Documents American Industrial Hygiene Association Journal 10 results

"Injuries and disorders caused by overexertion and repetitive motion are the leading causes of compensable lost-time cases in the United States. Epidemiological and laboratory-based research methods have been used to evaluate the significance of various risk factors associated with overuse injuries and disorders. The National Institute for Occupational Safety and Health performed a comprehensive review of over 600 epidemiological studies in 1997 and concluded that there was evidence of a causal relationship between workplace exposures to forceful exertions, repetition, awkward posture, and vibration and disorders of the neck, shoulder, and upper extremities. Although epidemiological studies provide important insights to understanding the causes of work-related overuse disorders,t hey are sometimes criticized for their inability to measure precisely how people respond to specific risk factors found in the workplace.
This article presents a review of recent laboratory studies and biomechanical models of work factors believed to be associated with increased risk of upper extremity injuries and disorders. Biomechanical models and laboratory studies do not replace epidemiological studies. However, these approaches provide important complementary information that is needed to understand the complex process of how exposures to physical risk factors result in strain that may ultimately lead to injury or disease. These studies also provide important insights as to how people react and respond to specific physical risk factors found in the workplace. Combined with epidemiological research, laboratory studies are an essential element in understanding the causes and prevention of work-related overexertion injuries."

"Injuries and disorders caused by overexertion and repetitive motion are the leading causes of compensable lost-time cases in the United States. Epidemiological and laboratory-based research methods have been used to evaluate the significance of various risk factors associated with overuse injuries and disorders. The National Institute for Occupational Safety and Health performed a comprehensive review of over 600 epidemiological studies in 1997 and concluded that there was evidence of a causal relationship between workplace exposures to forceful exertions, repetition, awkward posture, and vibration and disorders of the neck, shoulder, and upper extremities. Although epidemiological studies provide important insights to understanding the causes of work-related overuse disorders,t hey are sometimes criticized for their inability to measure precisely how people respond to specific risk factors found in the workplace.
This article presents a review of recent laboratory studies and biomechanical models of work factors believed to be associated with increased risk of low-back injuries and disorders. Biomechanical models and laboratory studies do not replace epidemiological studies. However, these approaches provide important complementary information that is needed to understand the complex process of how exposures to physical risk factors result in strain that may ultimately lead to injury or disease. These studies also provide important insights as to how people react and respond to specific physical risk factors found in the workplace. Combined with epidemiological research, laboratory studies are an essential element in understanding the causes and prevention of work-related overexertion injuries."

"The Occupational Safety and Health Administration (OSHA) has regulated occupational exposure to asbestos since 1971. Since issuing its first asbestos standard, OSHA has modified it several times in response to new information about the health risk of exposure and concern expressed by workers and public health groups. As each modification has reduced worker exposure and disease risk, each also has introduced new concepts including emphasis on ancillary provisions in standards regulating occupational exposure to toxic substances to enhance worker health, medical removal protection two attempts at emergency temporary standards; use of historical and objective exposure data to assess worker exposure; the need to eliminate significant risk of disease posed by asbestos; and the presumption of hazard in absence of exposure information. These and other advances have affected all subsequent OSHA standards aimed at reducing occupational exposure to toxic substances."

"The seat vibration of nine tractors was investigated while harrowing was being performed. In all cases, the average vibration of the seat exceeded the 8h "fatigue-decreased proficiency boundary" specified in the international standard ISO 2631/1. The instantaneous accelerations of the most harmful one-third octave band of vibration were sometimes two- to threefold compared with the average. More technical development is needed to reduce seat vibration to a safe level. Topics: agricultural operations; back disorders; backache; drivers; tractors; vibration acceleration; vibration measurement; whole-body vibration."

