ORIGINAL ARTICLE Roel Vermeulen Æ Bo A. G. Jo¨nsson Christian H. Lindh Æ Hans Kromhout Biological monitoring of carbon disulphide and phthalate exposure in the contemporary rubber industry Received: 10 October 2004 / Accepted: 1 June 2005 / Published online: 23 July 2005 Ó Springer-Verlag 2005 Abstract Objectives: We studied the range in urinary levels of 2-thiothiazolidine-4-carboxyl acid (TTCA), a metabolite of CS 2 and phthalic acid (PA), a common metabolite of phthalates, across factories and depart- ments in the contemporary rubber manufacturing industry. Methods: Spot urine samples from 101 rubber workers employed in nine different factories were col- lected on Sunday and during the workweek on Tuesday, Wednesday and Thursday at 4 pm. In total, 386 urine samples were successfully analyzed. Results: Levels of both biomarkers increased significantly by a factor 2 (paired t-test P-value <0.05) during the working week as compared to the Sunday biomarker levels with absolute increases of approximately 70 lg/l and 5 lmol/mol cre- atinine for PA and TTCA, respectively. Levels in both biomarkers did not differ markedly between working days. Increases seemed to be restricted to specific facto- ries and/or departments (e.g. molding and curing). Conclusions: The results of this study demonstrate that rubber workers in the contemporary rubber industry are exposed to phthalates and low levels of CS 2 (0.05 ppm) as measured by PA and TTCA, respectively. Exposures to both compounds are largely driven by specific cir- cumstances in factories. Therefore, when estimating exposures to phthalates and CS 2 detailed information should be collected on the type and amount of phthalate containing ester plasticizers, dithiocarbamates and thiu- rams used. Preferably, personal exposure data should be collected. In this case, biological monitoring seems a reasonable approach. However, in the case of PA attention should be given to individual background levels as this could lead to a substantial overestimation of the occupational contribution to total phthalate exposure. Keywords Rubber industry Æ Carbon disulphide Æ Phthalates Æ Biomonitoring Introduction Exposures in the rubber industry are multitudinous and have given rise to several occupational health concerns, among others, cancer, cardiovascular disease, pulmo- nary function abnormalities, hypertension, deterioration of intellectual and psychomotor function, nervous sys- tem dysfunction, and reproductive disorders (Roth 1999). Most of the epidemiological studies conducted so far have focused on the cancer risk in this industry. However, recently several contemporary cohort studies among rubber workers in the United Kingdom, Ger- many and Sweden have been initiated where in at least in one of these cohorts other health outcomes than cancer are being studied such as reproductive disorders, car- diovascular, and airways diseases (Mikoczy et al. 2004a, b). Historically, exposure to carbon disulphide (CS 2 ) has been linked to cardiovascular diseases within this industry (Danilenko and Kozintseva 1989; Delpech 1863; Roth 1999). Reproductive disorders have been observed in several studies among rubber workers and it has been hypothesized that this might be linked to exposure to rubber chemicals among, which CS 2 and/or phthalates (Duty et al. 2003; Figa-Talamanca 1984). Phthalates are widely used in the rubber industry as ester plasticizers. The most commonly used phthalate compounds are di- n-butyl phthalate (DBP) and di-iso- R. Vermeulen (&) Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, NIH, DHHS, 6120 Executive Boulevard, Rockville, MD, 20852 USA E-mail: vermeulr@mail.nih.gov Tel.: +1-301-4029850 Fax: +1-301-4021819 H. Kromhout Æ R. Vermeulen Division of Environmental and Occupational Health, Institute of Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands B. A. G. Jo¨nsson Æ C. H. Lindh Department Of Occupational and Environmental Medicine, University Hospital, Lund, Sweden Int Arch Occup Environ Health (2005) 78: 663–669 DOI 10.1007/s00420-005-0017-z