1
|
Zhang WH, Deng YD, Chen ZF, Zuo ZH, Tian YS, Xu J, Wang B, Wang LJ, Han HJ, Li ZJ, Wang Y, Yao QH, Gao JJ, Fu XY, Peng RH. Metabolic engineering of Escherichia coli for 2,4-dinitrotoluene degradation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115287. [PMID: 37567105 DOI: 10.1016/j.ecoenv.2023.115287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/15/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023]
Abstract
2,4-Dinitrotoluene (2,4-DNT) as a common industrial waste has been massively discharged into the environment with industrial wastewater. Due to its refractory degradation, high toxicity, and bioaccumulation, 2,4-DNT pollution has become increasingly serious. Compared with the currently available physical and chemical methods, in situ bioremediation is considered as an economical and environmentally friendly approach to remove toxic compounds from contaminated environment. In this study, we relocated a complete degradation pathway of 2,4-DNT into Escherichia coli to degrade 2,4-DNT completely. Eight genes from Burkholderia sp. strain were re-synthesized by PCR-based two-step DNA synthesis method and introduced into E. coli. Degradation experiments revealed that the transformant was able to degrade 2,4-DNT completely in 12 h when the 2,4-DNT concentration reached 3 mM. The organic acids in the tricarboxylic acid cycle were detected to prove the degradation of 2,4-DNT through the artificial degradation pathway. The results proved that 2,4-DNT could be completely degraded by the engineered bacteria. In this study, the complete degradation pathway of 2,4-DNT was constructed in E. coli for the first time using synthetic biology techniques. This research provides theoretical and experimental bases for the actual treatment of 2,4-DNT, and lays a technical foundation for the bioremediation of organic pollutants.
Collapse
Affiliation(s)
- Wen-Hui Zhang
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Yong-Dong Deng
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Zhi-Feng Chen
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Zhi-Hao Zuo
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Yong-Sheng Tian
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Jing Xu
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Bo Wang
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Li-Juan Wang
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Hong-Juan Han
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Zhen-Jun Li
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Yu Wang
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Quan-Hong Yao
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China
| | - Jian-Jie Gao
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China.
| | - Xiao-Yan Fu
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China.
| | - Ri-He Peng
- Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, China; Key Laboratory for Safety Assessment (Environment) of Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, China.
| |
Collapse
|
2
|
Shahrokhi F, Zhao Y. A tetrathiafulvalene vinylogue-based double-layer polymer thin film as a highly sensitive and selective TNT sensor. NEW J CHEM 2019. [DOI: 10.1039/c8nj06467a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A double-layer redox-active polymer thin film acts as a highly efficient TNT electrochemical sensor.
Collapse
Affiliation(s)
- Farshid Shahrokhi
- Department of Chemistry
- Memorial University of Newfoundland
- St. John's
- Canada
| | - Yuming Zhao
- Department of Chemistry
- Memorial University of Newfoundland
- St. John's
- Canada
| |
Collapse
|
3
|
Peckham TK, Shirai JH, Bunge AL, Lowney YW, Ruby MV, Kissel JC. Dermal absorption of benzo[a]pyrene into human skin from soil: Effect of artificial weathering, concentration, and exposure duration. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2017; 27:610-617. [PMID: 27805623 DOI: 10.1038/jes.2016.61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/01/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
In vitro assessments of 14C-benzo[a]pyrene (BaP) absorption through human epidermis were conducted with the sub-63-μm fraction of four test soils containing different amounts of organic and black carbon. Soils were artificially weathered for eight weeks and applied to epidermis at nominal BaP concentrations of 3 and 10 mg/kg for 8 or 24 h. Experiments were also conducted at 24 h with unweathered soils and with BaP deposited onto skin from acetone at a comparable chemical load. For the weathered soils, absorption was independent of the amount of organic or black carbon, the mass in the receptor fluid was proportional to exposure duration but independent of concentration, and the mass recovered in the skin after washing was proportional to concentration and independent of exposure time. Results from the weathered and unweathered soils were similar except for the mass recovered in the washed skin, which was lower for the weathered soil only at the higher concentration. We hypothesize that chemical concentrations exceeded the BaP sorption capacity accessible within the artificial weathering timeframe for all soils tested, and that BaP mass in the washed skin was dominated by particles that were not removed by washing. Fluxes into and through skin from soils were lower by an order of magnitude than from acetone-deposited BaP.
