ‘Table V’ in the reference.

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
Under the conditions of the test, acute effects of exposure to welding fumes containing zinc were not demonstrated in exposed welder’s population
Executive summary:

A study was conducted to analyse lung function in welders of zinc coated mild steel.

 

Spirometric lung-function measurements were conducted 5 d before and after the work shift of welders of zinc-coated steel, nonwelders who were indirectly exposed to welding fumes, and controls. The parameters recorded were forced vital capacity (FVC), volume expired in the first second of an FVC test (FEV1), ratio FEV1/FVC, peak expiratory flow (PEF) rate, maximum expiratory flow rates at points of the FVC curve where 50 and 25%,respectively of the vital capacity still has to be expired (MEF50% and MEF25%), and maximal mid-expiratory flow (MMEF) rate. The exposure to dust and zinc of all participants was monitored personally using sampling pumps and PAS-6 samplers.

 

Cross-sectional analysis of Monday morning values showed no differences in lung function parameters between groups. However, the number of years the participants were engaged in welding was of borderline statistical significance and correlated negatively with values of FEV1 and FEV1/FVC. Changes in lung function over a work shift or a working wk were not related to the exposure level.

 

Under the conditions of the test, acute effects of exposure to welding fumes containing zinc were not demonstrated in exposed welder’s population.