[Effect of directed infrared radiation on the skin and eye of rabbits after acute and chronic exposure].

The establish a threshold dose, an acute experiment was carried out by 30 min. radiation of the rabbit's shaved head with all ranges of infrared, 200 W/m2, 350 W/m2 and 500 W/m2 intensities. Irradiation was prolonged up to 2 hrs.

[Effects of detergents on lead absorption].

The effects of orally administeredated detergents (rokafenol and siarczanol) on the absorption of lead from rabbits alimentary duct were reviewed. The absorption of lead was evaluated by the activity of delta--aminolevulinic acid dehydratase of erythrocytes, delta--aminolevulinic acid level in urine and the level of lead in the blood and liver. The detergents were found to increase the absorption of lead.

[Criteria used in the evaluation of the usefulness of surface-active agents in the fight against dustiness in coal mines].

The paper specifies the technical and biological criteria for evaluating the surface-active compounds used in preventing the dustiness, mainly in mines. In addition, effects of these compounds on the organism were discussed.

[Effect of metal dust on the respiratory system. II. Clinical examinations].

Studies were carried out in 4 groups of workers occupationally exposed to cadmium, tungsten, manganese and lead. All those groups were homogeneous, composed exclusively of men aged 35--45, of similar height, body weight, and duration of employment above 10 years. Following the same criteria, a group of forestry workers, unexposed to dust, was randomly selected.

[Effect of metal dust on the respiratory system. I. Experimental studies].

The Wistar rats were intratracheally administered 50 mg of PbO dust, the same amounts of metalliferous dust from one of lead--and zinc works and of ferrotungsten dust, and 10--15 mg of cadmium dust (greater doses of cadmium dust resulted in animals' death). After 6 months, and in the case of cadmium dust after 9--12 months, the animals were dissected and their lungs were morphologically examined and hydroxyproline level was determined. In all groups hydroxyproline was found to be increased but fibrosis was different, especially in the group exposed to cadmium dust.