Collapse
Affiliation(s)
- Trevor K Peckham
- Department of Environmental and Occupational Health Services, School of Public Health, University of Washington, Seattle, WA, USA
| | - Jeffry H Shirai
- Department of Environmental and Occupational Health Services, School of Public Health, University of Washington, Seattle, WA, USA
| | - Annette L Bunge
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, CO, USA
| | | | | | - John C Kissel
- Department of Environmental and Occupational Health Services, School of Public Health, University of Washington, Seattle, WA, USA
| |
Collapse
|
4
|
Tang N, Mu L, Qu H, Wang Y, Duan X, Reed MA. Smartphone-Enabled Colorimetric Trinitrotoluene Detection Using Amine-Trapped Polydimethylsiloxane Membranes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:14445-14452. [PMID: 28383246 DOI: 10.1021/acsami.7b03314] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A smartphone-enabled platform for easy and portably colorimetric analysis of 2,4,6-trinitrotoluene (TNT) using amine-trapped PDMS is designed and implemented. The amine-trapped polydimethylsiloxane (PDMS) is simply prepared by immersing the cured PDMS in aminosilane solutions forming an amine-containing polymer. After contacting with TNT-containing solutions, the colorless PDMS showed a rapid colorimetric change which can be easily identified by the naked eye. The amine-trapped PDMS was carefully optimized to achieve visible detection of TNT at concentrations as low as 1 μM. Using an integrated camera in the smartphone, pictures of colored PDMS membranes can be analyzed by a home-developed mobile application. Thus, the TNT amount can be precisely quantified. Direct TNT detection in real samples (e.g., drinking, tap, and lake waters) is demonstrated as well. The smartphone-enabled colorimetric method using amine-trapped PDMS membranes realizes a convenient and efficient approach toward a portable system for field TNT detections.
Collapse
Affiliation(s)
- Ning Tang
- State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University , Tianjin 300072, China
| | - Luye Mu
- State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University , Tianjin 300072, China
| | - Hemi Qu
- State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University , Tianjin 300072, China
| | - Yanyan Wang
- State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University , Tianjin 300072, China
| | - Xuexin Duan
- State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University , Tianjin 300072, China
| | | |
Collapse
|
5
|
Abstract
Sulfur mustard (HD) undergoes hydrolysis to form various products such as thiodiglycol (TG) in biological and environmental systems. TG is a precursor in the production of HD and it is also considered as a “Schedule 2” compound (dual-use chemicals with low to moderate commercial use and high-risk precursors). Several toxicological studies on TG were conducted to assess environmental and health effects. The oral LD50 values were >5000 mg/kg in rats. It was a mild skin and moderate ocular irritant and was not a skin sensitizer in animals. It was not mutagenic in Ames Salmonella, Escherichia coli, mouse lymphoma, and in vivo mouse micronucleus assays, but it induced chromosomal aberrations in Chinese hamster ovarian (CHO) cells. A 90-day oral subchronic toxicity study with neat TG at doses of 0, 50, 500, and 5000 mg/kg/day (5 days/week) in Sprague-Dawley rats results show that there are no treatment-related changes in food consumption, hematology, and clinical chemistry in rats of either sex. The body weights of both sexes were significantly lower than controls at 5000 mg/kg/day. Significant changes were also noted in both sexes in absolute weights of kidneys, kidney to body weight ratios, and kidney to brain weight ratios, in the high-dose group. The no-observed-adverse-effect level (NOAEL) for oral toxicity was 500 mg/kg/day. The developmental toxicity conducted at 0, 430, 1290, and 3870 mg/kg by oral gavage showed maternal toxicity in dams receiving 3870 mg/kg. TG was not a developmental toxicant. The NOAEL for the developmental toxicity in rats was 1290 mg/kg. The provisional oral reference dose (RfD) of 0.4 mg/kg/day was calculated for health risk assessments. The fate of TG in the environment and soil showed biological formation of thiodiglycalic acid with formation of an intermediate ((2-hydroxyethyl)thio)acetic acid. It was slowly biodegraded under anaerobic conditions. It was not toxic to bluegill sunfish at 1000 mg/L and its metabolism and environmental and biochemical effects are summarized.
