1
|
Thompson JA, Kashon ML, McKinney W, Fedan JS. High-fat Western diet alters crystalline silica-induced airway epithelium ion transport but not airway smooth muscle reactivity. BMC Res Notes 2024; 17:13. [PMID: 38172968 PMCID: PMC10765734 DOI: 10.1186/s13104-023-06672-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024] Open
Abstract
OBJECTIVES Silicosis is an irreversible occupational lung disease resulting from crystalline silica inhalation. Previously, we discovered that Western diet (HFWD)-consumption increases susceptibility to silica-induced pulmonary inflammation and fibrosis. This study investigated the potential of HFWD to alter silica-induced effects on airway epithelial ion transport and smooth muscle reactivity. METHODS Six-week-old male F344 rats were fed a HFWD or standard rat chow (STD) and exposed to silica (Min-U-Sil 5®, 15 mg/m3, 6 h/day, 5 days/week, for 39 d) or filtered air. Experimental endpoints were measured at 0, 4, and 8 weeks post-exposure. Transepithelial potential difference (Vt), short-circuit current (ISC) and transepithelial resistance (Rt) were measured in tracheal segments and ion transport inhibitors [amiloride, Na+ channel blocker; NPPB; Cl- channel blocker; ouabain, Na+, K+-pump blocker] identified changes in ion transport pathways. Changes in airway smooth muscle reactivity to methacholine (MCh) were investigated in the isolated perfused trachea preparation. RESULTS Silica reduced basal ISC at 4 weeks and HFWD reduced the ISC response to amiloride at 0 week compared to air control. HFWD + silica exposure induced changes in ion transport 0 and 4 weeks after treatment compared to silica or HFWD treatments alone. No effects on airway smooth muscle reactivity to MCh were observed.
Collapse
Affiliation(s)
- Janet A Thompson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505, USA.
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, 1000 Frederick Lane, Morgantown, WV, 26508, USA.
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505, USA
| | - Walter McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505, USA
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505, USA
| |
Collapse
|
2
|
Favor OK, Pestka JJ, Bates MA, Lee KSS. Centrality of Myeloid-Lineage Phagocytes in Particle-Triggered Inflammation and Autoimmunity. FRONTIERS IN TOXICOLOGY 2021; 3:777768. [PMID: 35295146 PMCID: PMC8915915 DOI: 10.3389/ftox.2021.777768] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/19/2021] [Indexed: 12/14/2022] Open
Abstract
Exposure to exogenous particles found as airborne contaminants or endogenous particles that form by crystallization of certain nutrients can activate inflammatory pathways and potentially accelerate autoimmunity onset and progression in genetically predisposed individuals. The first line of innate immunological defense against particles are myeloid-lineage phagocytes, namely macrophages and neutrophils, which recognize/internalize the particles, release inflammatory mediators, undergo programmed/unprogrammed death, and recruit/activate other leukocytes to clear the particles and resolve inflammation. However, immunogenic cell death and release of damage-associated molecules, collectively referred to as "danger signals," coupled with failure to efficiently clear dead/dying cells, can elicit unresolved inflammation, accumulation of self-antigens, and adaptive leukocyte recruitment/activation. Collectively, these events can promote loss of immunological self-tolerance and onset/progression of autoimmunity. This review discusses critical molecular mechanisms by which exogenous particles (i.e., silica, asbestos, carbon nanotubes, titanium dioxide, aluminum-containing salts) and endogenous particles (i.e., monosodium urate, cholesterol crystals, calcium-containing salts) may promote unresolved inflammation and autoimmunity by inducing toxic responses in myeloid-lineage phagocytes with emphases on inflammasome activation and necrotic and programmed cell death pathways. A prototypical example is occupational exposure to respirable crystalline silica, which is etiologically linked to systemic lupus erythematosus (SLE) and other human autoimmune diseases. Importantly, airway instillation of SLE-prone mice with crystalline silica elicits severe pulmonary pathology involving accumulation of particle-laden alveolar macrophages, dying and dead cells, nuclear and cytoplasmic debris, and neutrophilic inflammation that drive cytokine, chemokine, and interferon-regulated gene expression. Silica-induced immunogenic cell death and danger signal release triggers accumulation of T and B cells, along with IgG-secreting plasma cells, indicative of ectopic lymphoid tissue neogenesis, and broad-spectrum autoantibody production in the lung. These events drive early autoimmunity onset and accelerate end-stage autoimmune glomerulonephritis. Intriguingly, dietary supplementation with ω-3 fatty acids have been demonstrated to be an intervention against silica-triggered murine autoimmunity. Taken together, further insight into how particles drive immunogenic cell death and danger signaling in myeloid-lineage phagocytes and how these responses are influenced by the genome will be essential for identification of novel interventions for preventing and treating inflammatory and autoimmune diseases associated with these agents.