"A study was conducted in sedentary human subjects of the temperature and humidity conditions under which wearing a respirator mask would be acceptable. Six healthy volunteers were studied during the summer months, when they were used to a hot environment. The experimental room was kept at one of the following combinations of ambient and dewpoint temperatures, in degrees-C: 25:11; 30:13; and 35:16. The subject remained sedentary and was given breathing air via a half facepiece respirator at a temperature of 27, 30, 33 or 36 degrees and a relative humidity of 47 percent (low) or 73 percent (high). Local skin temperatures and dew points were measured at several sites on the body, and the subjects provided ratings of acceptability (defined as desire to change or not change the respirator), thermal sensation, degree of discomfort, perceptions of sweating, and skin wettedness. All six subjects considered the respirator acceptable if the respirator air was 27 or 30 degrees at either humidity level, no matter whether the room condition was hot or not. At each level of environmental temperature, the acceptability of the respirator tended to decrease as either the temperature or the humidity of the respirator air increased. The acceptability of the respirator was related to the lip skin temperature and fell when this temperature exceeded 34.5 degrees or when the dew point of respirator air exceeded 20 degrees. Some subjects commented that they felt that breathing was slightly hard under conditions of high respirator temperature and humidity. High heat or humidity in the respirator air decreased the acceptability of the room environment for each level of room environment. The authors conclude that the heat and humidity conditions inside a respirator influence the acceptability of wearing a respirator. "

"Subjective and physiological responses were obtained from 6 subjects wearing a ventilated face mask while exercising for 15min on a bicycle ergometer. Different combinations of ambient air temperatures (7o, 16o, 25oC) and mask air temperatures (22o, 27o, 33oC) were studied together with two different air humidities inside the mask (61% and 86% RH). Control experiments were performed without the mask. Skin temperatures, heart rates and skin wettedness were monitored during exercise. The subjects' acceptance of the mask and of the thermal environment, thermal sensation, sensations of discomfort, sweating and skin wettedness, and their judgment of the effort involved in breathing were assessed at the end of the 15min exercise period. At ambient temperatures of 7oC and 25oC, the acceptance of the thermal work conditions decreased. In a warm environment a mask air temperature <=27oC was 100% acceptable and increased the acceptance of the thermal environment. In a cool environment, a mask air temperature >=27oC was 100% acceptable. Warm humid air significantly decreased acceptance of the mask conditions."

This paper discusses how health risk assessments have been conducted over the past 10 years and some of their shortcomings. Improved methods and their impact on how exposure limits for air contaminants should be established are also discussed. Examples are given of possible pitfalls in all areas of the assessment process, i.e. hazard identification, dose-response assessment, exposure assessment and risk characterisation. It is concluded that, in future, more enlightened approaches to interpreting animal bioassay data should improve hazard identification, and biologically based disposition and cancer models will provide better estimates of actual cancer risk. Reliance on worst-case exposure scenarios should no longer be necessary in the light of better information on specific exposure parameters and improved data handling methods.

An analysis of benefits versus costs for the industrial hygiene function was tested and verified by interviews with various business personnel, industrial hygienists, health professionals, and lawyers and by a review of litigation literature. The objective of the effort was not to obtain a precise quantification of benefits but to provide information that can be used to improve the influence and scope of the industrial hygiene function. Thus, the analysis may have application for industrial hygienists in the following ways: identifying new functional direction or activities whereby industrial hygiene can better support business objectives; creating a productivity database for hygienists and other health professionals; and justifying changes in resources, personnel, and equipment.

"For many years efforts have been made toward the substitution of less toxic chemicals for particularly toxic ones. Substitutions have been made mainly on the basis of the toxic effect of the virgin compound on humans and the environment, a rationale that may be open to question. This study evaluated a number of substitutions made in recent years. To identify effects on the work and external environments, the chemical products were studied in use within a production system. The main observation was that substitution is a very complex process that might have drawbacks as well as beneficial effects, since new problems may arise through the use of new chemicals. In some cases, knowledge about the extent of these new problems is inadequate, since the substitutions are sometimes not well documented. Substitution may result in reduced use or discontinuance of the original toxic substance and may affect the external as well as the workplace environment."