Collapse
Affiliation(s)
- Gunda Reddy
- Directorate of Toxicology, U.S. Army Center for Health Promotion and Preventive Medicine, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5403, USA.
| | | | | |
Collapse
|
6
|
Human skin in vitro permeation of bentazon and isoproturon formulations with or without protective clothing suit. Arch Toxicol 2013; 88:77-88. [PMID: 23820846 DOI: 10.1007/s00204-013-1087-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
Abstract
Skin exposures to chemicals may lead, through percutaneous permeation, to a significant increase in systemic circulation. Skin is the primary route of entry during some occupational activities, especially in agriculture. To reduce skin exposures, the use of personal protective equipment (PPE) is recommended. PPE efficiency is characterized as the time until products permeate through material (lag time, Tlag). Both skin and PPE permeations are assessed using similar in vitro methods; the diffusion cell system. Flow-through diffusion cells were used in this study to assess the permeation of two herbicides, bentazon and isoproturon, as well as four related commercial formulations (Basagran(®), Basamais(®), Arelon(®) and Matara(®)). Permeation was measured through fresh excised human skin, protective clothing suits (suits) (Microchem(®) 3000, AgriSafe Pro(®), Proshield(®) and Microgard(®) 2000 Plus Green), and a combination of skin and suits. Both herbicides, tested by itself or as an active ingredient in formulations, permeated readily through human skin and tested suits (Tlag < 2 h). High permeation coefficients were obtained regardless of formulations or tested membranes, except for Microchem(®) 3000. Short Tlag, were observed even when skin was covered with suits, except for Microchem(®) 3000. Kp values tended to decrease when suits covered the skin (except when Arelon(®) was applied to skin covered with AgriSafe Pro and Microgard(®) 2000), suggesting that Tlag alone is insufficient in characterizing suits. To better estimate human skin permeations, in vitro experiments should not only use human skin but also consider the intended use of the suit, i.e., the active ingredient concentrations and type of formulations, which significantly affect skin permeation.
Collapse
|
7
|
Bell SC, Gayton-Ely M, Nida CM. Bioassays for bomb-makers: proof of concept. Anal Bioanal Chem 2009; 395:401-9. [PMID: 19484462 DOI: 10.1007/s00216-009-2851-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 04/29/2009] [Accepted: 05/12/2009] [Indexed: 11/29/2022]
Abstract
Clandestine bomb-makers are exposed to significant amounts of explosives and allied materials. As with any ingested xenobiotic substance, these compounds are subject to biotransformation. As such, the potential exists that characteristic suites of biomarkers may be produced and deposited in matrices that can be exploited for forensic and investigative purposes. However, before such assays can be developed, foundational data must be gathered regarding the toxicokinetics, fate, and transport of the resulting biomarkers within the body and in matrices such as urine, hair, nails, sweat, feces, and saliva. This report presents an in vitro method for simulation of human metabolic transformations using human liver microsomes and an assay applicable to representative nitro-explosives. Control and metabolized samples of TNT, RDX, HMX, and tetryl were analyzed using high-performance liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) and biomarkers identified for each. The challenges associated with this method arise from solubility issues and limitations imposed by instrumentation, specifically, modes of ionization.
Collapse
Affiliation(s)
- Suzanne C Bell
- Forensic Science & Chemistry, West Virginia University, 1600 University Avenue, Oglebay Hall, Room 208, Box 6121, Morgantown, WV 26506-6121, USA.
