Effect of cold conditions on manual performance while wearing petroleum industry protective clothing

The purpose of this study was to investigate manual performance and thermal responses during low work intensity in persons wearing standard protective clothing in the petroleum industry when they were exposed to a range of temperatures (5, -5, -15 and -25℃) that are relevant to environmental conditions for petroleum industry personnel in northern regions. Twelve men participated in the study. Protective clothing was adjusted for the given cold exposure according to current practices. The subjects performed manual tests five times under each environmental condition. The manual performance test battery consisted of four different tests: tactile sensation (Semmes-Weinstein monofilaments), finger dexterity (Purdue Pegboard), hand dexterity (Complete Minnesota dexterity test) and grip strength (grip dynamometer). We found that exposure to -5℃ or colder lowered skin and body temperatures and reduced manual performance during low work intensity. In conclusion the current protective clothing at a given cold exposure is not adequate to maintain manual performance and thermal balance for petroleum workers in the high north.     

Work load and physiological responses during asbestos removal with protective clothing

Summary The removal of asbestos-containing building materials requires the use of dust-repelling protective clothing and a respirator. The present study was aimed at measuring physiological responses to asbestos removal in actual work situations. The subjects were eight asbestos workers. During the work, the men wore permeable or impermeable clothing along with a powered or non-powered filtering device including a full-face or half-face mask. Environmental parameters, work postures, heart rate (HR), the skin temperature at two sites and the rectal temperature were recorded every minute during work. Perceived exertion, thermal sensation, thermal comfort, and skin wetness were rated by the subjects. The ambient temperature at work sites ranged from 19° to 37.5°C and relative humidity, from 21% to 50%. The mean HR ranged from 101 to 141 beats min^–1. The calculated (from HR measurements) average oxygen consumption (VO₂) varied from 0.9 to 1.9 1 min^–1 , which corresponded to 27%–60% of the maximal value. The peak rectal temperature and the highest mean of two measurements of skin temperature were 37.7° ± 0.3° C and 34.4° ± 0.9°C, respectively. The sweat rate varied from 162 to 583 g h^–1. Poor work posture was common during asbestos removal. The arms were elevated over shoulder level for 35% of the work time. During the work the mean physiological strain was considered to be moderate, with some heavy peak loads being registered. The increases in HR and the thermal responses seemed to be due primarily to the use of simple, nonpowered hand tools, which often required the performance of heavy manual work with the arms held above shoulder level, and less to the protective clothing used. The heat strain during asbestos removal was not excessive because most of the work was done under thermoneutral conditions, and a rest pause of 10–15 min every hour also decreased the thermal strain during work. Improvements in work methods and tools are needed to reduce the peak loads and postural strain experienced during asbestos removal.This study was financially supported by the Finnish Work Environmental Fund     

Modeling the chemical protective performance of NBC clothing material

The heat load, imposed by air-permeable NBC (nuclear, biological, and chemical)-protective suits, can be reduced by improving the air permeability of the suit. However, increased air permeability will reduce the chemical protective performance, since increasing the air permeability of the NBC-protective material will result in higher air velocities through the material. In this study the relation between the chemical protective performance and air velocity through NBC-clothing is evaluated. A theoretical model was developed that describes the chemical protection of air permeable NBC-protective clothing material under various conditions. The initial breakthrough concentration and the 50% breakthrough time are modeled as function of parameters like the air velocity and the challenge concentration. Using this model, the effect of airflow through the material on the breakthrough concentration of mustard vapor was calculated and compared with results of breakthrough experiments. The predictions of the model are in good agreement with the experimental results. The air velocity through the material and thus the air permeability of the material appear to be parameters of critical importance. High air velocity through the material results in high breakthrough concentrations, and therefore poor protective performance of the material. To describe the total breakthrough curve, a semiempirical model of experimental breakthrough results was made. This model describes the total breakthrough concentration of vapor through NBC-protective material as a function of parameters like the air velocity and the challenge concentration. This model can be used as a tool to optimise the protective performance of NBC-protective clothing material.     

Aerosols and protective clothing

A complex test method for evaluating protective apparel in aerosol hazard conditions has been developed and examined under laboratory conditions. The effectiveness of the barrier or "collection efficiency" of aerosol protective apparel (APA) depends upon its structural properties such as porosity, thickness, and permeability as well as on its hydrodynamic properties, i.e., pressure drop. Aerosol generating systems and methods of measuring penetration and evaluating data are described. A method of testing protective apparel materials using a standard asbestos aerosol then is described and discussed in detail.     

Anemia associated with exposure to lindane

A recent case of severe, but reversible, hypoplastic anemia was associated temporally with lindane exposure. A series of 46 cases of hematotoxicity associated with lindane is reviewed, and the weaknesses in the indictment of lindane as the causative agent are pointed out. A more rational policy for control of agents suspected of damaging bone marrow awaits improved understanding of pathogenetic mechanisms.     

