OBJECTIVE

Metal working fluids (MWF) are used during the machining or treatment of metal components as aluminium. The study of adverse health effects of exposure to MWF is very important because the potentially exposed population is large. In this study, we evaluated 31 workers of three departments (Extrusion, Hot and Cold Rolling Mill) in a secondary aluminium plant.

METHODS

We combined exposure assessment to MWF and their biodegradation products (aldehydes, etc.) with biomonitoring 1-OH-pyrene in the urine and an evaluation of respiratory and dermatological complaints by using the Saint-George's respiratory questionnaire (SGRQ) and Dalgard's skin questionnaire.

RESULTS

We only detected MWF vapour levels of 4.1 and 5.5 mg/m3 at the Cold Rolling Mills. Only very small traces of solvents, organic acids and carbon-gasses were identified in all work environments. Several aldehydes were measured in low concentrations, e.g. formaldehyde at 0.03 mg/m3. 1-OH-pyrene levels were all around the detection limit of 0.2 microg/l. The scores of the Extrusion department were all within normal values as defined in the manual of the SGRQ. In contrast, the Hot and Cold Rolling Mill were scoring significantly above the score of a population without respiratory health problems. Moreover, the participants of the Hot and Cold Rolling Mill displayed a Dalgard's Skin score = 1.3 indicating that these individuals have an increased risk of developing skin diseases

CONCLUSION

We recommend measuring oil vapour, additives and contaminants in addition to oil mist only for assessing exposure to MWF. We also found indications that exposure to MWF vapours and emulsified MWF might lead to respiratory and skin problems, but a bigger epidemiological study in exposed workers will be necessary to make more definitive conclusions.