Moderate cold exposure in the Faroe fishing industry

Differences in female workers' finger temperatures, manual dexterity, ratings on thermal comfort, and local cooling exposure were studied in three factories in the Faroe Island fishing industry. Environmental temperatures in the factories varied from 5 to 19 degrees C with vertical gradients of 7 degrees C/m, and the mean temperatures of the flushing water varied from 2 to 15 degrees C. Finger temperature varied from 12 to 24 degrees C when measured 2 min after work was stopped, and about one-third of the women experienced thermal discomfort in the fingers during work. The fish temperature increased, on the average, less than 1 degrees C during passage through the production room, notwithstanding the thermal differences among the factories. These findings should be used in attempts to reduce the cold exposure of the workers; but also improved control should be recommended for both environmental and water temperatures in the factories.     

Repeatability of grip strength and dexterity tests and the effects of age and gender

OBJECTIVES: Users of hand-held vibratory tools report reductions in grip strength and manual dexterity. This study quantified the test-retest repeatability of grip strength and manual dexterity tests, investigated effects of gender and age, and determined normative measures in different subject groups. METHODS: A total of 72 subjects in four groups (both genders and two age ranges) participated: men and women aged 18 to 25 years and 45 to 55 years. Grip strength was measured with a hand-held dynamometer, and dexterity measured with the Purdue pegboard. We assessed repeatability using one subject group (18 to 25-year-old men) who attended over three successive weeks. RESULTS: Repeated measures of grip strength were correlated for both hands and for each combination of weekly tests (P=0.01), and there were no significant changes in strength over weeks. Repeated measures of dexterity were correlated in both hands (P=0.01) for all test combinations, except between weeks 1 and 3 in the non-dominant hand (P=0.15). Further analysis suggested an improvement in dexterity, consistent with a practice effect. In both age groups, grip strength of the men was significantly greater than that of the women (P<0.01), but there were no gender differences in dexterity scores (P>0.1). There were no significant effects of age for either grip strength or dexterity (P>0.1). CONCLUSIONS: Both tests showed sufficient repeatability, with no age effect on either grip or manual dexterity (between approximately 20 to 55 years), although a decline in grip and dexterity is expected at greater ages. Dexterity scores were similar in both genders for the groups studied. Grip strength was greater in men. Occupational effects might exist for both tests, irrespective of any occupational disorder, and might be reflected in increases or decreases in grip strength and dexterity.     

Diver performance: the effect of cold

Fifteen divers performed five tasks in water of temperatures 20 degrees C and 5 degrees C, using standard scuba equipment. A significant deterioration of performance occurred under the colder condition in: simple arithmetic 13%; logical reasoning 17%; word recall 37%; word recognition 11%; and manual dexterity 17%. Throughout each dive, rectal and five skin temperatures were monitored. Average fall in rectal temperature was 0.5 degrees C during 20 degrees C dives and 1.1 degrees C during 5 degrees C dives. Average body surface temperature fell by 5 degrees C and 12.5 degrees C respectively. Average heat losses calculated from the data were 95 kcal.m(-2).hr(-1) (20 degrees C dives) and 245 kcal.m(-2).hr(-1) (5 degrees C dives). The impairment in word recognition was significantly correlated with the fall in rectal temperature for the 5 degrees C dives. For other tests, the deterioration did not appear to be correlated with body-temperature changes, but rather, occurred rapidly upon cold water immersion. The significance of these findings is discussed in relation to current understanding of the mechanisms by which cold is thought to influence performance underwater.     

Impaired manual dexterity and neuromuscular dysfunction in patients with hand-arm vibration syndrome

Manual dexterity and hand functional difficulties in daily life in hand-arm vibration syndrome (HAVS) were investigated in 29 male patients with HAVS and 30 male controls without occupational exposure to hand-arm vibration. Manual dexterity was assessed by measuring the performance time of picking up and transferring 30 red beans, one by one, from one plate to another. Vibrotactile perception thresholds at 125 Hz and grip strength were also examined. Hand functional difficulties in daily life were surveyed with a questionnaire. The HAVS patients had an increased vibrotactile threshold, decreased grip strength, and low performance in transferring beans. Low performances with transfer times over 53 s (2SD from the mean in the controls) were found in 66% of the HAVS patients and 3% of the controls. Bean transfer times in the patients were correlated with an increasing vibrotactile threshold and decreasing grip strength. The transfer times of the patients were also associated with hand functional difficulties such as picking up coins, turning the pages of a newspaper, buttoning clothes, and pouring from a teapot. The patients with a prolonged transfer time over 60 s (3SD from the mean in the controls) were most likely to have hand functional difficulties. The present findings suggest that measurement of the bean transfer time will serve to assess manual dexterity among HAVS patients, and that impaired manual dexterity in patients may be associated with impaired sensory feedback and muscular dysfunction in the fingers and hands.     

