Evaluation of airborne asbestos concentrations associated with the maintenance of brakes on an industrial overhead crane.

Objectives: To evaluate potential airborne asbestos exposures during brake maintenance and repair activities on a P&H overhead crane, and during subsequent handling of the mechanic's clothing.

Methods: Personal ( = 27) and area ( = 61) airborne fiber concentrations were measured during brake tests, removal, hand sanding, compressed air use, removal and reattachment of chrysotile-containing brake linings, and reinstallation of the brake linings. The mechanic's clothing was used to measure potential exposure during clothes handling.

Accuracy of professional judgments for dermal exposure assessment using deterministic models.

The accuracy of exposure judgments, particularly for scenarios where only qualitative information is available or a systematic approach is not used, has been evaluated and shown to have a relatively low level of accuracy. This is particularly true for dermal exposures, where less information is generally available compared to inhalation exposures. Relatively few quantitative validation efforts have been performed for scenarios where dermal exposures are of interest.

Comparison of Hydration Index, Percent Hydration, and Trans-Epidermal Water Loss Measurements for Dermal Exposure and Risk Assessment.

Skin hydration and the barrier properties of the stratum corneum have been reported to be influential factors in the potential for retention of solid and semi-solid substances on the skin surface. The measurement of these characteristics of the skin, however, remains relatively uncommon in exposure assessments performed by industrial or occupational hygienists, even when the focus of the assessment is exposure to the skin. This study provides measurements of skin hydration using multiple instruments and multiple relevant skin site locations for comparative analysis.

Evaluation of Airborne Asbestos Concentrations Associated with the Operation and Maintenance of Brakes and Clutches on Nonautomated Heavy Equipment.

This study evaluated the potential for chrysotile asbestos exposure during maintenance and operation of older, nonautomated heavy equipment with chrysotile-containing brake and clutch linings. Recent reports indicate that such equipment may be in current use in the U.S.

Potential Influence of Skin Hydration and Transepidermal Water Loss on the Dermal Transfer and Loading of Elemental Metallic Lead.

The factors influencing transfer of chemicals or other contaminants to and from the surface of the skin are often poorly understood. Previous research has indicated that environmental conditions, skin hydration, and repeated contacts may all influence the quantity of dermal transfer. The aim of this analysis was to evaluate the influence of skin hydration and condition on quantitative chemical transfer in a series of systematic measurements using human subjects for 5 and 10 repeated contacts.

Influence of repeated contacts on the transfer of elemental metallic lead between compartments in an integrated conceptual model for dermal exposure assessment.

Transfer of contaminants to and from the skin surface has been postulated to occur through a number of different pathways and compartments including: object(s)-to-skin, skin-to-skin, skin-to-clothing, skin-to-gloves, air-to-skin, skin-to-lips, and skin-to-saliva. However, many identified transfer pathways have been only minimally examined to determine the potential for measurable transfer. The purpose of this study was to quantitatively evaluate repeated transfer between different compartments using elemental metallic lead (Pb) in the solid form using a series of systematic measurements in human subjects.

Potential Airborne Asbestos Exposure and Risk Associated with the Historical Use of Cosmetic Talcum Powder Products.

Over time, concerns have been raised regarding the potential for human exposure and risk from asbestos in cosmetic-talc-containing consumer products. In 1985, the U.S.

Characterization of airborne BTEX exposures during use of lawnmowers and trimmers.

Few studies have evaluated airborne exposures to benzene, toluene, ethylbenzene, and xylenes (BTEX) during operation of two-stroke and four-stroke small engines, such as those in lawn maintenance equipment. Full-shift, 8-hour personal samples were collected during a simulation study to characterize yard maintenance activities including mowing, trimming, and fueling. Short-term, 15-minute personal samples were collected to separately evaluate mowing and trimming exposures.

Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence between Urban and Rural Areas in the United States (1973-2012).

Over the past 40 years, measured ambient asbestos concentrations in the United States have been higher in urban versus rural areas. The purpose of this study was to determine whether variations in ambient asbestos concentrations have influenced pleural mesothelioma risk in females (who generally lacked historic occupational asbestos exposure relative to males). Male pleural mesothelioma incidence trends were analyzed to provide perspective for female trends.

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.

Measured removal rates of chrysotile asbestos fibers from air and comparison with theoretical estimates based on gravitational settling and dilution ventilation.

Context: Industrial hygiene assessments often focus on activity-based airborne asbestos concentration measurements, but few empirical data exist regarding the fiber removal rate from air after activities cease.

Objective: Grade 7T chrysotile indoor fiber settling (FS) rates were characterized using air sampling (NIOSH Method 7402).

Materials And Methods: Six replicate events were conducted in a 58 m(3) study chamber (ventilation 3.

