Exposure criteria for evaluating lumbar spine load.

OBJECTIVE: As a part of regular revision of the List of Occupational Diseases in the Czech Republic, efforts have been made to add a new item so that lumbar spine disease caused by overload may be recognized as occupational one, with adherence to the valid national rules, that is, clinical criteria are met and objective assessment confirms working conditions under which, according to recent scientific knowledge, such an occupational disease develops. The aim is to provide information on the use of a proposed method for working condition assessment in a real setting, based on the initial experiences gained from a pilot study carried out to validate the method. METHODS: Working conditions were assessed in 55 individuals with chronic low back pain (25 males, 30 females; mean age 45.6 years; mean length of employment 15.6 years). The assessment was based on estimating compressive force on the L4/L5 intervertebral disc when performing potentially high-risk work tasks which were entered into four types of checklists throughout their work shifts. The compression values were calculated using a special module that was developed. RESULTS: In 24 cases comprehensive assessment of all tasks performed showed fulfillment of the proposed criteria of working conditions needed for recognition of occupational disease. Those included healthcare, foundry and forest workers, production operators, cabinetmakers, locksmiths, bricklayers, etc. In all the cases, lumbar spine overload was associated with work tasks requiring combinations of manual handling of objects and trunk rotation or bending. The criteria were not met in 31 subjects. The mean length of employment was 15.4 and 15.8 years in patients who met and did not meet the proposed criteria, respectively. CONCLUSION: The proposed method proved to be applicable in occupational hygiene evaluation in a real setting.

Evaluation of Lumbar Spine Load by Computational Method in Order to Acknowledge Low-back Disorders as Occupational Diseases.

AIM: The aim of the study was to develop a computational module for the prediction of compressive force on the L4/L5 disc suitable for use in field settings. METHOD: The value of compressive force is intended to be used as a proxy measure of the mechanical burden of low-back when performing work activities. The compressive force predicted by the module in a particular worker should be compared with the NIOSH limit value of 3,400 N for the assessment of lumbar spine load during manual lifting tasks. Exceeding the limit will be considered as the fulfilment of "hygienic criterion" that should be met to acknowledge low-back disorder as an occupational disease. To develop the computational module we used the ergonomic software TECNOMATIX Classic Jack taking into account the anthropometric parameters of a worker and ergonomic parameters of his/her work activity. RESULTS: We calculated compressive forces on the L4/L5 disc in about 1,300 simulated combinations of various factors influencing compressive force. Parameters which turned out to be crucial for the compression of L4/L5 disc were included in the computational algorithm. CONCLUSION: Our study was primarily aimed at the assessment of lumbar disorders as occupational diseases. Moreover, the study can contribute to the recommendation of preventive measures to decrease health risks in occupations associated with the overload of low-back region. The graphic maps generated by the computational module enable a fast and exact analysis of particular job.

LOW-BACK PAIN DISORDERS AS OCCUPATIONAL DISEASES IN THE CZECH REPUBLIC AND 22 EUROPEAN COUNTRIES: COMPARISON OF NATIONAL SYSTEMS, RELATED DIAGNOSES AND EVALUATION CRITERIA.

AIM: Low-back pain diseases (LBPD) belong to the most frequent diagnoses determined by general practitioners, and constitute one of the most common reasons for sick leave and permanent disability pension in the Czech Republic and other European countries. Epidemiological studies have shown a statistically significant association between LBPD and certain types of occupational burden. However, in the Czech Republic, LBPD caused by overload and/or whole-body vibrations have not yet been included in the list of occupational diseases. The aim of this study was to collect and compare the systems, criteria and diagnoses used to recognize LBPD as occupational diseases in other European countries. METHODS: A questionnaire focused on LBPD was distributed and answered by specialists in occupational diseases in European countries. It included items concerning LBPD in the national list of occupational diseases, and work-related and diagnostic criteria that need to be fulfilled for recognizing LBPD as occupational diseases and possible awarding compensations to the patients. RESULTS: In 13 countries out of the 23 countries studied, LBPD caused by overload can be recognized as occupational, providing that the diagnosis is sufficiently proven and exposure criteria and/or listed occupation are met and duration of exposure is confirmed (Belgium, Denmark, France, Germany, Hungary, Italy, Lithuania, Macedonia, Netherlands, Romania, Slovakia, Sweden, and Switzerland). LBPD due to vibrations can be also recognized as occupational in 14 countries. In 8 countries LBPD are not accepted as occupational unless they are caused by an injury at work. Specific criteria to evaluate occupational exposure of patients with LBPD were set in Belgium, Denmark, France, Germany, Lithuania, Macedonia, Netherlands, and Slovakia. In other countries, the evaluation is done at an individual basis. CONCLUSIONS: In practice, the assessment of occupational overload and its contribution to the development of LBPD as well as its inclusion in the compensation system are important for several reasons. Firstly, it may be considered essentially preventable. Secondly, cases with a significant contribution of occupational aetiology may be viewed as occupational diseases for which compensation may be claimed, as it is the case in many European countries. Importantly, inclusion of LBPD in the list of occupational diseases or another system of compensation may be viewed as a preventive measure as it increases the visibility of this problem not only for the workers, but especially for the employers.

Accumulation of microcystins in Nile tilapia, Oreochromis niloticus L., and effects of a complex cyanobacterial bloom on the dietetic quality of muscles.

The aim of this study was to investigate the kinetics of accumulation and elimination of microcystins in the tissues of Nile tilapia (Oreochromis niloticus) and to evaluate the effect of cyanobacterial exposure on fish muscle quality (levels of total fat and ash, protein, dry matter and the composition of saturated, monounsaturated and polyunsaturated fatty acids). Fish were exposed for 28 days to a natural cyanobacterial bloom with total microcystin concentration around 1,200 µg g⁻¹ biomass dry weight. The hepatopancreas accumulated microcystins up to 350 ng g⁻¹ fresh weight, but concentrations in muscle were generally below the detection limit (2 ng g⁻¹ fresh weight). Following the exposure, fish were moved to the clean water, but only minor microcystin removal from the hepatopancreas was observed during a 4 week depuration period. Exposures of tilapia to the complex cyanobacterial bloom had only minor and temporary impacts on the investigated parameters of dietetic quality.