Collapse
Affiliation(s)
- Olivia K. Favor
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
| | - James J. Pestka
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, United States
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Melissa A. Bates
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, United States
| | - Kin Sing Stephen Lee
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
- Department of Chemistry, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
3
|
Rozhina E, Ishmukhametov I, Nigamatzyanova L, Akhatova F, Batasheva S, Taskaev S, Montes C, Lvov Y, Fakhrullin R. Comparative Toxicity of Fly Ash: An In Vitro Study. Molecules 2021; 26:molecules26071926. [PMID: 33808134 PMCID: PMC8038091 DOI: 10.3390/molecules26071926] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 01/25/2023] Open
Abstract
Fly ash produced during coal combustion is one of the major sources of air and water pollution, but the data on the impact of micrometer-size fly ash particles on human cells is still incomplete. Fly ash samples were collected from several electric power stations in the United States (Rockdale, TX; Dolet Hill, Mansfield, LA; Rockport, IN; Muskogee, OK) and from a metallurgic plant located in the Russian Federation (Chelyabinsk Electro-Metallurgical Works OJSC). The particles were characterized using dynamic light scattering, atomic force, and hyperspectral microscopy. According to chemical composition, the fly ash studied was ferro-alumino-silicate mineral containing substantial quantities of Ca, Mg, and a negligible concentration of K, Na, Mn, and Sr. The toxicity of the fly ash microparticles was assessed in vitro using HeLa cells (human cervical cancer cells) and Jurkat cells (immortalized human T lymphocytes). Incubation of cells with different concentrations of fly ash resulted in a dose-dependent decrease in cell viability for all fly ash variants. The most prominent cytotoxic effect in HeLa cells was produced by the ash particles from Rockdale, while the least was produced by the fly ash from Chelyabinsk. In Jurkat cells, the lowest toxicity was observed for fly ash collected from Rockport, Dolet Hill and Muscogee plants. The fly ash from Rockdale and Chelyabinsk induced DNA damage in HeLa cells, as revealed by the single cell electrophoresis, and disrupted the normal nuclear morphology. The interaction of fly ash microparticles of different origins with cells was visualized using dark-field microscopy and hyperspectral imaging. The size of ash particles appeared to be an important determinant of their toxicity, and the smallest fly ash particles from Chelyabinsk turned out to be the most cytotoxic to Jukart cells and the most genotoxic to HeLa cells.
Collapse
Affiliation(s)
- Elvira Rozhina
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
| | - Ilnur Ishmukhametov
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
| | - Läysän Nigamatzyanova
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
| | - Farida Akhatova
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
| | - Svetlana Batasheva
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
| | - Sergey Taskaev
- Physics Department, Chelyabinsk State University, 129 Bratiev Kashirinykh St., 454001 Chelyabinsk, Russia;
| | - Carlos Montes
- Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, USA; (C.M.); (Y.L.)
| | - Yuri Lvov
- Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, USA; (C.M.); (Y.L.)
| | - Rawil Fakhrullin
- Bionanotechnology Lab, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kreml Uramı 18, 420008 Kazan, Republic of Tatarstan, Russia; (E.R.); (I.I.); (L.N.); (F.A.); (S.B.)
- Correspondence:
| |
Collapse
|
4
|
Abstract
An investigation into the potential toxicological effects of fracking sand dust (FSD), collected from unconventional gas drilling sites, has been undertaken, along with characterization of their chemical and biophysical properties. Using intratracheal instillation of nine FSDs in rats and a whole body 4-d inhalation model for one of the FSDs, i.e., FSD 8, and related in vivo and in vitro experiments, the effects of nine FSDs on the respiratory, cardiovascular and immune systems, brain and kidney were reported in the preceding eight tandem papers. Here, a summary is given of the key observations made in the organ systems reported in the individual studies. The major finding that inhaled FSD 8 elicits responses in extra-pulmonary organ systems is unexpected, as is the observation that the pulmonary effects of inhaled FSD 8 are attenuated relative to forms of crystalline silica more frequently used in animal studies, i.e., MIN-U-SIL® 5. An attempt is made to understand the basis for the extra-pulmonary toxicity and comparatively attenuated pulmonary toxicity of FSD 8.
