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.

Ethylene oxide and risk of lympho-hematopoietic cancer and breast cancer: a systematic literature review and meta-analysis.

PURPOSE: To conduct a systematic literature review and meta-analysis of studies of lympho-hematopoietic cancers (LHC) and breast cancer risk among persons occupationally exposed to ethylene oxide (EO). METHODS: We performed a literature search for articles available in PubMed and Web of Science databases to identify literature and subsequently systematically searched the reference lists of identified studies, published review papers and meta-analyses, as well as relevant government or regulatory documents. We qualitatively reviewed 30 studies and conducted meta-analyses on 13 studies. Pooled risk estimates were calculated using random effects models, stratifying by occupational group, cancer type and decade of publication. RESULTS: The overall meta-relative risks (meta-RRs) for LHC and breast cancer, respectively, were 1.48 (95% CI 1.07-2.05) and 0.97 (95% CI 0.80-1.18). The meta-RR's for LHC among EO production and EO sterilization workers were 1.46 (95% CI 0.85-2.50) and 1.07 (95% CI 0.87-1.30), respectively. We observed higher risks of LHC in the earlier published studies, compared to the later studies, and the meta-RR's for the 1980s, 1990s, 2000s, and the 2010s, respectively, were 3.87 (95% CI 1.87-8.01), 1.38 (95% CI 0.85-2.25), 1.05 (95% CI 0.84-1.31), and 1.19 (95% CI 0.80-1.77). CONCLUSIONS: The most informative epidemiology studies, which were published in the 2000s and 2010s, do not support the conclusion that exposure to EO is associated with an increased risk of LHC or breast cancer.

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. Annual age-adjusted incidence rates from 1973 to 2012 were obtained from the SEER 9, 13, and 18 databases for urban and rural locations, and standardized rate ratios were calculated. Female rural rates exceeded urban rates in almost half of the years analyzed, although the increases were not statistically significant, which is in line with expectations if there was no observable increased risk for urban locations. In contrast, male urban rates were elevated over rural rates for nearly all years examined and were statistically significantly elevated for 22 of the 40 years. Trend analyses demonstrated that trends for females remained relatively constant over time, whereas male urban and rural incidence increased into the 1980s and 1990s, followed by a decrease/leveling off. Annual female urban and rural incidence rates remained approximately five- to six-fold lower than male urban and rural incidence rates on average, consistent with the comparatively increased historical occupational asbestos exposure for males. The results suggest that differences in ambient asbestos concentrations, which have been reported to be 10-fold or greater across regions in the United States, have not influenced the risk of pleural mesothelioma.

Non-occupational exposure to asbestos and risk of pleural mesothelioma: review and meta-analysis.

OBJECTIVE: To conduct an updated literature review and meta-analysis of studies of pleural malignant mesothelioma (PMM) risk among persons exposed to asbestos non-occupationally (household and neighbourhood). METHODS: We performed a literature search for articles available in the National Center for Biotechnology Information's PubMed database published between 1967 and 2016. Meta-analyses were conducted to calculate pooled PMM risk estimates, stratifying for household or neighbourhood exposure to asbestos and/or predominant asbestos fibre type (chrysotile, amphibole or mixed). RESULTS: Eighteen studies in 12 countries comprising 665 cases met the meta-analysis inclusion criteria. We identified 13 estimates of PMM risk from neighbourhood exposures, 10 from household and one from mixed exposure, and combined the estimates using random-effects models. The overall meta-relative risk (meta-RR) was 5.9 (95% CI 4.4 to 8.7). The meta-RRs for household and neighbourhood exposures were 5.4 (95% CI 2.6 to 11.2) and 6.9 (95% CI 4.2 to 11.4), respectively. We observed trends in risk in relation to fibre type for both household and neighbourhood studies. For chrysotile, mixed and amphibole fibres, respectively, meta-RRs for neighbourhood studies were 3.8 (95% CI 0.4 to 38.4), 8.4 (95% CI 4.7 to 14.9) and 21.1 (95% CI 5.3 to 84.5) and meta-RRs for household studies were 4.0 (95% CI 0.8 to 18.8), 5.3 (95% CI 1.9 to 15.0) and 21.1 (95% CI 2.8 to 156.0). CONCLUSIONS: PMM risks from non-occupational asbestos exposure are consistent with the fibre-type potency response observed in occupational settings. By relating our findings to knowledge of exposure-response relationships in occupational settings, we can better evaluate PMM risks in communities with ambient asbestos exposures from industrial or other sources.

Slovakian glass fibre factory genotoxicity biomonitoring study - unsupported adverse outcome pathway (AOP) from the toxicology and human epidemiological experience of synthetic vitreous fibres (SVFs).

The article by Ceppi and colleagues, Genotoxic Effects of Occupational Exposure to, Glass Fibres - A Human Biomonitoring Study, published in Mutation Research -Genetic Toxicology and Environmental Mutagenesis in 2023 was reviewed with great interest. The authors undertook a novel approach to conducting a biomonitoring study of genotoxicity markers among a population of glass fibre manufacturing workers in Slovakia. On the surface, the Ceppi et al. (2023) study provides an interesting application of genotoxicity markers among a human population of workers to explore potential markers of effect (DNA strand breaks) and potential risk of susceptibility (e.g., genetic damage, disease, death). However, limited data for exposure reconstruction, uncertain influences from smoking history, and lack of consideration of decades of human epidemiology research showing no increased risk of malignant or non-malignant respiratory disease and mortality among glass fibre manufacturing workers, reveals that the conclusions of the authors are overreaching and inconsistent with the existing science. The limitations of this study preclude the ability to draw causal inferences or conclusions about DNA strand breaks as a marker of exposure, effect, or susceptibility within this population of Slovakian glass fibre workers. Further longitudinal research is required (e.g., more robust temporal assessment of occupational exposures - fibres and other compounds - and smoking history) to support the study conclusions.

The 2014 crude 4-methylcyclohexanemethanol chemical release and birth outcomes in West Virginia.

Approximately 10,000 gallons of crude 4-methylcyclohexanemethanol and propylene glycol phenyl ether were accidentally released into the Elk River upstream from a water treatment facility in West Virginia. The objective of this study was to use logistic and Poisson regression analyses to determine the effect potential exposures had on adverse birth outcomes (birth weight, small for gestational age, and abnormal Apgar score). We adjusted for confounding factors and assessed prevalence of adverse birth outcomes by residential location and timing of the pregnancy. There were no statistically significant interactions between residential location and timing of the pregnancy (range of p values: .157-.806). Changes in the prevalence of birth outcomes were consistent before and after the spill regardless of residential location. There was no evidence of an association between adverse birth outcomes and potential exposure to the released chemicals.

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.