Heat strain in cold

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.     

Grip Strength and Dexterity in Adults with Developmental Delays

The purpose of this study was to determine the usefulness of dexterity and grip strength assessments by comparing the scores of adults with developmental delays with adult norms. A second purpose was to determine the correlations among the assessment instruments. Fifty-six developmentally disabled adults performed the box and block test, the nine hole peg test, and grip strength. Males performed significantly better on grip strength than females, but there was no significant difference on dexterity scores. Males scored significantly lower than established norms on all tests except the left nine hole peg test. Females scores were significantly lower than norms on all tests except the left and right nine hole peg test. Dexterity test scores on one side of the body were highly correlated with those on the other side, but grip strength was not highly correlated with dexterity. This suggests that occupational therap~sts need to treat dexterity and grip as separate entitles. The present results may provide guidelines to determine average performance for adults with developmental delays.     

Cold exposure during helicopter rescue operations in the Western Alps

OBJECTIVE: The study evaluates exposure to the cold of personnel involved in helicopter rescue operations in an alpine environment. METHODS: Rescue operations over a period of 15 months in the Oberwallis region (Switzerland) were analysed with special regard to the weather conditions, the locality and its altitude, and the duration. The equivalent chill temperature was estimated with two independent models. "Mean exposure" as well as the "worst-case situation" (based on maximum windspeed) were calculated. The results were evaluated according to the "classic" Siple-Passel model, the more recent model of Danielsson, ISO 11079, ISO 9920, the German industrial standard DIN 33403.5, and the German government regulations for work in cold environments ("G21"). RESULTS: The temperature models showed only marginal differences in chill temperature. Assuming "worst-case conditions", the Siple-Passel model showed that 87.1% of the operations occurred at chill temperatures > -30 degrees C, 12.1% in the range of -30 to -45 degrees C, and 0.8% at <-45 degrees C. The lowest temperature was -54.6 degrees C. The Danielson model resulted in 77.6% without the risk of frostbite, 20.1% with >5% risk, 6% with >50% risk and 1.8% with >95% risk. According to DIN 33403.5, 1.5% of the operations were performed at chill temperatures higher than cold class 1: 2.3% are class 1, 13.3% class 2, 34.7% class 3, 34.6% class 4 and 13.7% class 5. The maximum exposure times of DIN 33404.5 are exceeded in at least 0.5% of the missions. According to ISO 11079, clothing with 2.0 clo is sufficient in 40.2 and 23.9% of the operations [summer, required clothing insulation (IREQ) min. and IREQ neutr., respectively]. In winter the corresponding results are 0.3 and 0.0%. Duration of limited exposure is exceeded in 9.1 (IREQ min.) and 19.8% (IREQ neutr.) of the operations in summer and in 10.3 and 19.8% in winter. According to ISO 9920, ICL min. as well as ICL neutr. is exceeded in 100% in summer and winter operations. CONCLUSIONS: Alpine rescue operations are typical of a place of work in a cold--sometimes extremely cold--environment. Because of the limited time of exposure during the majority of the operations, the most important danger for rescue personnel is frostbite, although hypothermia cannot be excluded in cases of prolonged operations. Special advice to avoid the specific risks must be given to the crews and an examination by occupational medicine, e.g. according to "Working in cold environments, G21" of the German Berufsgenossenschaften, is recommended. Recommendations for adequate clothing are given.     

扬州市城区学龄前儿童发育性协调障碍的流行病学调查

目的 了解扬州市城区学龄前儿童发育性协调障碍（developmental coordination disorder,DCD）的发病情况,为DCD的早预防、早诊断、早干预提供理论依据。方法 随机整群抽取扬州市城区3所幼儿园1 454名3~7岁儿童,使用儿童运动评估成套试验（movement assessment battery for Children,M-ABC）筛查儿童发育性协调障碍,使用儿童发育筛查测试（developmental screen test,DST）和韦氏学龄前及幼儿智力量表（the Wechsler preschool and primary scale of intelligence,WPPSI）剔除智力落后儿童,采用美国精神病诊断手册第四版（the diagnostic and statistical manual of mental disorders-IV,DSM-IV）确诊DCD。结果 调查发现学龄前儿童DCD异常和可疑率分别为5.2%和12.0%。男童DCD异常及可疑率（7.3%和14.0%）高于女童（2.7%和9.7%）,M-ABC实验得分差异体现在手灵巧度和动态平衡两个方面（均有P<0.001）。不同年龄的儿童DCD异常及可疑率不同（χ2=18.502,P=0.005）,由高到底依次为4~岁组、6~7岁组、5~岁组和3~岁组,M-ABC实验得分差异体现在手灵巧度和目标抓握两个方面（均有P<0.001）。结论 扬州市城区学龄前儿童DCD患病率不容乐观,手灵巧度和目标抓握能力相对落后。应根据不同性别、不同年龄儿童的运动协调发展特点,加强其整体运动协调能力训练。     

