Biomedical subjects

H Virokannas

Publications and source records attributed to H Virokannas.

27 records · Page 2Linked to original sources

PubMed1994

Noise and hearing loss in reindeer herders.

Air conduction hearing thresholds were examined in 512 reindeer herders (aged 18-65 years, clinically normal ears) to evaluate the prevalence of noise-induced hearing loss. The hearing thresholds at 6 kHz showed significant noise-type impairment of hearing compared with those in the ISO 7029 standard or a Finnish reference population. The subjects were exposed to noise mainly in the use of snowmobiles and chain saws: daily noise exposure ranged from 93 to 104 dB(A). The age adjusted hearing thresholds deteriorated with the total noise exposure time, especially at 3 and 4 kHz. The prevalence of significant (class IV) hearing loss was 15% and impairment of hearing was frequently found even in the younger age groups. Although the use of ear protectors seems to be increased among reindeer herders, it still appears to be insufficient, and efforts to promote their use are needed.

Adult↗

PubMed1994

Assessment of cold stress in outdoor work.

The evaluation of cold stress in working life was done in 13, mainly outdoor, occupations and 143 workers using local temperatures, body cooling and thermal sensations. The subjects in the study were young, healthy men and they wore the type of winter clothing generally used in those ambient temperatures (+6...-29 degrees C), for in a work load of from 112 to 480 W. Local temperatures on finger skin indicated that manual dexterity was often reduced in outdoor work. A risk of frostbite was frequently found on the cheek and the wind chill index predicted the risk quite well. Body cooling was often temporarily too high when measured by heat debt and mean skin temperature. Thermal sensations were cool or cold occasionally in 28% of the workers interviewed. The insulation of clothing worn was often lower than the IREQmin-value recommends. The results showed that in outdoor work in winter time cold stress frequently reduced (70%) working ability at least for a short period. Mean skin temperature seems to be, in practice, a useful indicator for body cooling and the IREQmin-value was suitable, especially in light work, to indicate body cooling. A very sensitive factor for the expression of cold stress was finger temperature, at least as an indicator of finger dexterity. Due to the adverse health effects found the cold stress should also be evaluated more systematically in occupational health and safety with health examinations, with protective clothing and technical preventive means.

Adult↗

PubMed1993

Risk of frostbite in vibration-induced white finger cases.

The rate of frostbite was examined with questionnaires filled by 1095 reindeer herders frequently exposed to cold, in particular in driving snowmobiles in the winter. Altogether 443 frostbite injuries, most (72%) of them on the face, had occurred during the last two years, especially when driving a snowmobile. The prevalence of vibration-induced white finger (VWF) was 22%. In this VWF group (N = 243) the cumulative incidence rate in two years of frostbite injuries on the extremities was 27% and in the non-VWF group (N = 852) only 5%. There was no difference in the incidence of frostbite on the face and ear lobe. The amount of frostbitten subjects, with respect to both frostbite on the extremities and head, was significantly associated with the use of snowmobiles during the last two years. According to the results VWF cases have an increased risk of frostbite in the extremities on a cold environment.

Adult↗

PubMed1992

Vibration perception thresholds in workers exposed to vibration.

The vibration perception thresholds (VPT) at six frequencies from 16 to 500 Hz were examined in 77 workers exposed to hand-arm vibration and in 77 controls using a limits procedure. A dose-response relationship between VPTs and exposure to vibration was found, and the age-adjusted VPTs at each frequency were higher in workers exposed to vibration than in controls. Carpal tunnel syndrome (at 250 Hz) and consumption of alcohol (at 125 Hz) significantly increased the VPT, but vibration-induced white finger was not correlated with VPT. Indices for low (16 and 32 Hz) and high (63-500 Hz) VPT frequencies were calculated to evaluate the entire vibrogram, which consisted of several frequencies with two numbers. The results showed that hand-arm vibration disturbs first the high frequencies, and that the disturbance spreads thereafter to the low frequencies. The characteristics of the VPT test regarding vibration exposure and the association between VPT and nerve symptoms in the hand support the view that VPT is a useful measure for vibration-induced sensory nerve damage.

Arm↗

PubMed1991

Finger blood pressure and rewarming rate for screening and diagnosis of Raynaud's phenomenon in workers exposed to vibration.

Both the finger systolic blood pressure (FSP) and the rewarming test of finger skin are measures of circulation in the finger; the first reflects the vasoconstriction phase and the second the vasodilatation phase. The combinations of the specificity and the sensitivity of these methods were evaluated by a receiver operating characteristic curve (ROC). The material included 37 vibration-induced white finger (VWF) cases, five primary Raynaud's cases, and 37 controls. The specificity of the FSP test was high with regard to the anamnesis of white finger and the test was useful for the diagnosis of Raynaud's phenomenon, but the sensitivity was too low for screening. The rewarming test was useful for screening primary Raynaud's case and possibly for screening disorders in peripheral vasodilative function. The connections between the rewarming test and VWF are not clear and according to the present study the rewarming test was not suitable for screening VWF.

Adult↗

PubMed1991

Frostbite in reindeer herders.

The aim of this study was to determine the prevalence of frostbite among reindeer herders and to clarify the co-factors that may relate to these injuries. 2081 (60%) male reindeer herders in Finland were asked information on frostbite. Logistic regression analysis was used for studying the effect of potential co-factors. 453 men (22% of the respondents) reported frostbites during the last twelve months, the areas most affected being the face, fingers and toes. The amount of time spent in snowmobile driving, white finger symptom and the area of reindeer herding proved to be significant explanatory factors. Since the majority of frostbites were associated with snowmobile driving in spite of protection and adaptation to cold, it seems that new technology has not solved all the problems of the working conditions in a cold environment.

Adult↗

PubMed1990

Cardiovascular reflexes in workers exposed to hand-arm vibration.

In the present study autonomic function was observed by measuring cardiovascular reflexes. The quiet breathing test, the deep breathing test and the Valsalva manoeuvre were used. The aim was to study the effects of long-term exposure to hand-arm vibration on the cardiovascular reflexes. The study group included 47 workers (lumberjacks and railroad workers) who were exposed to hand-arm vibration. 36% of the subjects had vibration induced white finger (VWF). Comparisons were also made with 5 primary Raynaud's cases. The changes of the R-R interval in the quiet and deep breathing tests had a significant negative correlation with the ages of the subjects. In all the results there was no evidence that hand-arm vibration could cause autonomic dysfunction in general, but there were signs that it could reduce the autonomic function among workers who are susceptibility to developing white finger reactions. Also, it is possible that the primary Raynaud's cases had reduced cardiovascular reflex responses.

Adult↗

PubMed1989

[Cold weather work].

Explore the source record for details and available documents.

Body Temperature Regulation↗

PubMedDate not supplied

Long-term musculoskeletal disorders and work career in 55-year-old workers.

The purpose of the present study was to describe the associations between long-term disorders of musculoskeletal system and work career in elderly workers. The data were obtained by a postal questionnaire and clinical examinations. The study group consisted of 778 elderly urban persons, who were 55 years old and who lived in the city of Oulu in northern Finland. Long-term musculoskeletal disorders were reported by 62% of the women and 57% of the men. The high prevalence of musculoskeletal disorders was significantly associated with heavy physical work. However, job mobility and declining work career were correlated with the occurrence of long-term musculoskeletal disorders in women whereas advanced work career was connected with a low prevalence of long-term musculoskeletal disorders.

Chronic Disease↗