[Haematological data relating to phenol excretion in urine with chronic benzene exposure. I. Epidemiological studies of adults (author's transl)].

The phenol excretion in 24-h-urine has proved in epidemiological studies of normal population as a parameter, which can be measured very well and is sufficient exact as a parameter for a benzene burden. For an exact assessment of healthy impairment of the investigated collectives only the height of the phenol level is not sufficient. Therefore in the presented study the parameters little blood picture, differential blood picture, thrombocytes and reticulocytes were measured relating to the phenol excretion. 60-65 years old male and female adults from six districts of a large city in the strong industrialized North-West of the Ruhr-Area were investigated. The districts were differently exposed (i.e. 55 t/a benzene) to emissions. Adults at the same age from a little residential town (approx. 16 km apart) were investigated as a comparative collective. In the nearer environs there are no industrial emittents existing. - The different exposure situation is reflected well in the mean values of the collective exposure parameters. In the residential town you can find a lower phenol excretion, statistically guarded, corresponding with higher values of thrombocytes and leukocytes. Corresponding with phenol levels in urine the exposed districts presents the more adverse blood parameters. - The reticulocytes and MCHC values, like the MCV and MCH values show a similar trend corresponding with phenol values, statistically guarded. The other parameters, especially the differential blood picture, show no or little relation to the phenol values and give no indication of the exposure situation. - The combination of lower thrombocytes and leucocytes values, the trend to lower erythrocytes values (only females) and to higher MCH values in the industrial districts indicate a pancytopenic influence on the bone marrow as a characteristic for a benzene burden. - The higher reticulocytes count and its influence on the MCHC and MCV values suggest a reactive activity of the bone marrow. The absence of left displacement in the white blood picture let us suppose a compensated reaction. An acute healthy impairment of the population is not provable; therefore benzene is a certain carcinogen, it is not possible to estimate the potential hazard of the population for a longer period. For better registration of the real endangering of the population further more investigations are proposed.