Collapse
|
5
|
Fedan JS. Biological effects of inhaled hydraulic fracturing sand dust. I. Scope of the investigation. Toxicol Appl Pharmacol 2020; 409:115329. [PMID: 33181145 PMCID: PMC7745082 DOI: 10.1016/j.taap.2020.115329] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hydraulic fracturing ("fracking") is a process in which subterranean natural gas-laden rock is fractured under pressure to enhance retrieval of gas. Sand (a "proppant") is present in the fracking fluid pumped down the well bore to stabilize the fissures and facilitate gas flow. The manipulation of sand at the well site creates respirable dust (fracking sand dust, FSD) to which workers are exposed. Because workplace exposures to FSD have exceeded exposure limits set by OSHA, a physico-chemical characterization of FSD along with comprehensive investigations of the potential early adverse effects of FSDs on organ function and biomarkers has been conducted using a rat model and related in vivo and in vitro experiments involving the respiratory, cardiovascular, immune systems, kidney and brain. An undercurrent theme of the overall hazard identification study was, to what degree do the health effects of inhaled FSD resemble those previously observed after crystalline silica dust inhalation? In short-term studies, FSD was found to be less bioactive than MIN-U-SIL® 5 in the lungs. A second theme was, are the biological effects of FSD restricted to the lungs? Bioactivity of FSD was observed in all examined organ systems. Our findings indicate that, in many respects, the physical and chemical properties, and the short-term biological effects, of the FSDs share many similarities as a group but have little in common with crystalline silica dust.
Collapse
Affiliation(s)
- Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America.
| |
Collapse
|
6
|
Olgun NS, Morris AM, Stefaniak AB, Bowers LN, Knepp AK, Duling MG, Mercer RR, Kashon ML, Fedan JS, Leonard SS. Biological effects of inhaled hydraulic fracturing sand dust. III. Cytotoxicity and pro-inflammatory responses in cultured murine macrophage cells. Toxicol Appl Pharmacol 2020; 408:115281. [PMID: 33065155 PMCID: PMC7952011 DOI: 10.1016/j.taap.2020.115281] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 12/16/2022]
Abstract
Cultured murine macrophages (RAW 264.7) were used to investigate the effects of fracking sand dust (FSD) for its pro-inflammatory activity, in order to gain insight into the potential toxicity to workers associated with inhalation of FSD during hydraulic fracturing. While the role of respirable crystalline silica in the development of silicosis is well documented, nothing is known about the toxicity of inhaled FSD. The FSD (FSD 8) used in these studies was from an unconventional gas well drilling site. FSD 8was prepared as a 10 mg/ml stock solution in sterile PBS, vortexed for 15 s, and allowed to sit at room temperature for 30 min before applying the suspension to RAW 264.7cells. Compared to PBS controls, cellular viability was significantly decreased after a 24 h exposure to FSD. Intracellular reactive oxygen species (ROS) production and the production of IL-6, TNFα, and endothelin-1 (ET-1) were up-regulated as a result of the exposure, whereas the hydroxyl radical (.OH) was only detected in an acellular system. Immunofluorescent staining of cells against TNFα revealed that FSD 8 caused cellular blebbing, and engulfment of FSD 8 by macrophages was observed with enhanced dark-field microscopy. The observed changes in cellular viability, cellular morphology, free radical generation and cytokine production all confirm that FSD 8 is cytotoxic to RAW 264.7 cells and warrants future studies into the specific pathways and mechanisms by which these toxicities occur.
Collapse
Affiliation(s)
- Nicole S Olgun
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America.
| | - Anna M Morris
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Aleksandr B Stefaniak
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Lauren N Bowers
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Alycia K Knepp
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Matthew G Duling
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Robert R Mercer
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Stephen S Leonard
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| |
Collapse
|
7
|
Anderson SE, Shane H, Long C, Marrocco A, Lukomska E, Roberts JR, Marshall N, Fedan JS. Biological effects of inhaled hydraulic fracturing sand dust. VIII. Immunotoxicity. Toxicol Appl Pharmacol 2020; 408:115256. [PMID: 33007384 PMCID: PMC7796771 DOI: 10.1016/j.taap.2020.115256] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 11/28/2022]
Abstract
Hydraulic fracturing ("fracking") is a process used to enhance retrieval of gas from subterranean natural gas-laden rock by fracturing it under pressure. Sand used to stabilize fissures and facilitate gas flow creates a potential occupational hazard from respirable fracking sand dust (FSD). As studies of the immunotoxicity of FSD are lacking, the effects of whole-body inhalation (6 h/d for 4 d) of a FSD, i.e., FSD 8, was investigated at 1, 7, and 27 d post-exposure in rats. Exposure to 10 mg/m3 FSD 8 resulted in decreased lung-associated lymph node (LLN) cellularity, total B-cells, CD4+ T-cells, CD8+ T-cells and total natural killer (NK) cells at 7-d post exposure. The frequency of CD4+ T-cells decreased while the frequency of B-cells increased (7 and 27 d) in the LLN. In contrast, increases in LLN cellularity and increases in total CD4+ and CD8+ T-cells were observed in rats following 30 mg/m3 FSD 8 at 1 d post-exposure. Increases in the frequency and number of CD4+ T-cells and NK cells were observed in bronchial alveolar lavage fluid at 7-d post-exposure (10 mg/m3) along with an increase in total CD4+ T-cells, CD11b + cells, and NK cells at 1-day post-exposure (30 mg/m3). Increases in the numbers of B-cells and CD8+ T-cells were observed in the spleen at 1-day post 30 mg/m3 FSD 8 exposure. In addition, NK cell activity was suppressed at 1 d (30 mg/m3) and 27 d post-exposure (10 mg/m3). No change in the IgM response to sheep red blood cells was observed. The findings indicate that FSD 8 caused alterations in cellularity, phenotypic subsets, and impairment of immune function.
