An updated evaluation of reported no-observed adverse effect levels for chrysotile, amosite, and crocidolite asbestos for lung cancer and mesothelioma.

This analysis updates two previous analyses that evaluated the exposure-response relationships for lung cancer and mesothelioma in chrysotile-exposed cohorts. We reviewed recently published studies, as well as updated information from previous studies. Based on the 16 studies considered for chrysotile (<10% amphibole), we identified the "no-observed adverse effect level" (NOAEL) for lung cancer and/or mesothelioma; it should be noted that smoking or previous or concurrent occupational exposure to amphiboles (if it existed) was not controlled for. NOAEL values ranged from 2.3-<11.5 f/cc-years to 1600-3200 f/cc-years for lung cancer and from 100-<400 f/cc-years to 800-1599 f/cc-years for mesothelioma. The range of best-estimate NOAELs was estimated to be 97-175 f/cc-years for lung cancer and 250-379 f/cc-years for mesothelioma. None of the six cohorts of cement or friction product manufacturing workers exhibited an increased risk at any exposure level, while all but one of the six studies of textile workers reported an increased risk at one or more exposure levels. This is likely because friction and cement workers were exposed to much shorter chrysotile fibers. Only eight cases of peritoneal mesothelioma were reported in all studies on predominantly chrysotile-exposed cohorts combined. This analysis also proposed best-estimate amosite and crocidolite NOAELs for mesothelioma derived by the application of relative potency estimates to the best-estimate chrysotile NOAELs for mesothelioma and validated by epidemiology studies with exposure-response information. The best-estimate amosite and crocidolite NOAELs for mesothelioma were 2-5 f/cc-years and 0.6-1 f/cc-years, respectively. The rate of peritoneal mesothelioma in amosite- and crocidolite-exposed cohorts was between approximately 70- to 100-fold and several-hundred-fold higher than in chrysotile-exposed cohorts, respectively. These findings will help characterize potential worker and consumer health risks associated with historical and current chrysotile, amosite, and crocidolite exposures.

Occupational exposure to cosmetic talc and mesothelioma in barbers, hairdressers, and cosmetologists: A systematic review of the epidemiology.

Inhalation exposure to cosmetic talc has generated much scientific debate regarding its potential as a risk factor for mesothelioma, a rare, but fatal cancer. Barbers, hairdressers, and cosmetologists have regularly used cosmetic talc-containing products, but the collective epidemiological evidence for mesothelioma in these occupations has yet to be described. As such, we conducted a systematic review of PubMed and the National Institute for Occupational Safety and Health's (NIOSH) Numbered Publications list to identify original epidemiological literature reporting measures of association between these occupations and incidence of or death from mesothelioma. Literature screening was performed independently twice, the results of which were summarized and tabulated and underwent a review for their accuracy. A total of 12 studies met our inclusion criteria, including three cohort, six case-control, and three proportionate mortality/registration studies. The data from these studies were collected in 13 European and North American countries, spanning more than 50 years. We supplemented this review with queries of occupational mortality databases that are managed by the Washington State Department of Health and NIOSH for 26 U.S. states. Most findings were null and if statistically significant, nearly all showed an inverse relationship, indicative of a protective effect of these occupations on mesothelioma risk. Overall, the epidemiological evidence does not support an increased risk of mesothelioma for these occupations. This research fills an important data gap on the etiology of mesothelioma in barbers, hairdressers, and cosmetologists, and provides a benchmark for those with comparatively less exposure, such as non-occupational users of similar cosmetic talc-containing products.

Evaluation of asbestos exposure resulting from simulated application of spiked talcum powders.

This study characterizes airborne asbestos exposures resulting from the adult application of cosmetic talc body powders spiked with known concentrations of tremolite. Raw talc ores were spiked with 0.005% and 0.1% asbestiform or non-asbestiform tremolite. Personal samples were collected during 16 simulated events, including puff and shaker application and associated clean-up activities. Airborne fiber levels (PCM) were not significantly different for simulations involving talc spiked with asbestiform and non-asbestiform tremolite (p = 0.6104). For application and clean-up of talc spiked with 0.005% asbestiform tremolite, 2 of 24 (8.3%) samples were above the LOD for TEM (0.003 f/cc). For application of talc spiked with 0.1% asbestiform tremolite, 21 of 24 (87.5%) were above the LOD for TEM. The corresponding mean PCME asbestos concentrations were 0.016 f/cc for puff and shaker for samples collected in the first 15 min, 0.002 f/cc for puff and 0.004 f/cc for shaker in the second 15 min, and 0.005 f/cc for puff and 0.013 f/cc for shaker for the full 30 min. Mean PCME concentrations for samples collected during clean-up following application of talc spiked with 0.1% asbestiform tremolite were 0.003 f/cc for samples collected in the first 15 min following puff application, 0.005 f/cc for samples collected in the second 15 min following shaker application, and 0 f/cc for the remaining clean-up samples. Using the EPA's exposure factors, we determined the range of cumulative asbestiform fiber exposures that would result from product use, assuming asbestiform tremolite was present at 0.1%.

