History and evolution of control banding: a review.

Control banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents often encountered in the workplace. The original CB model was developed within the pharmaceutical industry; however, the modern movement involves models developed for non-experts to input hazard and exposure potential information for bulk chemical processes, receiving control advice as a result. The CB approach utilizes these models for the dissemination of qualitative and semiquantitative risk assessment tools being developed to complement the traditional industrial hygiene model of air sampling and analysis. It is being applied and tested in small- and medium-sized enterprises within developed countries and industrially developing countries; however, large enterprises have also incorporated these strategies within chemical safety programs. Existing research of the components of the most available CB model, the Control of Substances Hazardous to Health Essentials, has shown that exposure bands do not always provide adequate margins of safety, that there is a high rate of under-control errors, that it works better with dusts than with vapors, that there is an inherent inaccuracy in estimating variability, and that when taken together the outcomes of this model may lead to potentially inappropriate workplace confidence in chemical exposure reduction in some operations. Alternatively, large-scale comparisons of industry exposure data to this CB model's outcomes have indicated more promising results with a high correlation seen internationally. With the accuracy of the toxicological ratings and hazard band classification currently in question, their proper re-evaluation will be of great benefit to the reliability of existing and future CB models. The need for a more complete analysis of CB model components and, most importantly, a more comprehensive prospective research process remains. This analysis will be important in understanding implications of the model's overall effectiveness. Since the CB approach is now being used worldwide with an even broader implementation in progress, further research toward understanding its strengths and weaknesses will assist in its further refinement and confidence in its ongoing utility.

The contribution of occupational risks to the global burden of disease: summary and next steps.

BACKGROUND: The Comparative Risk Assessment (CRA) project of the World Health Organization (WHO) assessed worldwide mortality and morbidity in the year 2000 resulting from exposures to selected occupational hazards. This article summarizes findings of the WHO CRA project, presents the estimates of the International Labor Organization (ILO) for total deaths due to workplace risks, and calls for action. OBJECTIVES: Global burden estimates and counts of deaths assist ministers and other decision and policy makers to make informed decisions and to take action regarding risk reduction. METHODS: The WHO CRA methodology combined the proportions of the population exposed to five occupational hazards (excluding numerous risks due to inadequate global data) with relative risk measures to estimate attributable fractions of the selected health outcomes for both morbidity and mortality. ILO estimates of total numbers of global work-related injury deaths apply national fatality rates to employment data for the particular country; for disease deaths ILO uses an attributable risk approach. RESULTS: In 2000, the selected occupational risk factors were responsible worldwide for 37% of back pain, 16% of hearing loss, 13% of chronic obstructive pulmonary disease (COPD), 11% of asthma, 8% of injuries, 9% of lung cancer and 2% of leukemia, and about 100% of pneumoconioses and mesothelioma. These selected risks at work resulted in the loss of about 24 million years of healthy life and caused 850,000 deaths worldwide, about 40% of the ILO estimate of 2.2 million total deaths. CONCLUSIONS: These global and regional analyses have identified areas where specific preventive actions are required.

The global burden of selected occupational diseases and injury risks: Methodology and summary.

BACKGROUND: Around the globe, work has a heavy impact on health. To better advise policy makers, we assessed the global burden of disease and injury due to selected occupational hazards. This article presents an overview, and describes the methodology employed in the companion studies. METHODS: Using the World Health Organization (WHO) Comparative Risk Assessment methodology, we applied relative risk measures to the proportions of the population exposed to selected occupational hazards to estimate attributable fractions, deaths, and disability-adjusted life years (DALYs). Numerous occupational risk factors had to be excluded due to inadequate global data. RESULTS: In 2000, the selected risk factors were responsible worldwide for 37% of back pain, 16% of hearing loss, 13% of chronic obstructive pulmonary disease (COPD), 11% of asthma, 8% of injuries, 9% of lung cancer, and 2% of leukemia. These risks at work caused 850,000 deaths worldwide and resulted in the loss of about 24 million years of healthy life. Needlesticks accounted for about 40% of Hepatitis B and Hepatitis C infections and 4.4% of HIV infections in health care workers. CONCLUSIONS: Exposure to occupational hazards accounts for a significant proportion of the global burden of disease and injury, which could be substantially reduced through application of proven risk prevention strategies.