Collapse
Affiliation(s)
- Stacey E Anderson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America.
| | - Hillary Shane
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Carrie Long
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Antonella Marrocco
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Ewa Lukomska
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Jenny R Roberts
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Nikki Marshall
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| |
Collapse
|
8
|
Sager TM, Roberts JR, Umbright CM, Barger M, Kashon ML, Fedan JS, Joseph P. Biological effects of inhaled hydraulic fracturing sand dust. V. Pulmonary inflammatory, cytotoxic and oxidant effects. Toxicol Appl Pharmacol 2020; 408:115280. [PMID: 33065154 PMCID: PMC7748298 DOI: 10.1016/j.taap.2020.115280] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 11/24/2022]
Abstract
The pulmonary inflammatory response to inhalation exposure to a fracking sand dust (FSD 8) was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol of a FSD, i.e., FSD 8, at concentrations of 10 or 30 mg/m3, 6 h/d for 4 d. The control and FSD 8-exposed rats were euthanized at post-exposure time intervals of 1, 7 or 27 d and pulmonary inflammatory, cytotoxic and oxidant responses were determined. Deposition of FSD 8 particles was detected in the lungs of all the FSD 8-exposed rats. Analysis of bronchoalveolar lavage parameters of toxicity, oxidant generation, and inflammation did not reveal any significant persistent pulmonary toxicity in the FSD 8-exposed rats. Similarly, the lung histology of the FSD 8-exposed rats showed only minimal changes in influx of macrophages following the exposure. Determination of global gene expression profiles detected statistically significant differential expressions of only six and five genes in the 10 mg/m3, 1-d post-exposure, and the 30 mg/m3, 7-d post-exposure FSD 8 groups, respectively. Taken together, data obtained from the present study demonstrated that FSD 8 inhalation exposure resulted in no statistically significant toxicity or gene expression changes in the lungs of the rats. In the absence of any information about its potential toxicity, a comprehensive rat animal model study (see Fedan, J.S., Toxicol Appl Pharmacol. 000, 000-000, 2020) has been designed to investigate the bioactivities of several FSDs in comparison to MIN-U-SIL® 5, a respirable α-quartz reference dust used in previous animal models of silicosis, in several organ systems.
Collapse
Affiliation(s)
- Tina M Sager
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America.
| | - Jenny R Roberts
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| | - Christina M Umbright
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| | - Mark Barger
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| | - Pius Joseph
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, United States of America
| |
Collapse
|
9
|
Krajnak K, Kan H, Russ KA, McKinney W, Waugh S, Zheng W, Kashon ML, Johnson C, Cumpston J, Fedan JS. Biological effects of inhaled hydraulic fracturing sand dust. VI. Cardiovascular effects. Toxicol Appl Pharmacol 2020; 406:115242. [PMID: 32931794 DOI: 10.1016/j.taap.2020.115242] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/27/2020] [Accepted: 09/09/2020] [Indexed: 12/24/2022]
Abstract
Hydraulic fracturing is used to access oil and natural gas reserves. This process involves the high-pressure injection of fluid to fracture shale. Fracking fluid contains approximately 95% water, chemicals and 4.5% fracking sand. Workers may be exposed to fracking sand dust (FSD) during the manipulation of the sand, and negative health consequences could occur if FSD is inhaled. In the absence of any information about its potential toxicity, a comprehensive rat animal model study (see Fedan et al., 2020) was designed to investigate the bioactivities of several FSDs in comparison to MIN-U-SIL® 5, a respirable α-quartz reference dust used in previous animal models of silicosis, in several organ systems. The goal of this study was to assess the effects of inhalation of one FSD, i.e., FSD 8, on factors and tissues that affect cardiovascular function. Male rats were exposed to 10 or 30 mg/m3 FSD (6 h/d for 4 d) by whole body inhalation, with measurements made 1, 7 or 27 d post-exposure. One day following exposure to 10 mg/m3 FSD the sensitivity to phenylephrine-induced vasoconstriction in tail arteries in vitro was increased. FSD exposure at both doses resulted in decreases in heart rate (HR), HR variability, and blood pressure in vivo. FSD induced changes in hydrogen peroxide concentrations and transcript levels for pro-inflammatory factors in heart tissues. In kidney, expression of proteins indicative of injury and remodeling was reduced after FSD exposure. When analyzed using regression analysis, changes in proteins involved in repair and remodeling were correlated. Thus, it appears that inhalation of FSD does have some prolonged effects on cardiovascular, and, possibly, renal function. The findings also provide information regarding potential mechanisms that may lead to these changes, and biomarkers that could be examined to monitor physiological changes that could be indicative of impending cardiovascular dysfunction.