Pilot study evaluating inhalation and dermal glyphosate exposure resulting from simulated heavy residential consumer application of Roundup®.

OBJECTIVES: The purpose of this study was to evaluate the individual contributions of inhalation and dermal exposures to urinary glyphosate levels following the heavy residential consumer application of a glyphosate-containing herbicide. METHODS: A pilot study was conducted in which each participant mixed and continuously spray-applied 16.3 gallons of a 0.96% glyphosate-containing solution for 100 min using a backpack sprayer. Twelve participants were divided evenly into two exposure groups, one equipped to assess dermal exposure and the other, inhalation exposure. Personal air samples (n = 12) and dermal patch samples (n = 24) were collected on the inhalation group participants and analyzed for glyphosate using HPLC-UV. Serial urine samples collected 30-min prior to application and 3-, 6-, 12-, 24-hr (inhalation and dermal groups) and 36-hr (dermal group only) post-application were analyzed for glyphosate and glyphosate's primary metabolite (AMPA) using HPLC-MS/MS. RESULTS: The mean airborne glyphosate concentration was 0.0047 mg/m3, and the mean concentrations of glyphosate for each applicator's four patch samples ranged from 0.04 µg/mm2 to 0.25 µg/mm2. In general, urinary glyphosate, AMPA, and total effective glyphosate levels were higher in the dermal exposure group than the inhalation exposure group, peaked within 6-hr following application, and were statistically indistinguishable from background at 24-hr post-application. CONCLUSIONS: This is the first study to characterize the absorption and biological fate of glyphosate in residential consumer applicators following heavy application. The results of this pilot study are consistent with previous studies that have shown that glyphosate is rapidly eliminated from the body, typically within 24 hr following application.

Evaluation of the presence of asbestos in cosmetic talcum products.

Talc has been used for over a century in a variety of cosmetic products. While pure cosmetic talc (free of asbestos) is not considered a risk factor for mesothelioma, it has been recently suggested that inhalation of cosmetic talc containing trace levels of asbestos is a risk factor for mesothelioma. Bulk analyses of cosmetic talcum products were performed in the 1960s and 1970s, however, the analytical methods used at that time were incapable of determining whether asbestos minerals were present in the asbestiform versus non-asbestiform habit. The distinction between these two mineral habits is critical, as non-asbestiform amphibole minerals do not present an asbestos-related cancer risk via inhalation. As such, we evaluated six historical talcum powders using modern-era analytical methods to determine if asbestos is present, and if so, to identify the mineral habit (asbestiform versus non-asbestiform) of the asbestos. Based on their labels, the products were produced by four manufacturers and sold between 1940 and 1977. The products were analyzed in duplicate by two laboratories using standard protocols. Laboratory A analyzed samples using X-ray diffraction (XRD) and polarized light microscopy (PLM), and Laboratory B analyzed samples using PLM and transmission electron microscopy (TEM) with energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED). No asbestiform minerals were found in any of the products. Nonetheless, even if some historical cosmetic talcum products contained trace amounts (≤0.1%) of asbestiform minerals, any resulting asbestos exposure would be expected to be exceedingly low, and comparable to exposures from breathing ambient air.

Evaluation of take-home exposure to asbestos from handling asbestos-contaminated worker clothing following the abrasive sawing of cement pipe.

