[Practice of recognizing benzene-caused occupational diseases in 2006]

Benzene-caused hematologic diseases can be recognized as occupational diseases (ODs) if they fulfill the legal requirements specified under No. 1303 of the appendix of the German ordinance on ODs. The aim of this study is to analyze the most important criteria that determined whether these diseases were recognized or rejected as ODs according to No. 1303 in 2006.

In 2006, 70 suspected cases of OD No. 1303 reported in North Rhine-Westphalia were examined in terms of diagnosis, notifiers, cumulative benzene exposures, professions, coexposures, delays in notification, latency periods, interim periods, and recognition criteria.

70 benign and malignant diseases of myeloid and lymphoid origin were reported as suspected ODs, among them 41 B-cell non-Hodgkin's lymphomas (B-cell NHL). Latency periods ranged between 14 and 57 years (median 37; mean 36.3+/-11.4; n=45), estimated cumulative benzene exposures varied from 0 to 144 ppm-years (median 12; mean 11.4+/-22.8; n=59). Four of 70 suspected cases were recognized as OD No. 1303. In 37 cases (52.9%), the nature of the disease was assessed as being nontypical of OD No. 1303, in 50 cases (71.4%), no sufficient benzene exposure could be found. Mature-cell NHL and Hodgkin's lymphoma were not recognized as OD. Cumulative benzene exposures

When diagnosing hematologic diseases, physicians should ask the patients about their occupational history and, in particular, consider benzene exposures dating back several decades. To improve the state of knowledge of OD No. 1303, it is important that diseases are consistently classified according to WHO criteria and any kind of myeloid and lymphoid disease, including NHL, is reported.