The global burden of non-malignant respiratory disease due to occupational airborne exposures.

BACKGROUND: Occupational non-malignant respiratory disease arises from exposure of workers to airborne agents, mostly particulate or dusts. We describe the worldwide mortality and morbidity from asthma, chronic obstructive pulmonary disease (COPD), and pneumoconioses arising from these occupational exposure and focus on cases reported in the year 2000. METHODS: The proportions of workers exposed to the agents, and their levels of exposure, were estimated using workforce data and the CAREX (CARcinogen EXposure) database. These were combined with relative risk measures (for asthma and COPD) or absolute risk measures (for the pneumoconioses) to develop estimates of deaths, disability-adjusted life years (DALYs) and attributable fraction (for asthma and COPD). RESULTS: There were an estimated 386,000 deaths (asthma: 38,000; COPD: 318,000; pneumoconioses: 30,000) and nearly 6.6 million DALYS (asthma: 1,621,000; COPD: 3,733,000, pneumoconioses: 1,288,000) due to exposure to occupational airborne particulates. CONCLUSIONS: Occupational airborne particulates are an important cause of death and disability worldwide.

The global burden of disease due to occupational carcinogens.

BACKGROUND: The worldwide mortality and morbidity from lung cancer, leukemia, and malignant mesothelioma arising from occupational exposures to carcinogens are described. Cases reported in the year 2000 that resulted from relevant past and current exposures are assessed. METHODS: The proportions of workers exposed to the carcinogens of interest, and their levels of exposure, were estimated using workforce data and the CAREX (CARcinogen EXposure) database. These were combined with relative risk measures (for lung cancer and leukemia) or absolute risk measures (for malignant mesothelioma) to develop estimates of deaths, disability-adjusted life years (DALYs) and attributable fraction (for lung cancer and leukemia). RESULTS: There were an estimated 152,000 deaths (lung cancer: 102,000; leukemia: 7,000; and malignant mesothelioma: 43,000) and nearly 1.6 million DALYS (lung cancer: 969,000; leukemia: 101,000; and malignant mesothelioma: 564,000) due to exposure to occupational carcinogens. CONCLUSIONS: Occupational carcinogens are an important cause of death and disability worldwide.

The global burden of occupational noise-induced hearing loss.

BACKGROUND: Excessive noise is a global occupational health hazard with considerable social and physiological impacts, including noise-induced hearing loss (NIHL). This paper describes the worldwide morbidity of occupational NIHL in the year 2000. METHODS: The proportion of the population exposed to occupational noise was estimated using noise exposure data from the US National Institute for Occupational Safety and Health (NIOSH), adjusted by data on the distribution of the work force by occupational category and economic sector, and economic activity rates in each WHO subregion. These values for the exposed population and risk measures for NIHL were used to develop estimates of the attributable fraction (AF) of adult-onset hearing loss resulting from occupational noise exposure. The AFs were applied to WHO estimates of total disability-adjusted life years (DALYs) from adult-onset hearing loss to estimate the DALYs due to occupational noise. RESULTS: Worldwide, 16% of the disabling hearing loss in adults (over 4 million DALYs) is attributed to occupational noise, ranging from 7% to 21% in the various subregions. The effects of the exposure to occupational noise are larger for males than females in all subregions and higher in the developing regions. CONCLUSIONS: Occupational noise is a significant cause of adult-onset hearing loss. The majority of this NIHL burden can be minimized by the use of engineering controls to reduce the generation of noise at its source.

Estimating the global burden of low back pain attributable to combined occupational exposures.