Although industrial uses of asbestos have declined since the 1970s, in recent years there has been a renewed interest in para-occupational ("take-home") exposure to these fibers. The aim of this study was to quantify the release of asbestos fibers, if any, during the shaking out of crocidolite- and chrysotile-contaminated clothing in a simulated at-home setting. An exposure study was conducted in which personal and area air samples were collected during the handling (i.e. shake-out) of work clothing (shirt and pants) previously worn by an operator who had cut asbestos-containing cement pipe. During eight "loading" events, the operator cut a historically representative asbestos-containing cement pipe (10% crocidolite and 25% chrysotile) using a powered abrasive saw. Subsequently, 30-minute air samples were collected during four "shake-out" events, each of which consisted of the handling of two complete sets of contaminated work clothes. Samples were analyzed in accordance with NIOSH methods 7400 and 7402. The mean phase contrast microscopy equivalent (PCME) airborne concentrations were 0.52 f/cc (SD = 0.34 f/cc) for total asbestos fibers, 0.36 f/cc (SD = 0.26 f/cc) for chrysotile and 0.17 f/cc (SD = 0.096 f/cc) for crocidolite. Based on likely estimates of the frequency of laundering activities, and assuming that the dusty clothing (1) is not blown off in the occupational setting using compressed air and (2) is not shaken out before entering the home, a family member handling the clothing could potentially have a lifetime cumulative exposure to chrysotile and crocidolite of approximately 0.20 f/cc-year and 0.096 f/cc-year, respectively.

An assessment of formaldehyde emissions from laminate flooring manufactured in China.

Formaldehyde emissions from two laminate flooring products, labeled as California Air Resources Board (CARB) compliant, were evaluated. Passive 24-hr samples (n = 79) and real-time measurements were collected following installation and removal of the products in two rooms of similar size. Mean formaldehyde concentrations following installation were 0.038 and 0.022 ppm for Products 1 and 2 respectively, and 7 days after flooring removal the concentrations returned to background pre-installation levels. Both products were also evaluated in a small chamber (ASTM D6007) using Deconstructive (de-laminated product) and Non-Deconstructive (intact product) methods. Deconstructive testing showed that Product 1 exceeded the applicable CARB emission standard by 4-fold, while Product 2 was equivalent to the standard. Non-Deconstructive measurements were far below the Deconstructive results and were used to predict 24-hr steady-state room air concentrations. Based on the products that we tested (one of which was found to not be compliant with the CARB standard), the airborne formaldehyde concentrations measured following installation in a real-world setting would not be expected to elicit adverse acute health effects.

An updated evaluation of reported no-observed adverse effect levels for chrysotile asbestos for lung cancer and mesothelioma.

Although consumption of chrysotile asbestos has decreased since the 1970s, the latency period of asbestos-related cancers is thought to be at least 20-30 years, and therefore the potential health risks associated with historical exposures is still actively researched. This analysis represents an update to a previous paper in which we evaluated the exposure-response relationships for lung cancer and mesothelioma in chrysotile-exposed cohorts. Here, we review several recently published studies as well as updated information from previous studies. For each of the 14 studies considered, we identified the "no-observed adverse effect level" (NOAEL) for lung cancer and/or mesothelioma. NOAEL values for lung cancer ranged from 1.1 to <20 f/cc-years to 1600-3200 f/cc-years, and for mesothelioma ranged from 100-400 f/cc-years to 800-1599 f/cc-years. The range of "best estimate" NOAELs was estimated to be 89-168 f/cc-years for lung cancer and 208-415 f/cc-years for mesothelioma. None of the six cohorts of cement or friction product manufacturing workers exhibited an increased lung cancer risk at any exposure level, while all of the five studies of textile workers reported an increased risk at one or more exposure levels. This is likely because friction and cement workers were exposed to much shorter chrysotile fibers. Of the seven cases of peritoneal mesothelioma reported in the included studies, none were observed in the analyses of cement or friction product manufacturing workers in the absence of crocidolite exposure. These findings will help characterize potential worker and consumer health risks associated with historical and current chrysotile exposures.

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.

Historical ambient airborne asbestos concentrations in the United States - an analysis of published and unpublished literature (1960s-2000s).

Outdoor concentrations of airborne asbestos have been measured throughout the US over time. However, a thorough review and analysis of these data has not been conducted. The purpose of this study is to characterize asbestos concentrations in ambient air by environment type (urban, rural) and by decade, using measurements collected in the absence of known asbestos emission sources. A total of 17 published and unpublished studies and datasets were identified that reported the results of 2058 samples collected from the 1960s through the 2000s across the US. Most studies did not report asbestos fiber type, and data based on different analytical methods (e.g. Phase Contrast Microscopy, Transmission Electron Microscopy, etc.) were combined in the dataset; however, only fibers ≥5 µm in length were considered. For a small subset of the measurements (n = 186, 9.0%), a conversion factor was used to convert mass-based data (e.g. ng/m(3)) to count-based values (i.e. f/cc ≥5 µm). The estimated overall mean and median ambient asbestos concentrations for the 1960s through 2000s were 0.00093 f/cc and 0.00022 f/cc, respectively. Concentrations generally increased from the 1960s through the early 1980s, after which they declined considerably. While asbestos use decreased throughout the 1970s, these results indicate that ambient concentrations peaked during the early 1980s, which suggests the possible contribution of abatement or demolition activities. Lastly, ambient asbestos concentrations were higher in urban than rural settings, which is consistent with the greater use of asbestos-containing materials in more densely populated areas.