Collapse
Affiliation(s)
- Kristine Krajnak
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America.
| | - Hong Kan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Kristen A Russ
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Walter McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Stacey Waugh
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Wen Zheng
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Claud Johnson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Jared Cumpston
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States of America
| |
Collapse
|
10
|
Biological effects of inhaled hydraulic fracturing sand dust VII. Neuroinflammation and altered synaptic protein expression. Toxicol Appl Pharmacol 2020; 409:115300. [PMID: 33141058 DOI: 10.1016/j.taap.2020.115300] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 12/26/2022]
Abstract
Hydraulic fracturing (fracking) is a process used to recover oil and gas from shale rock formation during unconventional drilling. Pressurized liquids containing water and sand (proppant) are used to fracture the oil- and natural gas-laden rock. The transportation and handling of proppant at well sites generate dust aerosols; thus, there is concern of worker exposure to such fracking sand dusts (FSD) by inhalation. FSD are generally composed of respirable crystalline silica and other minerals native to the geological source of the proppant material. Field investigations by NIOSH suggest that the levels of respirable crystalline silica at well sites can exceed the permissible exposure limits. Thus, from an occupational safety perspective, it is important to evaluate the potential toxicological effects of FSD, including any neurological risks. Here, we report that acute inhalation exposure of rats to one FSD, i.e., FSD 8, elicited neuroinflammation, altered the expression of blood brain barrier-related markers, and caused glial changes in the olfactory bulb, hippocampus and cerebellum. An intriguing observation was the persistent reduction of synaptophysin 1 and synaptotagmin 1 proteins in the cerebellum, indicative of synaptic disruption and/or injury. While our initial hazard identification studies suggest a likely neural risk, more research is necessary to determine if such molecular aberrations will progressively culminate in neuropathology/neurodegeneration leading to behavioral and/or functional deficits.
Collapse
|
11
|
Biological effects of inhaled hydraulic fracturing sand dust. II. Particle characterization and pulmonary effects 30 d following intratracheal instillation. Toxicol Appl Pharmacol 2020; 409:115282. [PMID: 33068622 DOI: 10.1016/j.taap.2020.115282] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 01/29/2023]
Abstract
Hydraulic fracturing ("fracking") is used in unconventional gas drilling to allow for the free flow of natural gas from rock. Sand in fracking fluid is pumped into the well bore under high pressure to enter and stabilize fissures in the rock. In the process of manipulating the sand on site, respirable dust (fracking sand dust, FSD) is generated. Inhalation of FSD is a potential hazard to workers inasmuch as respirable crystalline silica causes silicosis, and levels of FSD at drilling work sites have exceeded occupational exposure limits set by OSHA. In the absence of any information about its potential toxicity, a comprehensive rat animal model was designed to investigate the bioactivities of several FSDs in comparison to MIN-U-SIL® 5, a respirable α-quartz reference dust used in previous animal models of silicosis, in several organ systems (Fedan, J.S., Toxicol Appl Pharmacol. 00, 000-000, 2020). The present report, part of the larger investigation, describes: 1) a comparison of the physico-chemical properties of nine FSDs, collected at drilling sites, and MIN-U-SIL® 5, a reference silica dust, and 2) a comparison of the pulmonary inflammatory responses to intratracheal instillation of the nine FSDs and MIN-U-SIL® 5. Our findings indicate that, in many respects, the physico-chemical characteristics, and the biological effects of the FSDs and MIN-U-SIL® 5 after intratracheal instillation, have distinct differences.
Collapse
|