Chronic neurobehavioural effects of toluene.

Neurobehavioural tests were undertaken by 30 female workers exposed to toluene and matched controls with low occupational exposure to toluene. The environmental air levels (TWA) of toluene was 88 ppm for the exposed workers and 13 ppm for the controls. The toluene in blood concentrations for the exposed workers was 1.25 mg/l and for the controls 0.16 mg/l. Statistically significant differences between workers exposed to toluene and controls in neurobehavioural tests measuring manual dexterity (grooved peg board), visual scanning (trail making, visual reproduction, Benton visual retention, and digit symbol), and verbal memory (digit span) were observed. Further, the performance at each of these tests was related to time weighted average exposure concentrations of air toluene. The workers exposed to toluene had no clinical symptoms or signs. The question arises as to whether these impairments in neurobehavioural tests are reversible or whether they could be a forerunner of more severe damage.     

Chronic neurobehavioural effects of toluene

Neurobehavioural tests were undertaken by 30 female workers exposed to toluene and matched controls with low occupational exposure to toluene. The environmental air levels (TWA) of toluene was 88 ppm for the exposed workers and 13 ppm for the controls. The toluene in blood concentrations for the exposed workers was 1.25 mg/l and for the controls 0.16 mg/l. Statistically significant differences between workers exposed to toluene and controls in neurobehavioural tests measuring manual dexterity (grooved peg board), visual scanning (trail making, visual reproduction, Benton visual retention, and digit symbol), and verbal memory (digit span) were observed. Further, the performance at each of these tests was related to time weighted average exposure concentrations of air toluene. The workers exposed to toluene had no clinical symptoms or signs. The question arises as to whether these impairments in neurobehavioural tests are reversible or whether they could be a forerunner of more severe damage.     

Validity of infrared tympanic temperature for the evaluation of heat strain while wearing impermeable protective clothing in hot environments

The purpose of this study was to investigate the validity of infrared tympanic temperature (IR T(ty)) as a thermal index to evaluate the heat strain of workers in hot environments, in comparison with rectal temperatures at various depths (T(re-4, -8, and -16) for 4, 8 and 16 cm from the anal sphincter). Eight males underwent twelve experimental conditions: two activities (rest and exercise) × three clothing levels [Control, HDPE (high-density polyethylene coverall) and PVC (polyvinyl chloride coverall) condition] × two air temperatures (25 and 32℃ with 50%RH). The results showed that 1) in the conditions with most heat strain (HDPE or PVC condition at 32℃), IR T(ty) was equal to or even higher than T(re); 2) during exercise, physiological strain index (PSI) using IR T(ty) did not underestimate PSI-values using T(re-16), and overestimated those PSI-values from T(re-16) in HDPE and PVC conditions at 32℃; 3) during exercise, the relationships between IR T(ty) and heart and total sweat rate were stronger than those between T(re-16) and heart and total sweat rate. These results indicated that IR T(ty) is valid as a thermal index to evaluate the heat strain of workers wearing impermeable protective coveralls in hot environments. However, the application of IR T(ty) is limited only for strenuous works wearing encapsulated personal protective clothing with a hood in heat.     