BACKGROUND: There is little information about the global burden of non-traumatic low back pain (LBP) attributable to the effects of physical and psychosocial occupational stressors. METHODS: Based on a review of the epidemiological evidence, occupation-specific relative risks were used to compute attributable proportions by age, gender, and geographical sub-region for the economically active population aged 15 and older. The reference group was professional/administrative workers; other risk categories were Low, clerical and sales; Moderate, operators (production workers) and service; and High, farmers. RESULTS: Worldwide, 37% of LBP was attributed to occupation, with twofold variation across regions. The attributable proportion was higher for men than women, because of higher participation in the labor force and in occupations with heavy lifting or whole-body vibration. Work-related LBP was estimated to cause 818,000 disability-adjusted life years lost annually. CONCLUSIONS: Occupational exposures to ergonomic stressors represent a substantial source of preventable back pain. Specific research on children is needed to quantify the global burden of disease due to child labor.

The global burden due to occupational injury.

BACKGROUND: Occupational injuries are a public health problem, estimated to kill more than 300,000 workers worldwide every year and to cause many more cases of disability. We estimate the global burden of fatal and non-fatal unintentional occupational injuries for the year 2000. METHODS: The economically active population (EAP) of about 2.9 billion workers was used as a surrogate of the population at risk for occupational injuries. Occupational unintentional injury fatality rates for insured workers, by country, were used to estimate WHO regional rates. These were applied to regional EAP to estimate the number of deaths. In addition to mortality, the disability-adjusted life years (DALYs) lost, which measure both morbidity and mortality, were calculated for 14 WHO regions. RESULTS: Worldwide, hazardous conditions in the workplace were responsible for a minimum of 312,000 fatal unintentional occupational injuries. Together, fatal and non-fatal occupational injuries resulted in about 10.5 million DALYs; that is, about 3.5 years of healthy life are lost per 1,000 workers every year globally. Occupational risk factors are responsible for 8.8% of the global burden of mortality due to unintentional injuries and 8.1% of DALYs due to this outcome. CONCLUSIONS: Occupational injuries constitute a substantial global burden. However, our findings greatly underestimate the impact of occupational risk factors leading to injuries in the overall burden of disease. Our estimates could not include intentional injuries at work, or commuting injuries, due to lack of global data. Additional factors contributing to grave underestimation of occupational injuries include limited insurance coverage of workers and substantial under-reporting of fatal injuries in record-keeping systems globally. About 113,000 deaths were probably missed in our analyses due to under-reporting alone. It is clear that known prevention strategies need to be implemented widely to diminish the avoidable burden of injuries in the workplace.

The cost effectiveness of occupational health interventions: prevention of silicosis.

BACKGROUND: The failure to recognize occupational health as an economic phenomenon limits the effectiveness of interventions ostensibly designed to prevent disease and injury. Hence, consideration of economic efficiency is essential in the evaluations of interventions to reduce hazardous working conditions. In this paper, we present an analysis of the cost effectiveness of alternative means of preventing silicosis. METHODS: To evaluate the cost effectiveness of specific interventions for the prevention of occupationally induced silicosis, we have used the simulation models based on the generalized cost-effectiveness analysis (GCEA) developed by the WHO-CHOICE initiative for two representative subregions namely AMROA (Canada, United States of America), and WPROB1 (China, Korea, Mongolia). RESULTS: In both of the two subregions, engineering controls are the most cost effective with ratios varying from 105.89 dollars per healthy year or disability adjusted life year saved in AMROA to approximately 109 dollars in WPROB1. In the two subregions, the incremental cost-effectiveness ratio of engineering controls (EC) looks most attractive. Although dust masks (DM) look attractive in terms of cost, the total efficacy is extremely limited. CONCLUSIONS: To the extent that this analysis can be generalized across other subregions, it suggests that engineering control programs would be cost effective in both developed and developing countries for reducing silica exposure to save lives. Note that this analysis understates health benefits since only silicosis and not all silica-related diseases are considered.