| | | | | |
Collapse
|
8
|
Spalt EW, Kissel JC, Shirai JH, Bunge AL. Dermal absorption of environmental contaminants from soil and sediment: a critical review. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2009; 19:119-148. [PMID: 18830234 DOI: 10.1038/jes.2008.57] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 08/04/2008] [Indexed: 05/26/2023]
Abstract
Risk assessment of hazardous wastes sites may require characterization of the dermal availability of chemical contaminants in soil and/or sediment. Current U.S. Environmental Protection Agency guidance for assessment of dermal exposures to contaminants in water and soil was finalized in 2004 as a supplement (Part E) to the Risk Assessment Guidance for Superfund (RAGS). The soil protocol presented in RAGS Part E is less sophisticated than the water protocol and is supported by less empirical data. Investigations of dermal absorption of soil and sediment-borne contaminants that have been conducted to date include in vitro and in vivo experiments using both human and surrogate skin. A review of that literature was conducted with attention to relevant criteria including consideration of layering effects, degree of chemical saturation of soil, appropriateness of particle size distribution employed, soil-chemical contact time, and continuity of soil-skin contact (in in vivo studies). Most studies published to date are deficient by virtue of execution or reporting on one or more of the selected criteria. In addition the lack of methodological standardization evident in the literature hinders systematic evaluation of results. Since additional experimental work is needed, general agreement on acceptable approaches would be useful. Recommendations for good practice are presented.
Collapse
Affiliation(s)
- Elizabeth W Spalt
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195-4695, USA
| | | | | | | |
Collapse
|
9
|
Reifenrath WG, Olson JJ, Vedula U, Osimitz TG. Percutaneous absorption of an insect repellent p-menthane-3,8-DIOL: a model for human dermal absorption. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:796-806. [PMID: 19557607 DOI: 10.1080/15287390902800371] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
p-Menthane-3,8-diol(38DIOL) was recently introduced as a natural topical insect repellent in the commercial product "OFF! Botanicals" lotion. The objective of this study was to provide an estimate of the potential for 38DIOL systemic absorption in humans. Carbon-14-labeled 38DIOL formulated in the lotion and in an ethanol solution was applied to excised pig skin in an in vitro flow-through test system predictive of skin absorption in humans. Twenty-four hours after application, radiolabel recovered from the dermis and receptor fluid was summed to determine percent absorption. At a dose of approximately 80 microg/cm(2) of 38DIOL in the lotion, a value of 3.5 +/- 0.8% of applied dose was obtained with pig skin. The corresponding value for 38DIOL in ethanol (90 microg/cm(2)) was not significantly different (3.0 +/- 1.2%). Most of the applied dose of 38DIOL was found to evaporate from pig skin (77 +/- 8% for the lotion and 87 +/- 1% for ethanol solution), thus limiting percutaneous absorption values. For reference purposes, the pig skin absorptions of piperonyl butoxide (PBO) at 100 microg/cm(2) in isopropanol, N,N-diethyl-m-toluamide (DEET) at 500 microg/cm(2) in ethanol, and neat isododecane at 650 microg/cm(2) (in order of increasing volatility) were 15 +/- 6%, 23 +/- 3%, and 0.09 +/- 0.05% of applied dose respectively. Isododecane was lost almost exclusively from the skin surface by evaporation. For additional reference, absorptions of PBO, DEET, and 38DIOL were found to be higher with excised rat skin.
Collapse
|
10
|
Roy TA, Hammerstrom K, Schaum J. Percutaneous absorption of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) from soil. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:350-357. [PMID: 19184751 DOI: 10.1080/15287390802529955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Six dermal absorption experiments (one in vivo, five in vitro) were conducted using 3,3',4,4'-tetrachlorobiphenyl (TCB) either neat at 141 microg/cm2 or sorbed on a low organic (LOS) or high organic (HOS) soil at 6-10 microg/cm2. All soil experiments were conducted at 1000 ppm and soil loads of 6-10 mg soil/cm(2). After 96 h the percentage of applied dose absorbed (PADA) for TCB sorbed on LOS was 49.7 (rat, in vivo), 31.9 (rat, in vitro), and 7.4 (human, in vitro). The 96-h PADA for TCB sorbed on HOS was 9.6% (rat, in vitro). Generally, rat skin was observed to be four- to ninefold more permeable to TCB than human skin (in vitro). At steady state, the dermal flux of TCB on LOS at 1000 ppm and on HOS at 1000 ppm (both in vitro, rat) was 33 and 10 ng/cm2/h, respectively (ratio = 3.3).