Analysis of workplace compliance measurements of asbestos by the U.S. Occupational Safety and Health Administration (1984-2011).

The United States Occupational Safety and Health Administration (OSHA) maintains the Chemical Exposure Health Data (CEHD) and the Integrated Management Information System (IMIS) databases, which contain quantitative and qualitative data resulting from compliance inspections conducted from 1984 to 2011. This analysis aimed to evaluate trends in workplace asbestos concentrations over time and across industries by combining the samples from these two databases. From 1984 to 2011, personal air samples ranged from 0.

Airborne asbestos take-home exposures during handling of chrysotile-contaminated clothing following simulated full shift workplace exposures.

The potential for para-occupational, domestic, or take-home exposures from asbestos-contaminated work clothing has been acknowledged for decades, but historically has not been quantitatively well characterized. A simulation study was performed to measure airborne chrysotile concentrations associated with laundering of contaminated clothing worn during a full shift work day. Work clothing fitted onto mannequins was exposed for 6.

Chemical assessment state of the science: Evaluation of 32 decision-support tools used to screen and prioritize chemicals.

The last decade has seen an increased focus on evaluating the safety and sustainability of chemicals in consumer and industrial products. In order to effectively and accurately evaluate safety and sustainability, tools are needed to characterize hazard, exposure, and risk pertaining to products and processes. Because many of these tools will be used to identify problematic chemistries, and because many have potential applications in various steps of an alternatives analysis, the limitations and capabilities of available tools should be understood by users so that, ultimately, potential chemical risk is accurately reflected.

Estimation of hand-to-mouth transfer efficiency of lead.

There are currently no published empirical data that characterize hand-to-mouth transfer efficiencies for metallic lead. The purpose of this study was to quantify the hand-to-mouth transfer efficiency of lead in adult volunteers (n = 6) using human saliva as a surrogate for the mouth and commercially available, 100% lead fishing weights as the source of lead for dermal loading. Study volunteers' saliva was collected and subsequently poured onto a sheet of wax paper placed on a balance scale.

Bayesian hierarchical framework for occupational hygiene decision making.

A hierarchical Bayesian framework has been developed for exposure assessment that makes use of statistical sampling-based techniques to estimate the posterior probability of the 95th percentile or arithmetic mean of the exposure distribution being located in one of several exposure categories. The framework can synthesize professional judgment and monitoring data to yield an updated posterior exposure assignment for routine exposure management. The framework is versatile enough that it can be modified for use in epidemiological studies for classifying the arithmetic mean instead of the 95th percentile into several exposure categories.

Evaluation of take-home exposure and risk associated with the handling of clothing contaminated with chrysotile asbestos.

The potential for para-occupational (or take-home) exposures from contaminated clothing has been recognized for the past 60 years. To better characterize the take-home asbestos exposure pathway, a study was performed to measure the relationship between airborne chrysotile concentrations in the workplace, the contamination of work clothing, and take-home exposures and risks. The study included air sampling during two activities: (1) contamination of work clothing by airborne chrysotile (i.

An analysis of workplace exposures to benzene over four decades at a petrochemical processing and manufacturing facility (1962-1999).

Benzene, a known carcinogen, can be generated as a by-product during the use of petroleum-based raw materials in chemical manufacturing. The aim of this study was to analyze a large data set of benzene air concentration measurements collected over nearly 40 years during routine employee exposure monitoring at a petrochemical manufacturing facility. The facility used ethane, propane, and natural gas as raw materials in the production of common commercial materials such as polyethylene, polypropylene, waxes, adhesives, alcohols, and aldehydes.

Analysis of finite dose dermal absorption data: implications for dermal exposure assessment.

A common dermal exposure assessment strategy estimates the systemic uptake of chemical in contact with skin using the fixed fractional absorption approach: the dermal absorbed dose is estimated as the product of exposure and the fraction of applied chemical that is absorbed, assumed constant for a given chemical. Despite the prominence of this approach there is little guidance regarding the evaluation of experiments from which fractional absorption data are measured. An analysis of these experiments is presented herein, and limitations to the fixed fractional absorption approach are discussed.

Analysis of BTEX groundwater concentrations from surface spills associated with hydraulic fracturing operations.

Unlabelled: Concerns have arisen among the public regarding the potentialfor drinking-water contamination from the migration of methane gas and hazardous chemicals associated with hydraulic fracturing and horizontal drilling. However, little attention has been paid to the potentialfor groundwater contamination resulting from surface spills from storage and production facilities at active well sites. We performed a search for publically available data regarding groundwater contamination from spills at ULS.

Airborne benzene exposures from cleaning metal surfaces with small volumes of petroleum solvents.

Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.