Levels of 1-hydroxypyrene, symptoms and immunologic markers in vulcanization workers in the southern Sweden rubber industries.

OBJECTIVES The aim of this study was to determine urinary 1-hydroxypyrene (1-HP) levels in contemporary Swedish vulcanization workers and in controls. These levels were used as an index substance for vulcanization fumes, as well as a biomarker for polycyclic aromatic hydrocarbons (PAHs). The risk of symptoms and changed levels of immunologic markers were investigated in relation to the 1-HP levels. METHODS Included in the study were 163 exposed workers and 106 controls. Medical and occupational histories were obtained by structured interviews. Symptoms were recorded and immunologic markers analysed in blood by routine analysis methods. Levels of 1-HP were determined by liquid chromatography and fluorescence detection. RESULTS The highest levels of 1-HP were found among exposed workers using injection and compression vulcanization and lower levels were found among exposed workers vulcanizing with salt bath, hot air, microwaves or fluid-bed. Compared to controls, exposed workers had increased risks of eye symptoms, nosebleeds, burning and dry throat, hoarseness, severe dry cough, nausea and headache. Furthermore, exposed workers had elevated levels of neutrophils and total IgG (immunoglobulin subclass G). However, only for severe dry cough an evident exposure-response relationship with urinary 1-HP levels was found. CONCLUSIONS This work clearly shows increased levels of urinary 1-HP in Swedish vulcanization workers. Furthermore, it demonstrates an increased risk of several symptoms and elevated levels of some immunologic markers in these workers. However, no obvious exposure-response relationships were found.