Methylmercury exposure affects motor performance of a riverine population of the Tapajós river, Brazilian Amazon

Gold mining and deforestation in the Brazilian Amazon are increasing mercury pollution of the extensive water system, exposing riverine populations to organic mercury through fish-eating. The aim of the present study was to evaluate the effect of such exposure on motor performance. This cross-sectional study was carried out in May 1996, in a village located on the banks of the Tapajós river in the Amazonian Basin, Brazil. Information concerning sociodemographics, health, smoking habits, alcohol drinking, dietary habits and work history were collected using an interview-administered questionnaire. Mercury concentrations were measured by cold vapor atomic absorption in blood and hair of each participant, of whom those aged between 15 and 79 years were assessed for motor performance (n=84). Psychomotor performance was evaluated using the Santa Ana manual dexterity test, the Grooved Pegboard Fine motor test and the fingertapping motor speed test. Motor strength was measured by dynamometry for grip and pinch strength. Following the exclusion of 16 persons for previous head injury, working with mercury in the gold-mining sites, or for diabetes, the relationship between performance and bioindicators of mercury was examined using multivariate statistical analyses, taking into account covariables. All participants in the study reported eating fish, which comprised 61.8% of the total meals eaten during the preceding week. The median hair total mercury concentration was 9 μg/g. Organic mercury accounted for 94.4 ± 1.9% of the total mercury levels. Multivariate analysis of variance indicated that hair mercury was inversely associated with overall performance on the psychomotor tests, while a tendency was observed with blood mercury. Semipartial regression analyses showed that hair total mercury accounted for 8% to 16% of the variance of psychomotor performance. Neither hair nor blood total mercury was associated with the results of the strength tests in women and men. Although dose-effect relationships were observed in this cross-sectional study, they may reflect higher exposure levels in the past. The findings of this study demonstrated neurobehavioral manifestations of subtle neurotoxic effects on motor functions, associated with low-level methylmercury exposure. Received: 10 December 1998 / Accepted: 2 November 1999     

Hypothermia-related deaths--United States, 2003-2004

Hypothermia, a reduction in the body's core temperature to <95.0 degrees F (<35.0 degrees C), is a preventable medical emergency usually caused by prolonged exposure to cold temperatures without adequate protective clothing. Warning signs and symptoms of hypothermia include lethargy, weakness and loss of coordination, confusion, uncontrollable shivering, and reduced respiratory or heart rate. Common risk factors are advanced age, substance abuse, altered mental status, and increased contact with substances that promote heat loss, such as water. This report describes three hypothermia-related deaths that occurred in the United States during 2003-2004, summarizes hypothermia-related mortality during 1979-2002, describes risk factors for and symptoms of hypothermia, and reviews measures to prevent hypothermia-related injury and death. Public health strategies tailored to persons at increased risk for exposure to excessive cold might help reduce hypothermia-related morbidity and mortality.     

Feeling cold at work increases the risk of symptoms from muscles, skin, and airways in seafood industry workers

BACKGROUND: Norwegian workers in seafood industry plants are exposed to a cold and often wet environment. METHODS: 1,767 seafood industry workers participated in a questionnaire study. Seventeen plants were visited for thermal measurements. RESULTS: 15.9% of industrial workers and 1.7% of administrative workers reported that they often felt cold at work. Mean finger temperatures after 1 hr work varied between 16 and 22 degrees C. Foot temperature dropped from morning measurement until lunch time in 85% of the measurements. Industrial workers who reported that they often felt cold, had significantly increased prevalence of symptoms from muscles, skin, and airways while working, compared to workers who reported that they never felt cold at work. CONCLUSIONS: Moderate cooling, caused by a cold indoor working environment, may increase muscle-, airway-, and skin symptoms. The prevalence of feeling cold may be a useful exposure estimate in moderate cold exposure situations.     

The effect of microbiological containment systems on dexterity

Microbiology laboratories use containment equipment such as safety cabinets and isolators or respiratory protective equipment to protect workers against aerosol infection hazards. There is a perception among microbiologists that the use of containment equipment reduces dexterity to a point where the risks associated with using sharps are increased. Thus, in a situation where it is essential to use sharps, the use of respiratory protection is frequently the favored method of operator protection. Using three methods of manual dexterity testing, the effect of latex gloves, a positive pressure respirator, and three forms of containment equipment, (a Class II safety cabinet, a half suit, and a flexible film isolator) were tested against performance in these tests using bare hands in 10 subjects. The study was extended to additionally assess Class III cabinets using 20 subjects. With the exception of latex gloves, the personal protective equipment and containment equipment all had a statistically significant detrimental effect on manual dexterity compared with working solely with bare hands. The use of containment systems, especially barrier containment systems such as Class III cabinets and isolators, significantly reduces dexterity and may increase the chance of accidents. The use of positive pressure respirators with double gloves also affects dexterity but to a lesser extent. The use of sharps should be minimized within containment equipment. Risk assessment may be required to address the comparative risk of aerosol and needlestick infection with different agents to choose the most appropriate containment systems.     

