Historical evolution of regulatory standards for occupational and consumer exposures to industrial talc.

Talc has been used historically in a wide range of industrial applications and consumer products. The composition and purity of talc used for industrial purposes can vary greatly depending on the source and may contain asbestos minerals. The developing science associated with the health risks of asbestos had an effect on the talc industry throughout the 20th century. This review presents a detailed analysis of the evolution of regulatory standards impacting the use of industrial talc in the U.S. from the early 20th century through the 1990s. While it was recognized by the 1930s that airborne exposures to talc dust at high concentrations could cause lung disease, it was not until later that concerns were raised about the health risks associated with potential occupational exposures to asbestos from industrial talc. Regulatory agencies adopted occupational standards for industrial talc in the early 1970s, but the terminology used to define and characterize talc and other associated minerals varied between agencies. In addition, the complex and varying mineralogy of industrial talc led to inconsistent and imprecise interpretation of studies concerning health risk and occupational health standards among individual agencies.

History of knowledge and evolution of occupational health and regulatory aspects of asbestos exposure science: 1900-1975.

The understanding by industrial hygienists of the hazards of asbestos and appropriate ways to characterize and control exposure has evolved over the years. Here, a detailed analysis of the evolution of industrial hygiene practices regarding asbestos and its health risks, from the early 1900s until the advent of the national occupational health and safety regulatory structure currently in place in the US (early-to-mid 1970s) is presented. While industrial hygienists recognized in the early 1900s that chronic and high-level exposures to airborne concentrations of asbestos could pose a serious health hazard, it was not until the mid-1950s that the carcinogenic nature of asbestos began to be characterized and widespread concern followed. With the introduction of the membrane filter sampling method in the late 1960s and early 1970s, asbestos sampling and exposure assessment capabilities advanced to a degree which allowed industrial hygienists to more precisely characterize the exposure-response relationship. The ability of industrial hygienists, analytical chemists, toxicologists, and physicians to more accurately define this relationship was instrumental to the scientific community's ability to establish Occupational Exposure Levels (OELs) for asbestos. These early developments set the stage for decades of additional study on asbestos exposure potential and risk of disease. This was followed by the application of engineering controls and improved respiratory protection which, over the years, saved thousands of lives. This paper represents a state-of-the-art review of the knowledge of asbestos within the industrial hygiene community from about 1900 to 1975.

Airborne asbestos exposures associated with the installation and removal of roofing products.

Asbestos-containing roofing products were widely used throughout the 20th century, and certain products are still used in limited quantities today. Roofing products are generally considered non-friable and are not expected to release appreciable amounts of airborne asbestos fibers; however, despite the variety of roofing products that have contained asbestos over time, there are no comprehensive analyses of the exposure data associated with these products in the published literature. The objective of this study was to analyze the available data and characterize asbestos exposures associated with the installation, removal, and replacement of built-up roofing (BUR), felts, flashings, shingles, coatings, cements, and mastics under a variety of work practices. Published and unpublished literature that contained the following information was included in the analysis: (1) airborne fiber concentrations determined by PCM; (2) a description of the product(s) used; and (3) a description of the task(s) performed. More than 800 personal air samples from 12 studies performed between 1982 and 2010 were identified which fit the inclusion criteria. The findings indicate that short-term and full-shift exposures from the use of asbestos-containing roofing products were typically well below applicable occupational exposure limits. Additionally, the cumulative exposures associated with roofing work would be well below published chrysotile no-observed-adverse-effect-levels (NOAELs) for asbestos-related diseases.

Naturally occurring diacetyl and 2,3-pentanedione concentrations associated with roasting and grinding unflavored coffee beans in a commercial setting.