Collapse
Affiliation(s)
- Timothy A Roy
- Port Royal Research, Hilton Head, South Carolina, USA
| | | | | |
Collapse
|
11
|
Reddy G, Allen NA, Major MA. Absorption of14C-Cyclotrimethylenetrinitramine (RDX) from Soils through Excised Human Skin. Toxicol Mech Methods 2008; 18:575-9. [DOI: 10.1080/15376510701703466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
12
|
Crouse LCB, Michie MW, Major MA, Leach GJ, Reddy G. Oral Bioavailability of Cyclotrimethylenetrinitramine (RDX) from Contaminated Site Soils in Rats. Int J Toxicol 2008; 27:317-22. [DOI: 10.1080/10915810802366885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Cyclotrimethylenetrinitramine (RDX), a commonly used military explosive, was detected as a contaminant of soil and water at Army facilities and ranges. This study was conducted to determine the relative oral bioavailability of RDX in contaminated soil and to develop a method to derive bioavailability adjustments for risk assessments using rodents. Adult male Sprague-Dawley rats preimplanted with femoral artery catheters were dosed orally with gelatin capsules containing either pure RDX or an equivalent amount of RDX in contaminated soils from Louisiana Army Ammunition Plant (LAAP) (2300 μg/g of soil) or Fort Meade (FM) (670 μg/g of soil). After dosing rats, blood samples were collected from catheters at 2-h intervals (2, 4, 6, 8, 10, and 12) and at 24 and 48 h. RDX levels in the blood were determined by gas chromatography. The results show that the peak absorption of RDX in blood was 6 h for neat RDX (1.24 mg/kg) and for RDX from contaminated soil (1.24 mg/kg) of LAAP. Rats dosed with RDX-contaminated FM soil (0.2 mg/kg) showed peak levels of RDX in blood at 6 h, whereas their counterparts that received an identical dose (0.2 mg/kg) of neat RDX showed peak absorption at 4 h. The blood levels of absorbed RDX from LAAP soil were about 25% less than for neat RDX, whereas the bioavailability of RDX from FM soils was about 15% less than that seen in rats treated with neat RDX (0.2 mg/kg). The oral bioavailability in rats fed RDX in LAAP soil and the FM soil was reduced with the neat compound but decrease in bioavailability varied with the soil type.
Collapse
Affiliation(s)
- Lee C. B. Crouse
- Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland, USA
| | - Mark W. Michie
- Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland, USA
| | - Michael A. Major
- Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland, USA
| | - Glenn J. Leach
- Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland, USA
| | - Gunda Reddy
- Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland, USA
| |
Collapse
|
13
|
Reifenrath WG, Kammen HO, Reddy G, Major MA, Leach GJ. Interaction of hydration, aging, and carbon content of soil on the evaporation and skin bioavailability of munition contaminants. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2008; 71:486-494. [PMID: 18338283 DOI: 10.1080/15287390801906956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Water plays a key role in enhancing the permeability of human skin to many substances. To further understand its ability to potentially increase the bioavailability of soil contaminants, artificial sweat was applied to excised pig skin prior to dosing with munition-contaminated soils. Skin was mounted in chambers to allow simultaneous measurement of evaporation and penetration and to control air flow, which changed the dwell time of skin surface water within a l-h period post application of test materials. Additional variables included type of compound, aging of spiked soil samples, and carbon content of soil. To this end, the evaporation and skin penetration of C-14 labeled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,6-dinitrotoluene (26DNT), and 2,4,6-trinitrotoluene (TNT) were determined from two soil types, Yolo, having 1.2% carbon, and Tinker, having 9.5% carbon. RDX soil samples aged 27 mo and 62 mo were compared to freshly spiked soils samples. Similarly, 26DNT samples aged 35-36 mo and TNT samples aged 18 mo were compared to freshly spiked samples. Approximately 10 microg/cm(2) of radiolabeled compound was applied in 10 mg/cm(2) of soil. Radiolabel recovered from the dermis and tissue culture media (receptor fluid) was summed to determine percent absorption from the soils. Radiolabel recovered from vapor traps determined evaporation. Mean skin absorption of all compounds was higher for low-carbon soil, regardless of soil age and skin surface water as affected by air flow conditions. For 26DNT, a simultaneous increase in evaporation and penetration with conditions that favored enhanced soil hydration of freshly prepared samples was consistent with a mechanism that involved water displacement of 26DNT from its binding sites. A mean penetration of 17.5 +/- 3.6% was observed for 26DNT in low-carbon soil, which approached the value previously reported for acetone vehicle (24 +/- 6%). 