Suchergebnisse

Toxic effects of nanoparticles - differences and similarities with fine particles
There is increasing recognition that nanoparticles may pose a risk to human health. Toxicology studies have indicated that specific properties of nanoparticles drive their toxicity. These properties include surface area and chemistry, size and shape of particles, as well as charge and number, but to a lesser extent, mass. Nanoparticles can influence human health by occupational exposure and by environmental contacts. Uptake of nanoparticles may occur by inhalation, transdermal means and by ingestion. After inhalation, oral administration or parenteral administration, nanoparticles reach the lungs, gastrointestinal tract and brain. It is important to understand the similar and dissimilar features of nanoparticles and fine particles regarding impact on health. The general picture that emerges from experimental animal studies is that, on a mass dose basis, pulmonary toxicity is enhanced when particle size is reduced from the micrometre to the nanometre range. The increase in toxicity appears to be related to the increase in particle surface area. However, different existing materials in the nanometre size exhibit different degrees of toxicity on the respiratory tract. It is not possible to reach generic conclusions about toxicity based on consideration of size alone; the potential toxicity of each individual nanoparticulate material needs to be considered on a case-by-case basis. There is a clear lack of information on the potential health effects of nanoparticles produced for nanotechnologies. These uncertainties arise because of gaps in knowledge about the factors that are essential for predicting health risks — factors such as routes of exposure, translocation of materials once they enter the body, and interaction of the materials with the body's biological systems.

Abstract
Persistent organic pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. The aim of the study was to assess the POP (polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), DDT and their derivatives) levels in blood serum to identify possible risk group workers. Blood serum samples (116 in total) were collected from two groups of employees — electricians, who can come in contact with PCB-containing transformer and capacitor oil, and welders, who were used as a control group. Sample purification was done by double solid phase extraction. The concentrations of POPs in blood serum were determined by gas chromatography with electron capture detector GC/ECD and recovery controlled by internal standard CB-174. None of the 116 samples contained the full range of tested POPs. However, all samples contained at least one of pesticides, and a marker PCB and mono-ortho PCB. Blood serum samples of 52% of electricians and 97.8% of welders contained non-ortho PCB compared to 84% and 74.7%, respectively, for PBDE's. The concentrations of 18 detected PCBs, 4 detected PBDEs and 6 chlorinated pesticides and their metabolites varied in wide ranges and the differences in mean values between groups were not statistically significant (p > 0.05). The estimated concentrations of POPs correspond to the lowest levels detected in other countries. Mean concentrations of low-chlorinated marker PCBs were higher in the electrician group, suggesting that the employment sites are contaminated with PCBs, or that employees have contact with PCB-containing items.

Health disorders of the employees exposed to organic solvents at work
The aim of the study was to investigate the impact of exposure of organic solvents at work on related health disorders in Latvia. Two surveys were carried out with a total number of 2520 respondents. Retrospective analysis of incidence of occupational diseases caused by organic solvents was performed. 21.4% of employees indicated absorption of chemical substances through skin. The incidence of occupational diseases caused by organic solvents has a stable trend to decrease from year 2003. 58.8% of employees believe that their long-term health disorders are related to their work environment or work conditions. While organic solvents remain an essential working risk problem in Latvia, the data on exposed persons and their health disorders caused by organic solvents are not sufficient enough. Biological monitoring could facilitate early diagnostics of non-specific health disorders caused by organic solvents.

Possible hazards of work environment in metal processing industry in Latvia
The aim of this study was to investigate risk factors in the work environment of Latvian metal processing industry using the database of the Laboratory of Hygiene and Occupational Diseases of the Institute of Occupational Safety and Environmental Health, Rīga Stradiņš University. During the period between 1996 and 2005, 703 measurements were made in metalworking enterprises. In Latvia, approximately 2.4% of the workforce is involved in the metal processing industry. Physical (noise, lighting, vibration) and chemical (abrasive dust, welding aerosol and contained metals) risk factors were analysed. In the assessed metalworking workplaces, the work environment was estimated to be of poor quality, because occupational exposure limits or recommended values were exceeded in 42% (n = 294) of cases. Noise, manganese and welding aerosols most often exceeded the occupational exposure limits or recommended values, the significance was P < 0.001, P < 0.01 and P < 0.05, respectively.

Effects of art therapy on stress and anxiety of employees
The study was designed to determine if art therapy has any effect on the stress and anxiety of employees. The results demonstrated that before and after art therapy in the study group, the level of the stress indicator (cortisol) over twenty-four hours and also the state of anxiety decreased significantly (P < 0.05). The mean final stress level and situational anxiety for the study group were significantly lower (P < 0.05) than those for the control group. No significant changes were found for trait anxiety in any of the groups. These findings suggest that art therapy for employees is a preventive measure for a person to understand stress situations and to be capable to manage their anxiety, react adequately and to cope with stress, thus improving the quality of life by creative means.