Over the last decade, concerns have been raised about potential respiratory health effects associated with occupational exposure to the flavoring additives diacetyl and 2,3-pentanedione. Both of these diketones are also natural components of many foods and beverages, including roasted coffee. To date, there are no published studies characterizing workplace exposures to these diketones during commercial roasting and grinding of unflavored coffee beans. In this study, we measured naturally occurring diacetyl, 2,3-pentanedione, and respirable dust at a facility that roasts and grinds coffee beans with no added flavoring agents. Sampling was conducted over the course of three roasting batches and three grinding batches at varying distances from a commercial roaster and grinder. The three batches consisted of lightly roasted soft beans, lightly roasted hard beans, and dark roasted hard beans. Roasting occurred for 37 to 41 min, and the grinding process took between 8 and 11 min. Diacetyl, 2,3-pentanedione, and respirable dust concentrations measured during roasting ranged from less than the limit of detection (

Airborne asbestos exposures associated with gasket and packing replacement: a simulation study of flange and valve repair work and an assessment of exposure variables.

A simulation study was conducted to evaluate worker and area exposure to airborne asbestos associated with the replacement of asbestos-containing gaskets and packing materials from flanges and valves and assess the influence of several variables previously not investigated. Additionally, potential of take home exposures from clothing worn during the study was characterized. Our data showed that product type, ventilation type, gasket location, flange or bonnet size, number of flanges involved, surface characteristics, gasket surface adherence, and even activity type did not have a significant effect on worker exposures. Average worker asbestos exposures during flange gasket work (PCME=0.166 f/cc, 12-59 min) were similar to average worker asbestos exposures during valve overhaul work (PCME=0.165 f/cc, 7-76 min). Average 8-h TWA asbestos exposures were estimated to range from 0.010 to 0.062 f/cc. Handling clothes worn during gasket and packing replacement activities demonstrated exposures that were 0.71% (0.0009 f/cc 40-h TWA) of the airborne asbestos concentration experienced during the 5 days of the study. Despite the many variables considered in this study, exposures during gasket and packing replacement occur within a relatively narrow range, are below current and historical occupational exposure limits for asbestos, and are consistent with previously published data.

State-of-the-science review of the occupational health hazards of crystalline silica in abrasive blasting operations and related requirements for respiratory protection.

Excessive exposures to airborne crystalline silica have been known for over 100 years to pose a serious health hazard. Work practices and regulatory standards advanced as the knowledge of the hazards of crystalline silica evolved. This article presents a comprehensive historical examination of the literature on exposure, health effects, and personal protective equipment related to silica and abrasive blasting operations over the last century. In the early 1900s, increased death rates and prevalence of pulmonary disease were observed in industries that involved dusty operations. Studies of these occupational cohorts served as the basis for the first occupational exposure limits in the 1930s. Early exposure studies in foundries revealed that abrasive blasting operations were particularly hazardous and provided the basis for many of the engineering control and respiratory protection requirements that are still in place today. Studies involving abrasive blasters over the years revealed that engineering controls were often not completely effective at reducing airborne silica concentrations to a safe level; consequently, respiratory protection has always been an important component of protecting workers. During the last 15-20 yr, quantitative exposure-response modeling, experimental animal studies, and in vitro methods were used to better understand the relationship between exposure to silica and disease in the workplace. In light of Occupational Safety and Health Administration efforts to reexamine the protectiveness of the current permissible exposure limit (PEL) for crystalline silica and its focus on protecting workers who are known to still be exposed to silica in the workplace (including abrasive blasters), this state-of-the-science review of one of the most hazardous operations involving crystalline silica should provide useful background to employers, researchers, and regulators interested in the historical evolution of the recognized occupational health hazards of crystalline silica and abrasive blasting operations and the related requirements for respiratory protection.

2006 Henry f. Smyth jr. Award lecture historical review--employer responsibility for workplace health and safety.

The Academy of Industrial Hygiene established the Henry F. Smyth Jr. Award in 1981. The Award is presented to that individual who has recognized the needs of the industrial hygiene profession and has made major contributions to fulfill those needs, thereby contributing to the improvement of the public welfare. This year's Award was presented to John L. Henshaw, CIH, at the 2006 Professional Conference on Industrial Hygiene (PCIH) in San Jose, California.