26DNT penetration was reduced to 0.35% under dryer conditions and to 0.08% when no sweat was applied. When soil hydration conditions were not varied from cell to cell, air flow that favored a longer water dwell time increased penetration, but not evaporation, consistent with a mechanism of enhanced skin permeability from a higher hydration state of the stratum corneum. Profiles of 26DNT penetration versus air flow conditions were exponential for freshly prepared soil samples, suggesting strong and weak binding sites; corresponding profiles of 26DNT penetration from aged samples were linear, suggesting a conversion of weak to strong binding sites. Absorption and evaporation was less than 5% for TNT and less than 1% for RDX, regardless of soil type and age. Fresh preparations of RDX in Tinker soil and aged samples of TNT in Yolo soil showed a significant decrease in skin absorption with loss of surface moisture. The penetration rate of radiolabel into the receptor fluid was highest during the 1-2 h interval after dosing with 26DNT or TNT. High-performance liquid chromatography (HPLC) analysis of 26DNT in receptor fluid at maximum flux indicated no metabolism or breakdown. For TNT, however, extensive conversion to monoamino derivatives and other metabolites was observed. Relatively little radioactivity was found in the dermis after 26DNT and TNT applications, and dermal extracts were therefore not analyzed by HPLC. RDX was not sufficiently absorbed from soils to allow HPLC analysis. This study has practical significance, as the use of water for dust control at remediation sites may have the unintended effect of increasing volatilization and subsequent absorption of soil contaminants. Soil in contact with sweaty skin may give the same result. Skin absorption of 26DNT from soil was over 50-fold higher than the value for dryer skin and over 200-fold higher than the value obtained when there was no sweat application. While the hydration effect was less dramatic for RDX and TNT, soil contaminants more closely matching the physical properties of 26DNT may be similarly affected by hydration.
Collapse
|
14
|
Gaurav D, Malik AK, Rai PK. High-Performance Liquid Chromatographic Methods for the Analysis of Explosives. Crit Rev Anal Chem 2007. [DOI: 10.1080/10408340701244698] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Dhingra Gaurav
- a Department of Chemistry , Punjabi University , Patiala, Punjab, India
| | - Ashok Kumar Malik
- a Department of Chemistry , Punjabi University , Patiala, Punjab, India
| | - P. K. Rai
- b Centre for Fire, Explosives and Environmental Safety , New Delhi, India
| |
Collapse
|
15
|
Crescenzi C, Albiñana J, Carlsson H, Holmgren E, Batlle R. On-line strategies for determining trace levels of nitroaromatic explosives and related compounds in water. J Chromatogr A 2007; 1153:186-93. [PMID: 17141256 DOI: 10.1016/j.chroma.2006.11.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 11/13/2006] [Accepted: 11/16/2006] [Indexed: 10/23/2022]
Abstract
We report the development and tests of several systems for the simultaneous determination of 18 energetic compounds and related congeners in untreated water samples. In these systems a Restricted Access Material trap or liquid-chromatography precolumn (with a C(18) or porous graphitic carbon, PGC, stationary phase) followed by a PGC analytical column are used for sample clean-up, enrichment and separation of the trace level analytes, which are then analyzed by mass spectrometry (MS). The relative merits of two MS ionization interfaces (atmospheric pressure chemical ionization, APCI, and atmospheric pressure photoionization, APPI) were also compared for the MS identification and quantification of these analytes. APCI was found to be superior in cases where both alternatives are applicable. A major drawback when applying APPI is that no signal is obtained for the cyclic nitramines and nitrate esters. Using APCI, a wide spectrum of unstable compounds can be determined in a single analysis, and the feasibility of using large volume samples (up to 100 mL) in combination with the sensitivity of the MS detection system provide method detection limits ranging from 2.5 pg/mL (for 2,4-dinitrotoluene and 2,6-diamino-6-nitrotoluene) to 563 pg/mL (for pentaerythritol tetranitrate, PETN), with repeatability ranging from 2 to 7%. Other chemometric parameters such as robustness, selectivity, repeatability, and intermediate precision were also evaluated in the validation of the extraction methods for use in water analysis. Tests with untreated groundwater and drinking water samples, spiked with 20 ng of the analytes, yielded results similar to those obtained with high purity water samples.