Abstract
Humans are exposed to chemicals and PM (particulate matter), including ultrafine particles (nanoparticles), mainly through inhalation. This creates a risk to their health. Another effect to exposure is expression of cytokines and their role in lung inflammation and morphpathogenesis. We conducted a pilot project based on testing of realistic exposure scenarios by describing morphological changes of the respiratory tract in Wistar rats (male) during a 30-day exposure in office where there was high intensity of printing activities. Tracheal tissue of experimental animals had increasing concentrations of inflammatory interleukin IL-1 and decreasing concentrations of IL-6 and TNF-α. The lungs of the experimental animals tended to show focal infiltration of inflammatory cells, vascular plethora, focal and/or diffuse localisation of lymphatic nodules, and also vascular sclerosis and focal emphysema. The results suggested potential dangerous and adverse effect of poor indoor air quality (particles, including nanoparticles, and chemical compounds) on respiratory tract tissue of rats.

Organic solvents as chemical risk factors of the work environment in different branches of industry and possible impact of solvents on workers' health
The aim of our study was to investigate organic solvents as chemical risk factors of the work environment in different branches of the industry in Latvia during 1998-2006 and to evaluate the possible impact of solvents to worker health according to the exposure index. The work conditions were studied in 116 enterprises of different branches of industries in Latvia. The analysis of 1790 measurements showed that organic solvents in the work environment have different degrees of exposure probability risk on worker health. The exposure levels in workplaces differ. More than half of surveyed workplaces (56.7%) had a low organic solvent exposure probability level, in 25.2% workplaces it was medium, and in 18.1% workplaces high. The most widely used organic solvents were aromatic hydrocarbons, which was recorded in 35% of the measurements made during assessment of aromatic hydrocarbon group organic solvent exposure in the work environment. In most workplaces several solvents were present simultaneously. Since solvents have a one-way effect on the human body, the actual exposure risk level is higher than shown when evaluating the exposure index of a single solvent only.

Abstract
There are many factors that affect the well-being and health of employees and the productivity of organisations. The aim of this study was to determine the impact of the Metal Age training programme (MA®) on the well-being of office workers, including investigation of work ability, the stress-causing factors and role of leadership. The study was carried out using questions from four international questionnaires about stress, leadership, and work ability. The intervention group had a training course between the surveys using the ME® method. Several employee stress-causing factors were identified: bad relationship with their workmates was mentioned by 94% of workers; competitive and strenuous atmosphere — by more than 80%; psychological violence or bullying at the workplace by more than 80%, and more than 75% of employee's could not relax after work. Wellness and microclimate in the workplaces were on a relatively high level: the average rating of seven Kiva questions was 7.5. The respondent attitude after ME® did not change significantly. Latvian office workers displayed moderate and good work ability (Work Ability Index, WAI 34.5–38.6). The best work ability was shown in the age group from 20 to 49 (WAI 34.8–39.4); work ability decreased with age. The best correlation was observed between Work Ability Index and "get into situations, that invoke negative feelings" (r = 0.26) and "carrying out ongoing tasks because of other intervening or more urgent matters" (r = −0.24). After ME® the reaction to some stress-causing factors was improved.

Estimation of risk factors of the work environment and analysis of employees' self estimation in the wood processing industry
The aims of our study were to determine risk factors of the work environment in the wood processing industry in Latvia during 1998-2006, to conduct a survey and self- evaluation of health of the employees and to elaborate a set of preventive measures for improvement of the work environment. The work conditions in wood processing companies in Latvia over the study period were poor; of a total of 940 evaluated workplaces/processes in more than one half of cases (n = 483), the risk factors of the working environment exceeded the occupational exposure limits. Measurements made in wood processing and furniture manufacturing most frequently limiting values or recommended values of the occupational exposure were exceeded for noise, indoor air, lighting, welding spray, whole-body vibration, wood dust and other risk factors. Self-evaluation of health by employees indicates that the main health problems were pain in the back and joints, poor hearing, eye irritation, skin irritation and inflammation, chronic coughing, rhinitis, recurring windpipe inflammations, and frequent headaches. Self-evaluation of employees indicated poor diagnostics of occupational diseases and work related diseases as for 82% of the respondents with health complaints they were not confirmed with medical diagnosis.

Evaluation of work conditions and occupational health risk factors in enterprises within a 10-year period in Latvia
The objective of the study was to conduct a survey in the field of occupational health and safety the results of which could be used in rational and effective decision making for elaboration of employment and social policy programmes and for ensuring occupational safety and health programme development. During the study the following groups of people were surveyed: employers, occupational health and safety specialists, and employees. The traditional work risk factors (physical, chemical, biological) have changed to new risks (psychosocial, ergonomic, microclimatic) in Latvia today. The study included objective assessment of occupational health and safety situation (analysis of work environment risk factors measurement data bases, information on occupational diseases, workplace accidents). Results of measurements showed that one-third of measured risk factors values exceeded mandatory or recommended limits but situation has been improved during the last years (2002 compared to 2006). The results of surveys reveal insufficient assessment of risk factors in workplaces and selection of most hazardous ones only. Awareness and understanding of employers and employees regarding occupational health and safety requirements was dissatisfactory. The results of the study reveal a low level of workplace accidents compared to other countries within EU, which may be the result of poor registration system in Latvia. Strengthening of occupational safety and health normative basis and improvement of qualification of occupational physicians has increased the number of occupational diseases and patients revealed for the first time from 1996 to 2006. Early diagnose of occupational diseases and effective rehabilitation is an important question to favour a more rapid return of workforce after occupational morbidity. Study showed that attention should further be paid to simplification of legal requirements, development of alternative methods for informing and educating people, as well as recurrent definition of national indicators to assess efficacy of implemented measures related to occupational health and safety.