Effects of the NFL's Amendments to the Free Kick Rule on Injuries during the 2010 and 2011 Seasons.

Recognizing the chronic health effects associated with playing football, the National Football League (NFL) has enacted policies and rules aimed at improving player health and safety. Prior to the 2011 season, amendments to the Free Kick rule were implemented, whereby the restraining line was moved from the 30- to the 35-yard line and all kicking team players other than the kicker were required to line up no more than 5 yards behind their restraining line. The objective of this analysis was to evaluate the effects of these rule changes on injury rates. Data for injuries occurring on special teams plays during the 2010 and 2011 NFL seasons were obtained from publically available NFL gamebooks and injury reports. Injury rates for kickoff plays across seasons were statistically compared using incidence rate ratios (RR) and 95% confidence intervals. To evaluate whether injury rate changes could be attributable to the rule amendments, comparisons were made with punt injury rates (presumably unaffected by the Free Kick rule changes) and distributions of potential confounders were assessed across seasons. Incidence of injuries occurring on kickoff plays fell from 2010 to 2011 (RR: 0.45, 95% CI: 0.28-0.73), although on kickoff plays where the ball was returned, this decrease became non-significant (RR: 0.67, 95% CI: 0.41-1.08). While the incidence of head injuries decreased by approximately 3-fold during kickoff plays, this change was not statistically significant (RR: 0.33, 95% CI: 0.09-1.21). No difference was observed in injury incidence during punts between the two seasons, and the distribution of confounding factors was largely uniform across seasons. The observed decrease in injuries occurring during kickoffs was likely directly attributable to the Free Kick rule amendments, principally from the increased frequency of touchbacks. The absence of a significant change in head injuries during kickoffs was unexpected, but may be attributable to small sample size. Despite the injury rate reductions, the rule changes likely had little effect on player safety during active gameplay.

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 (

Characterization of naturally occurring airborne diacetyl concentrations associated with the preparation and consumption of unflavored coffee.

Diacetyl, a suspected cause of respiratory disorders in some food and flavorings manufacturing workers, is also a natural component of roasted coffee. We characterized diacetyl exposures that would plausibly occur in a small coffee shop during the preparation and consumption of unflavored coffee. Personal (long- and short-term) and area (long-term) samples were collected while a barista ground whole coffee beans, and brewed and poured coffee into cups. Simultaneously, long-term personal samples were collected as two participants, the customers, drank one cup of coffee each per h. Air sampling and analyses were conducted in accordance with OSHA Method 1012. Diacetyl was detected in all long-term samples. The long-term concentrations for the barista and area samples were similar, and ranged from 0.013â¿¿0.016 ppm; long-term concentrations for the customers were slightly lower and ranged from 0.010â¿¿0.014 ppm. Short-term concentrations ranged from below the limit of detection (<0.0047 ppm)â¿¿0.016 ppm. Mean estimated 8 h time-weighted average (8 h TWA) exposures for the barista ranged from 0.007â¿¿0.013 ppm; these values exceed recommended 8 h TWA occupational exposure limits (OELs) for diacetyl and are comparable to long-term personal measurements collected in various food and beverage production facilities. The concentrations measured based on area sampling were comparable to those measured in the breathing zone of the barista, thus exceedances of the recommended OELs may also occur for coffee shop workers who do not personally prepare coffee (e.g., cashier, sanitation/maintenance). These findings suggest that the practicality and scientific basis of the recommended OELs for diacetyl merit further consideration.

Diacetyl and 2,3-pentanedione exposures associated with cigarette smoking: implications for risk assessment of food and flavoring workers.

