Assessment of Airborn Multiwalled Carbon Nanotubes in a Manufactoring Environment.

This study was carried out in a factory producing multiwalled carbon nanotubes (MWCNTs) by the catalytic chemical vapor deposition method in a pyrolysis reactor. Air samples of the personal breathing areas were collected simultaneously on mixed cellulose ester filters, for analysis by transmission electron microscopy (TEM), and on high-purity quartz filters for thermal-optical analysis of elemental carbon (EC). It is found that the production of MWCNTs is accompanied by the release of the MWCNT structures in the air of different working zones. The concentration of respirable aerosol in the personal breathing areas, averaged over an 8-hour period, ranges from 0.54 to 6.11 µg/m3 based on EC. Airborne MWCNTs were found in the form of agglomerates that range in size from about 1 to 10 µm. These data are consistent with measurements in different plants by two other international groups (from the United States and Sweden) using similar methodology (TEM in combination with EC analysis). In the absence of convincing data on the potential health risks of MWCNTs, and following the principle of reasonable precautions, preventive measures should be taken to minimize exposure to these materials.

Carbon Nanotubes Exposure Risk Assessment: From Toxicology to Epidemiologic Studies (Overview of the Current Problem).

Nanoscale size and fiber like structure of carbon nanotubes (CNTs) may determine high reactivity and penetration, as well as the pathogenicity of asbestos and other mineral fibers. Despite many in vitro and in vivo studies, the absence of full-scale data on CNT effects on human health clearly point out the necessity for epidemiological studies. Currently, several projects are initiated worldwide on studying health risks associated with the inhalation of industrial CNTs, including NIOSH-promoted research (United States), the European CANTES study, and the Russian CNT-ERA project. Studies comprising several successive steps, such as CNT exposure assessment in occupational settings, toxicological evaluation, and epidemiological observations, are critical for determining material safety and use criteria.

Evaluation of fibrogenic potential of industrial multi-walled carbon nanotubes in acute aspiration experiment.

Local inflammatory response in the lungs and fi brogenic potential of multi-walled carbon nanotubes were studied in an acute aspiration experiment in mice. The doses were chosen based on the concentration of nanotubes in the air at a workplace of the company-producer. ELISA, fl ow cytometry, enhanced darkfield microscopy, and histological examination showed that multi-walled carbon nanotubes induced local inflammation, oxidative stress, and connective tissue growth (fibrosis). Serum levels of TGF-ß1 and osteopontin proteins can serve as potential exposure biomarkers.

[Evidence-based medicine as a fundamental principle of health care management for workers].

Evidence-based principles in occupational medicine should include prevention, diagnosis, treatment and rehabilitation. Specific feature of occupational medicine is necessity to prove cause-effect relationships between occupational factor and the disease emerged. Important place is occupied by cohort and intervention studies, systematic reviews and meta-analysis. Information obtained by scientific society should be presented to practical specialists and put into everyday activities.

[Influence of occupational stress on health state of energy station workers].

Workers servicing energy stations (113 males) were diagnosed as having specific features of working stress--narrower range of decision latitude. Lower control was associated with lower subjective evaluation of psychologic health according to SF-36, disorders of left ventricle diastolic function, decreased high density lipoproteids content.

Risk factors for first-ever low back pain among workers in their first employment.

BACKGROUND: Low back pain has been estimated to be the most costly ailment of people of working age. Both work characteristics and individual factors have been identified as risk factors. The first interaction between work characteristics and individual factors occurs when workers start in their first job. AIMS: To investigate work-related risk factors for first-ever low back pain in young workers in their first employment. METHODS: A cross-sectional analysis was performed on 278 young workers in their first employment and without a history of low back pain prior to working. Work-related physical factors, psychosocial work characteristics, individual variables and first-ever low back pain were queried by means of a questionnaire. RESULTS: About half of the workers who developed low back pain after job start did so in the first year of employment. An increased risk was observed for (i) long periods of seated work [relative risk (RR) = 3.2, 95% confidence interval (CI) = 1.6-6.4]; (ii) more than 12 flexion or rotation movements of the trunk per hour (RR = 3.0, 95%CI = 1.4-6.4); and (iii) more than 3 years seniority in a job involving lifting more than 25 kg at least once an hour (RR = 3.7, 95%CI = 1.4-9.4). As to psychosocial work characteristics, first-ever low back pain was associated with a combination of low psychological job demands and low supervisor support. CONCLUSION: Work-related physical factors and psychosocial work characteristics should be considered as risk factors for first-ever low back pain. First-ever episodes of low back pain are common in the first year of employment. This may reflect a lack of work experience or training.

[Effects of work at video displays on the state of the nervous system]. / Vliianie raboty s videodispleinymi terminalami na sostoianie nervnoi sistemy.

Videodisplay users were compared with reference group in nervous system state, length of service (under 5 years, 5-10 years, 10 years and more) during prospective observation. The comparison demonstrated reliably high and occupationally induced risk of vegetative dysfunctions. The authors defined correlation of the risk with exposure to 2-400 kHz magnetic fields.

[Exposure to 50 of heart rhythm in power plants personnel]. / Vozdeistvie élektromagnitnykh polei 50 Gts na pokazateli variativnosti serdechnogo ritma personala énergoob''ektov.

The authors first revealed reliable decrease in general capacity and amplitude of electromagnetic waves in staffers subjected to occupational electromagnetic fields of 50 Hz--that proves increased risk of cardiovascular diseases dependent on vegetative matters. Present norms on electric and magnetic fields of 50 Hz should be justified and intensified.

[Physiologic evaluation of permissible work timing at the video display]. / Fiziologicheskoe obosnovanie dopustimoi prodolzhitelnosti raboty za videoterminalom.

The studies covered changes in functional state of 42 programmers working at VGA. All the examinees reported subjective evaluation of fatigue and variational pulsometry before and after the work at VGA, those who worked at the display for 3 hours underwent blood pressure and pulse rate measurements (with subsequent calculation of several hemodynamic parameters) before and after the work. The researchers applied Major Components Method to obtain some integral parameters. The obtained values described initial state of cardiovascular system and changes in autocorellation of some BCG intervals. The fatigue was proved to occur by the end of the second working hour, and by the end of the third hour the examines demonstrated unfavorable changes of functional state (depression of heart activities and increased blood pressure). Only those who worked over 4 hours reported discomfort, so functional disorders appear earlier, than individuals detect them.