A new whole-body vapor exposure chamber for protection performance research on chemical protective ensembles

A chemical vapor exposure chamber was designed to permit the study of whole-body vapor exposure of individuals wearing full protective clothing and equipment systems. A methodology also was developed to quantify the vapor protection performance of chemical protective ensembles (CPE) under safe and validated laboratory procedures. The principal research objectives were to (1) provide a methodology to accurately assess the performance of CPE and equipment under different environmental and chemical vapor challenge conditions; (2) quantify the vapor protection on a per body region basis; (3) have a systems level tool to aid in the research and development of more effective CPE for use in chemical biological environments; and (4) have a safe and reliable means of qualifying new CPE on the basis of vapor protection. Although designed for the evaluation of military-style protective equipment, the procedures apply equally to other styles of CPE used by civilian agencies such as firefighters, police, and hazmat units. The chamber and methodology were specifically designed to examine the vapor protection performance of clothing ensembles, including the details of protection variation over the body. A variety of exposure conditions appropriate to indoor and outdoor scenarios are possible, including the effects of wind, temperature, and relative humidity. Protection performance results from a number of individuals wearing typical military-style CPE are presented. These results demonstrate that there is no such thing as a unique protection performance level obtained for a given CPE. Rather, the individual and the ensemble interact differently in each situation, resulting in a protection performance distribution for individuals, and for groups of wearers, even under a standardized set of exposure conditions.     

Comparisons of air and liquid personal cooling for intermittent heavy work in moderate temperatures.

Personal microenvironmental cooling has been used to enhance safety and extend the work capacity of laborers wearing protective clothing. Previous studies of air and liquid cooling have used either very low work rates or high environmental temperatures. Emergency work tasks frequently require high work rates and occur in moderate ambient temperatures. The purpose of this research was to examine the efficacy of intermittent personal cooling during rest and to compare liquid and air cooling systems in subjects engaged in hard work. Fourteen volunteers wearing chemical protective clothing performed treadmill walking at a metabolic rate of 430 W for 45 min followed by a 15-min rest at a wet-bulb globe temperature of 25 degrees C. During rest, volunteers received either no cooling, air cooling, or liquid cooling. Both cooling systems partially alleviated heat strain and increased work time with the air system offering slightly more effective cooling.     

Work-site clinical and neurobehavioral assessment of solvent-exposed microelectronics workers

Twenty-five workers, five currently and 20 formerly involved in the manufacture of hybrid microcircuits, underwent clinical evaluations at the request of a management-union committee concerned about chronic solvent exposures in a research and development laboratory. A battery of neurobehavioral tests was administered to compare the solvent-exposed group with 32 age-, gender-, ethnicity-, and education-matched controls. The tests included: MMPI-I, hand grip strength, tactile sensitivity, dexterity, color discrimination, visual acuity and contrast sensitivity, and tests selected from the computerized Neurobehavioral Evaluation System (NES2). Clinical narratives and retrospective exposure assessments in the study group suggested chronic low-level exposure to solvents, with intermittent acute excursions. Work-related diagnoses included upper respiratory mucosal irritation and sinusitis (44%), lower respiratory reactive airway-disease (12%), and dermatitis (5%). Three workers (12%) had findings consistent with a solvent-induced encephalopathy. Significant differences (after Bonferroni correction) were found between the two groups on 5 of 11 NES subtests: symptom scale, mood scale, finger tapping, simple reaction time, and symbol-digit substitution. Differences also reached significance for overall vibration sensitivity thresholds, visual contrast sensitivity, and grip strength. The MMPI average clinical scale elevation was significantly higher in the exposed group than controls. These results support an association between chronic low-dose solvent exposure and measurable neurobehavioral changes.     

职业性混苯暴露工人神经行为功能改变

利用世界卫生组织（ＷＨＯ）推荐的神经行为核心测试组合（ＮＣＴＢ）对１０３名职业性混苯暴露工人,以及７２名无职业性有害因素接触的同厂工人进行测试。结果发现：暴露组在情感状态（ＰＯＭＳ）、手工敏捷度、数字广度、数字译码、目标追踪等项目得分都低于对照组,其中优势手手工敏捷度、目标追踪两项得分差异具显著性。按车间混苯浓度分为高暴露组和低暴露组,多因素分析发现：高暴露组情感状态（ＰＯＭＳ）中的抑郁－沮丧和有力－好动、数字广度、手工敏捷度（优势手和非优势手）、数字译码、目标追踪等项显著低于对照组和低暴露组。提示混苯暴露使工人神经行为功能表现某些方面的改变,如心情趋于抑郁、缺乏活动性,短时记忆力、理解力、运动速度、协调性等方面表现较差。