Dicofol exposure to Florida citrus applicators: Effects of protective clothing

Mixer-loaders and applicators of the pesticide dicofol in Florida citrus groves were monitored for exposure. Alpha-cellulose pads were placed inside and outside regular work clothing. When protective suits were in use, pads were also placed outside the suit. Dicofol accumulation rates were measured when gloves and/or facemasks were worn. Hand rinses were collected. Results showed that an ungloved, normally attired applicator reduced his total dermal exposure 38% by wearing a disposable Tyvek^® protective suit, 27% by wearing gloves, and 65% by wearing both. Suits reduced total dermal exposure by 40% for mixer-loaders, but the use of gloves led to an exposure increase, probably because the inside of the gloves became contaminated.Florida Agricultural Experiment Station Journal Series No. 6402.     

Reduced work tolerance associated with wearing protective clothing and respirators

This study examined worker tolerance and physiological responses to two levels of work while subjects wore various types of protective clothing and respirators. Nine healthy men (mean age = 24.8 years, weight = 75.3 kg, max VO2 = 44.6 mL/kg/min), experienced with the use of respirators, each performed a randomized series of eight experimental tests, each test scheduled to last 180 min. Work was performed on a motor-driven treadmill at a set walking speed and elevation indicative of either 30% (low work intensity) or 60% (high work intensity) of maximum work capacity for each individual. Four protective clothing ensembles were examined: light work clothing (LIGHT), light work clothing with SCBA (SCBA), firefighter's turnout gear with SCBA (FF) and chemical protective clothing with SCBA (CHEM). Physiological measurements included heart rate, skin and rectal temperature, and minute ventilation. Measurements were obtained every 2.5 min until test termination (tolerance time). If less than 180 min, tolerance time was defined by subjective or objective signs of near maximal stress. Mean tolerance times at the low work intensity were 167, 130, 26 and 73 min, respectively, for the LIGHT, SCBA, FF and CHEM ensembles. At the high intensity, mean tolerance times were 91, 23, 4 and 13 min, respectively. At the low work intensity, heart rate with SCBA rose very slowly during the tests and remained approximately 15 beats/min higher than the heart rate for subjects wearing the LIGHT ensemble. In contrast, heart rate with the FF and CHEM ensembles rose sharply and did not approach steady-state values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Worker exposure to paraquat and diquat

Exposure of workers applying paraquat to fields of tomatoes and citrus, and diquat to waterways containing water hyacinths and hydrilla, was monitored with dermal α-cellulose pads attached at each of ten body locations and with personal air monitors. Estimated total body exposure for tomato applicators was apparently influenced by tractor type. Exposure levels from highest to lowest were: open tractor > enclosed cab tractor ? high-clearance tractor. Citrus applicators' exposure to paraquat averaged 28.5 mg/hr and 12.2 mg/hr, with tank concentrations of 0.11% and 0.07%, respectively. Diquat applicators received minimal exposure. Respiratory exposure was <0.1% of the total body exposure in all experiments. Urine samples collected periodically for all workers were, with one exception, without detectable pesticide contamination. Use of disposable coveralls and regularly washed impermeable gloves should effectively reduce exposure.     

某种正压生物防护服的病毒气溶胶防护性能评价

目的 评价某种正压生物防护服对病毒气溶胶的防护效果.方法 制备Phi-X174噬菌体悬液,在气溶胶密闭舱室内发生Phi-X174噬菌体气溶胶,应用空气动力学粒子分析仪检测粒子直径,在高送风档和低送风档条件下,调节气溶胶密闭舱室内的湿度,用安德森六级采样器采样,通过计数噬菌体噬斑数评价该正压生物防护服对病毒气溶胶的防护效率.结果 Phi-X174噬菌体气溶胶粒子质量中值直径约为0.922 μm,气溶胶粒子本底浓度＞2.0×104个/m3,在不同的测试条件下,该正压生物防护服内病毒气溶胶浓度为0 ～21PFU/m3,对Phi-X174噬菌体气溶胶粒子防护效率均＞99.9％,送风量(P=0.84)、环境湿度(P=0.33)以及采样时间(P=0.07)对正压防护服防护效率的影响无统计学意义.结论 该正压生物防护服对Phi-X174噬菌体气溶胶的防护效果较好.     

化学防护服及材料研究进展

介绍了化学防护服的分类与使用情况,综述了国内外主流隔绝式防护服与透气式防护服的发展现状,阐述了近年来发展迅速的用于化学防护服的新型防护材料如选择透过膜材料、纳米材料、生物酶材料的研究现状,展望了未来化学防护服将向多功能化、舒适化、智能化方向发展.     