Collapse
Affiliation(s)
- C Crescenzi
- Department of Analytical Chemistry, Stockholm University, S-10691 Stockholm, Sweden
| | | | | | | | | |
Collapse
|
16
|
Johnson MS, Suski J, Bazar MA. Toxicological responses of red-backed salamanders (Plethodon cinereus) to subchronic soil exposures of 2,4-dinitrotoluene. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2007; 147:604-8. [PMID: 17137690 DOI: 10.1016/j.envpol.2006.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 08/11/2006] [Accepted: 10/06/2006] [Indexed: 05/12/2023]
Abstract
Dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. To determine whether concentrations of 2,4-dinitrotoluene (2,4-DNT) in soil are toxic to amphibians, 100 red-backed salamanders (Plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0mg 2,4-DNT/kg soil for 28 days and evaluated for indicators of toxicity. Concentrations of 2,4-DNT were less than targets and varied with time. Most salamanders exposed to concentrations exceeding 1050 mg/kg died or were moribund within the first week. Salamanders exposed to soil concentrations exceeding 345 mg/kg lost >6% of their body mass though no mortality occurred. Overt effects included a reduction in feed consumption and an increase in bucco-pharyngeal oscillations in salamanders. These results suggest that only high soil concentrations of 2,4-DNT have the potential to cause overtly toxic effects in terrestrial salamanders.
Collapse
Affiliation(s)
- Mark S Johnson
- US Army Center for Health Promotion and Preventive Medicine, Health Effects Research Program, MCHB-TS-THE, Aberdeen Proving Ground, MD 21010-5403, USA.
| | | | | |
Collapse
|
17
|
Reifenrath WG. Enhanced skin absorption and fly toxicity of permethrin in emulsion formulation. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2007; 78:299-303. [PMID: 17619804 DOI: 10.1007/s00128-007-9159-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Accepted: 04/29/2007] [Indexed: 05/16/2023]
Affiliation(s)
- W G Reifenrath
- Stratacor, Inc, 1315 So. 46th St., Bldg. 154, Richmond, CA 94804, USA.
| |
Collapse
|
18
|
Williams RL, Reifenrath WG, Krieger RI. Artificial sweat enhances dermal transfer of chlorpyrifos from treated nylon carpet fibers. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2005; 40:535-43. [PMID: 16047878 DOI: 10.1081/pfc-200061525] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The dermal transfer and absorption of 14C-ring-chlorpyrifos from nylon carpet fibers was measured in skin penetration-evaporation cells with excised pig skin. Prior to application, synthetic sweat was applied to skin in half of the cells. Radioactivity was measured in receptor fluid, dermis, epidermis, tape stripping samples, and vapor trap samples during a 24-h period. The sum of radiolabel recovered from the dermis and receptor fluid represented the absorbed dose. There was no significant difference (p > 0.05) in percutaneous absorption between cells that received the synthetic sweat application and "dry" cells (1.3 +/- 0.3% of applied dose). There was significantly more (p < 0.05) radiolabel recovered from tape stripping (5.4 +/- 2.1 vs. 2.8 +/- 0.6%) and in the epidermis (4.5 +/- 0.8 vs. 3.1 +/- 0.3%) from cells that received the synthetic sweat application, which indicated synthetic sweat facilitated transfer of chlorpyrifos from a treated substrate to the skin surface. The measured value for percutaneous absorption of chlorpyrifos agreed with the value predicted from an empirical model previously developed for nitro compound-containing soil.
Collapse
Affiliation(s)
- Ryan L Williams
- Personal Chemical Exposure Program, Department of Entomology, University of California, Riverside, CA 92521, USA
| | | | | |
Collapse
|
19
|
Baynes RE, Barlow BM, Riviere JE. Dermal Disposition of Triazine in Cutting Fluid Mixtures. ACTA ACUST UNITED AC 2003. [DOI: 10.1081/cus-120026301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|