Neuroendocrine effects in printing workers exposed

The effect of exposure to toluene on plasma concentrations of testosterone, prolactin, luteinising (LH) and follicle stimulating (FSH) hormones was investigated in 47 rotogravure printers (time weighted average air toluene below 80 ppm; blood toluene concentration post-shift 0-19-7-99 umol/l) and compared with a reference group. Increasing exposure concentrations of toluene (concentrations <5 to >45 ppm) were significantly associated with decreasing plasma concentrations of LH (tau = -0-21, p = 0 003) and testosterone (tau = -0-25, p = 0-02). No correlation was found between cumulative exposure (ppm x years) and plasma hormone concentrations. The associations with exposure were present even when nine printers with heavy alcohol consumption were excluded. The study indicates an effect of low toluene exposure on the hypothalamus-pituitary axis, with a secondary decrease in testosterone secretion. Toluene has, like many other organic solvents, neurotoxic effects. Acute effects on the centralnervous system (CNS) are well known'2 and residual CNS damage is suspected after long term exposure to high concentrations of toluene.' Adverse effects of 2,5-hexanedione, which is the neurotoxic metabolite of the industrial solvents nhexane and methyl n-butyl ketone, have been found in the hypothalamus. It causes axonal degeneration in the mamillary body and other parts of the hypoDepartment of Occupational and Environmental Medicine B-G Svensson Department ofMedicine EM Erfurth Department ofOncology, University Hospital, S-221 85 Lund, Sweden H Olsson Department of Occupational Medicine, General Hospital, Malmo G Nise thalamic area, as well as in other central and peripheral nervous structures.4 Subacute exposure of rats to toluene, xylene, and ethylbenzene can produce changes in dopamine and noradrenaline concentrations and turnover in various parts of the hypothalamus.56 In this area catecholamine neurotransmission is important for the regulation of pituitary hormone secretion.`7-0 To investigate if the secretion of pituitary hormones was affected in men exposed to toluene, the plasma concentrations oftestosterone (P-Test), prolactin (PPRL), luteinising hormone (P-LH), and follicle stimulating hormone (P-FSH) were measured and compared with those of a reference group without exposure to toluene. Subjects and methods SUBJECTS Forty seven men from two rotogravure printing companies and exposed to toluene have been studied. One ofthe companies (A) is very modem and has low exposure. The other (B) has an older printing hall with higher toluene concentrations in the air. Most of the printers have been exposed to toluene in printing offices for many years. The mean duration of employment was 18 4 (range 4-33) years for the 28 men from companyA and 14 5 (range 3-39) years for the 19 men from company B. Twenty three workers from a metal industry and 23 craftsmen from hospital workshops were used as referents. None of these were exposed to organic solvents. The mean age for the exposed group was 44-4 (range 23-62) years, and for the referents 43-5 (range 20-61) years. A thorough clinical examination was carried out on each printer. Medical records from the local hospital, questionnaires, and personal interviews were used to obtain information on relevant life style and health state. Individual alcohol consumption was estimated carefully. Printers were regarded as "high alcohol consumers" when one or more of the following criteria were met: medical records indicating alcohol related disease, the presence of significant ethanol concentrations (> 0-5 g/l) in blood samples collected during working hours, or estimated weekly alcohol British Journal of Industrial Medicine 1992;49:402-408 group.bmj.com on June 19, 2017 Published by http://oem.bmj.com/ Downloaded from