Biological monitoring of exposure to organophosphorus insecticides by assay of urinary alkyl phosphates: influence of protective measures during manual operations with treated plants

Biological monitoring was carried out by assaying urinary dimethylated alkylphosphates [dimethyldithiophosphate (DMDTP), dimethylthio-phosphate (DMTP), and dimethylphosphate (DMP)] in 11 workers exposed to chlorpyrifos-methyl and azinphosmethyl during operations in a previously sprayed peach orchard. The subjects were divided into groups on the basis of the protective clothing worn. The results were compared with those of a reference group of 99 subjects not occupationally exposed to organophosphorus insecticides. The hand-wash liquid of the workers was also analyzed to evaluate skin contamination. Significantly higher levels of urinary excretion of alkylphosphates were found in all groups than in unexposed controls (Student's t test). A good correlation was found between quantities of the active ingredients on the hands and urinary excretion of total dimethylated alkylphosphates (r = 0.788) and of DMTP (r = 0.749) and DMP (r = 0.790) alone. The correlation between azinphos-methyl on the hands and urinary excretion of DMDTP was poor (r = 0.069). Under the working conditions investigated, the main route of absorption seems to be via the skin. Respiratory absorption, however, also appears significant in view of the difference in urinary excretion of dimethylated alkylphosphates found between subjects with and without face masks.     

Physiological strains of wearing aluminized and non-aluminized firefighters' protective clothing during exercise in radiant heat

This study examined the influences of aluminized (Type A) and non-aluminized firefighters' protective clothing (Type B, C, D and CON) on physiological and subjective responses in radiant heat. Total clothing weight was 6.24, 6.38, 6.06, 5.76 and 3.82 kg for Type A, B, C, D and CON, respectively. Eight firefighters performed exercise at an air temperature of 30°C with 50%RH. Three bouts of 10 min-bicycle exercise in radiant heat (a globe temperature of 70°C) was spaced by a 10 min rest with no radiant heat. Results showed that rectal temperature, mean skin temperature, heart rate, and body weight loss were significantly greater in Type A than in other types (p<0.05). For Type A, thermal gradient of the body reached 0.0 ± 0.7°C, heart rate showed a maximum level of 183 ± 11 bpm and 1.9% of body weight was lost due to sweat secretion. Firefighters felt the hottest and most discomfort in Type A. It appeared that firefighters' thermoregulatory mechanism was severely challenged by wearing aluminized protective clothing during exercise in strong radiant heat. Therefore, it is suggested that the safe upper limits while wearing aluminized firefighters' clothing should be distinguished from those for typical firefighters' protective clothing.     

Long-term exposure to wood-preserving chemicals containing pentachlorophenol and lindane is related to neurobehavioral performance in women.

BACKGROUND: The adverse neurobehavioral effects of long-term low exposure to wood-preserving chemicals (WPC) containing solvents, pentachlorophenol (PCP) and gamma-hexachlorocyclohexane (gamma-HCH; lindane), and other neurotoxicants were investigated in a neuropsychological group study. METHODS: Out of a population of 2,000 women visiting the outpatient practice of a gynecological department, a sample of 15 women aged 31-56 (mean 43) with long-term exposure to WPC verified by self-report, biological monitoring, and environmental samples was investigated. Fifteen controls aged 42 (31-56) years were drawn from the same population and pair-wise matched with respect to sex, age, education, and estimated intelligence. RESULTS: For the exposed group, mean PCP serum level was 43.6 micrograms/l and mean gamma-HCH blood level was 0.085 microgram/l. Mean duration of exposure was 10 (5-17) years. Intellectual functioning, attention, memory, and visuo-motor performance were examined, suggesting significant group differences in visual short-term memory (Benton Test; d = 1.5, P = .005), verbal memory (paired associate learning and Peterson paradigm; d = 4.3 and 1.6, P < .001), and an incidental learning task (d = 2.3; P = .001). Frequent subjective complaints as assessed by questionnaire were attenuated motivation (d = 1.7; P = .001), increased fatigue (d = 1.6; P = .001), distractibility (d = 1.0; P = .003), and depressed mood (d = 1.9; P = .004). PCP blood level was significantly associated with paired-associate learning, Benton Test, and reading/naming speed. CONCLUSIONS: Long-term low-dose exposure to WPC in the domestic environment could be related to subjective complaints (attention, mood, and motivation) and to subtle alterations of neurobehavioral performance (e.g., working memory) in women.     

Occupational exposure to lindane: clinical and laboratory findings

Czeglédi-Jankó, G., and Avar, P. (1970).Brit. J. industr. Med.,27, 283-286. Occupational exposure to lindane: clinical and laboratory findings. Workers exposed to lindane for up to two years have been observed clinically, with EEGs and by chemical analysis of whole blood for lindane. In workers with mild but definite symptoms, the concentrations of lindane in whole blood were likely to be greater than 0·02 ppm, a value close to the upper values in members of the general population in Hungary.