Cadmium exposure pathways in the Czech urban population.

The article describes the exposure pathways of cadmium in the Czech urban population. The data on Cd concentrations originated from the Environmental Health Monitoring System, which has been realized in 30 cities since 1994. The data on cadmium content in particular exposure pathways - diet, drinking water, ambient air and soil -were processed for the period 1994-2003. The estimate of the daily dietary intake for an average adult population amounted to 11-19 microg/d, i.e. 0.17-0.30 microg/kg bw/d, which represents 17%-30% of the PTWI (provisional tolerable weekly intake). The contribution from drinking water to the oral exposure is low; on average 0.5 microg/d. Potential exposure to airborne Cd was estimated at about 0.02 microg/d. The additional Cd intake from urban soil ingestion probable in small children was found to be insignificant based on Cd concentrations in the soil of kindergarten playgrounds. Biomonitoring outputs characterize the recent and life-long cadmium burden of the Czech population from general environment In 1994-2003, the median blood Cd levels ranged in the interval 0.9-0.4 microg/l blood, in smokers being more than double that in non-smokers. Blood Cd levels detected indicate slightly decreasing trend as well as urine Cd levels (range of median values 0.44-0.28 microg/g creatinine). Since 1996 the levels in children have been found in more than 50% cases below the detection limit of the methods used. The estimated total cadmium intake in the Czech urban population does not signalize any increased risk of health impairment considering non-carcinogenic effects.

Quality control materials for the determination of trace elements in airborne particulate matter.

The development of quality control materials for the determination of selected trace elements in air pollution studies is described. Three types of test samples were prepared for proficiency testing: (1) filters loaded with PM10 fraction of urban air particulate matter (APM) using high-volume air samplers, which were subsequently divided into smaller sections, (2) a bulk sample of APM collected in an automobile tunnel in Prague, and (3) simulated air filters loaded with APM using a wet deposition process. Homogeneity of the test samples was studied using instrumental neutron activation analysis, proton induced X-ray emission and atomic absorption spectrometry, and inductively coupled plasma optical emission spectrometry and mass spectrometry. Sufficiently homogeneous samples were prepared by all three procedures. The simulated air filters appeared to be the most suitable test samples for proficiency testing.

Copper saturation pathways of the urban population in the Czech Republic.

The estimation of the copper saturation pathways of the Czech urban population is presented. The data on copper concentrations proceed from the System of monitoring the environmental impact on population health in the Czech Republic in the period 1994-1998. The copper concentrations were monitored in foodstuffs from the commercial network, in drinking water at the outlets of the waterworks and in the public water main networks, and in the ambient air. The copper levels were measured also in biological material to obtain the data on the copper saturation of the population under monitoring. The copper intake from foodstuffs and drinking water did not vary significantly either in the particular years of monitoring or individual cities. The same concerns also the copper levels in biological material. The total copper intake for an average adult was estimated to be 20.2 micrograms/kg b.w./d., i.e. 1300 micrograms/d. Over 99% of the total intake was that from the diet. The exposure from the intake of drinking water as well as from ambient air was low. The total daily intake lies in the interval 1000-2000 micrograms/d which is usually found in the similar studies of the copper intake. It represents only 40% of the daily dietary copper intake recommended by the JECFA FAO/WHO Commission, 1982. The copper levels in biological material did not differ from the reference values, and did not indicate any evincible hyposaturation of the population with copper.

[The weakening of the inhibition of the H-reflex in patients who have had a stroke and its relation to spasticity of the skeletal musculature]. / Oslablenie tormozheniia H-refleksa u bol'nykh, perenesshikh mozgovoi insul't, i ego sviaz' so spastichnost'iu skeletnoi muskulatury.

Inhibition of the soleus H-reflex was studied in hemiparetic postapoplectic patients and in control group of patients without motor disorders. The depression of H-reflex was caused by stimulation of ipsilateral peroneal nerve and presented in two successive waves (D1 and D2). The former of them corresponds to presynaptic inhibition. The size of both waves of inhibition was reduced in postapoplectic patients according to the degree of their muscle spasticity.

[Relationship between decreased presynaptic inhibition and muscle spasticity in patients with a history of cerebral insult]. / Zavisimost' mezhdu oslableniem presinapticheskogo tormozheniia i myshechnoi spastichnost'iu u bol'nykh, perenesshikh mozgovoi insul't.

Stimulation electromyography was used to study inhibition of the soleus muscle H-reflex induced by stimulation of the common peroneal nerve in healthy individuals and in patients who had underwent cerebral apoplexy. Two successive inhibition waves (D1 and D2) were recorded; the first wave demonstrated the development of presynaptic inhibition of group Ia afferent fibers. In post-insult patients the depth of inhibition diminished depending on the degree of the pathologic increase of the tonus of the skeletal musculature. The role of presynaptic inhibition disorders in the pathogenesis of muscle spasticity is discussed.

[Homosynaptic depression of the monosynaptic spinal reflex in healthy people and patients, suffering from a cerebral stroke]. / Gomosinapticheskaia depressiia monosinapticheskogo spinal'nogo refleksa u zdorovykh liudei i bol'nykh, perenesshikh mozgovoi insul't.

Homosynaptic depression of H-reflex was studied in 25 healthy persons and 33 patients with hemiplegia. The mean duration of the homosynaptic depression in healthy persons was 5200 ms. After the initial relative facilitation the time course of the homosynaptic depression corresponded to a logarithmic function of the interval between the conditioning and testing stimuli. The homosynaptic depression in patients with hemiplegia decreased depending on the degree of the muscular spasticity.

[An apparatus for diagnosing necrotic areas of the skeletal musculature of man and animals]. / Pribor dlia diagnostirovaniia nekrotizirovannykh uchastkov skeletnoi muskulatury cheloveka i zhivotnykh.

Modern methods for the evaluation of principal respiration indexes were analysed to formulate the demands for methodological characteristics of the devices used in lung functional diagnosis. As a result the extent of measurement random errors of main respiration indexes, which guarantee the prescribed level of right diagnosis probability are established.