Respiratory functional status of Chernobyl clean-up workers: results of 7-year observation

Abstract

We assessed results of 7-year monitoring of lung function in 33 Chernobyl accident liquidators using spirography, bodyplethysmography, lung diffusion capacity test, BAL cytology, and lung tissue biopsy. Among them 20 patients were treated since 1993, 13 patients were not treated. All the treated patients initially showed normal lung function values, but now 9 of them have kept normal flow rate values (the 1nd group). Ten others developed bronchial obstruction (the 2st group). The untreated patients (the 3rd group) had airflow limitation starting the observation. The 2nd group patients reduced their FVC from 4.67±0.15 in 1993 to 3.52±0.16 L in 2000 and FEVt from 3.69±0.15 to 2.72±0.17 L (p<0.02). The average FEVt annual decline was 71.16±36.58 Ml for the 1st group and 127.8±44.51 mL for the 2nd group. Lung volume parameters were normal in all the groups and did not change significantly. A number of alveolar macrophages containing Chernobyl dust particles decreased reliably in the 1st group: from n 24.65±5.18% in 1993 to 6.0±2.42% in 2000 (p<0.05), but not reliably in the 2nd group (from 17.83±4.24% in 1993 to 3.33±2.16% in 2000). The 3rd group patients has greatly less amount of such macrophages in spite of the absence of the therapy. Focal pulmonary fibrosis was revealed in 5 patients of the 1st group (55.6%), 4 patients of the 2nd group (36.4%) and 2 patients of the 3rd group (15.4%, p<0.025) without any X-ray features of lung fibrosis.
Thus, 73% of persons had exposed to inhaled radionuclides developed lung function disorders which greatly and progressively impair. A number of laden alveolar macrophages reduces over time without any eliminating treatment. Initial elimination rate of radionuclides provides a severity of delayed bronchial obstruction. Bronchial obstruction occurs less frequently and severe under the eliminating therapy. Focal pulmonary fibrosis at the initial stage does not influence the respiratory functional status probably due to its small size.