Diacetyl and 2,3-pentanedione inhalation have been suggested as causes of severe respiratory disease, including bronchiolitis obliterans, in food/flavoring manufacturing workers. Both compounds are present in many food items, tobacco, and other consumer products, but estimates of exposures associated with the use of these goods are scant. A study was conducted to characterize exposures to diacetyl and 2,3-pentanedione associated with cigarette smoking. The yields (µg/cigarette) of diacetyl and 2,3-pentanedione in mainstream (MS) cigarette smoke were evaluated for six tobacco products under three smoking regimens (ISO, Massachusetts Department of Public Health, and Health Canada Intense) using a standard smoking machine. Mean diacetyl concentrations in MS smoke ranged from 250 to 361 ppm for all tobacco products and smoking regimens, and mean cumulative exposures associated with 1 pack-year ranged from 1.1 to 1.9 ppm-years. Mean 2,3-pentanedione concentrations in MS smoke ranged from 32.2 to 50.1 ppm, and mean cumulative exposures associated with 1 pack-year ranged from 0.14 to 0.26 ppm-years. We found that diacetyl and 2,3-pentanedione exposures from cigarette smoking far exceed occupational exposures for most food/flavoring workers who smoke. This suggests that previous claims of a significant exposure-response relationship between diacetyl inhalation and respiratory disease in food/flavoring workers were confounded, because none of the investigations considered or quantified the non-occupational diacetyl exposure from cigarette smoke, yet all of the cohorts evaluated had considerable smoking histories. Further, because smoking has not been shown to be a risk factor for bronchiolitis obliterans, our findings are inconsistent with claims that diacetyl and/or 2,3-pentanedione exposure are risk factors for this disease.

Long-term health experience of jet engine manufacturing workers: VIII. glioblastoma incidence in relation to workplace experiences with parts and processes.

OBJECTIVE: To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with workplace experiences with specific parts produced and processes performed. METHODS: Subjects were 210,784 workers employed between 1952 and 2001. We conducted nested case-control and cohort incidence studies with focus on 277 GB cases. We estimated time experienced with 16 part families, 4 process categories, and 32 concurrent part-process combinations with 20 or more GB cases. RESULTS: In both the cohort and case-control studies, none of the part families, process categories, or both considered was associated with increased GB risk. CONCLUSIONS: If not due to chance alone, the not statistically significantly elevated GB rates in the North Haven plant may reflect external occupational factors or nonoccupational factors unmeasured in the current evaluation.

Malignant pleural mesothelioma in US automotive mechanics: reported vs expected number of cases from 1975 to 2007.

Until the 1980s, chrysotile asbestos was a component of automotive brakes manufactured in the US. The current OSHA Bulletin (2006) for brake repair cites a single study (Lemen, 2004) which concluded that the number of mesothelioma cases reported in the literature in "end-product users of friction materials" indicated an asbestos-related risk for auto mechanics. However, Lemen (2004) did not compare the reported number of cases to an "expected" value, even though pleural mesothelioma occurs in the general population in the absence of asbestos exposure. We compare the number of malignant pleural mesothelioma (MPM) cases reported in the US literature among auto mechanics between 1975-2007 to an expected value derived from estimated numbers of current and former auto mechanics. A total of 106 cases categorized as mesothelioma or malignant neoplasm of the pleura were found in the literature. Using background incidence rates for MPM of two and three cases per million individuals per year, we estimated that a range of 278-515 cases of non-asbestos-related MPM, respectively, would have occurred in current or former auto mechanics from 1975-2007. Our findings are consistent with the numerous epidemiology studies that have found no increased risk of MPM in auto mechanics.

Evaluation of tremolite asbestos exposures associated with the use of commercial products.

Tremolite is a noncommercial form of amphibole mineral that is present in some chrysotile, talc, and vermiculite deposits. Inhalation of asbestiform tremolite is suspected to have caused or contributed to an increased incidence of mesothelioma in certain mining settings; however, very little is known about the magnitude of tremolite exposure that occurred at these locations, and even less is known regarding tremolite exposures that might have occurred during consumer use of chrysotile, talc, and vermiculite containing products. The purpose of this analysis is to evaluate the exposure-response relationship for tremolite asbestos and mesothelioma in high exposure settings (mining) and to develop estimates of tremolite asbestos exposure for various product use scenarios. Our interpretation of the tremolite asbestos exposure metrics reported for the Thetford chrysotile mines and the Libby vermiculite deposits suggests a lowest-observed-adverse-effect level (LOAEL) for mesothelioma of 35-73 f/cc-year. Using measured and estimated airborne tremolite asbestos concentrations for simulated and actual product use, we conservatively estimated the following cumulative tremolite asbestos exposures: career auto mechanic: 0.028 f/cc-year; non-occupational use of joint compound: 0.0006 f/cc-year; non-occupational use of vermiculite-containing gardening products: 0.034 f/cc-year; home-owner removal of Zonolite insulation: 0.0002 f/cc-year. While the estimated consumer tremolite exposures are far below the tremolite LOAELs derived herein, this analysis examines only a few of the hundreds of chrysotile- and talc-containing products.