Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel
Objectives The objective of this study was to investigate whether there is a relationship between the external exposure dose of chromium and nickel caused by a metal active gas welding process with a solid high-alloyed steel welding wire and inner exposure of subjects. In order to perform welding fu...
Gespeichert in:
| Veröffentlicht in: | International archives of occupational and environmental health 2013, Vol.86 (1), p.31-37 |
|---|---|
| Hauptverfasser: | , , , , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | 37 |
|---|---|
| container_issue | 1 |
| container_start_page | 31 |
| container_title | International archives of occupational and environmental health |
| container_volume | 86 |
| creator | Gube, Monika Brand, Peter Schettgen, Thomas Bertram, Jens Gerards, Kerstin Reisgen, Uwe Kraus, Thomas |
| description | Objectives
The objective of this study was to investigate whether there is a relationship between the external exposure dose of chromium and nickel caused by a metal active gas welding process with a solid high-alloyed steel welding wire and inner exposure of subjects. In order to perform welding fume exposure under controlled and standardized conditions, the investigations were conducted in the “Aachen Workplace Simulation Laboratory”.
Methods
To perform biological monitoring of chromium and nickel, blood and urine samples of 12 healthy male non-smokers who never worked as welders were collected before and after a 6-h exposure to ambient air (0 mg/m
3
) and to welding fumes of a metal active gas welding process once with a concentration of the welding fume of 1 mg/m
3
and once with a concentration of 2.5 mg/m
3
.
Results
Although the internal exposure to chromium and nickel in this study was comparatively low, the subjects showed significantly increased concentrations of these metals in urine after exposure to welding fume compared to the values at baseline. Moreover, the observed increase was significantly dose dependent for both of the substances.
Conclusion
For the biological monitoring of chromium and nickel in urine of subjects exposed to welding fumes, a dependency on exposure dose was seen under standardized conditions after a single exposure over a period of 6 h. Thus, this study contributes to a better understanding of the relationship between ambient and biological exposures from welding fumes and provides a good basis for evaluating future biological threshold values for these metals in welding occupation. |
| doi_str_mv | 10.1007/s00420-012-0738-8 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_miscellaneous_1352286925</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>1352286925</sourcerecordid><originalsourceid>FETCH-LOGICAL-c435t-2f82f593bf0f9794e8b8965b1f00bd2af4598da1328142fb0b2b5887977811bf3</originalsourceid><addsrcrecordid>eNp1kc1u1DAUhS0EokPhAdggS6gSm4B_8uOwq6oCI1ViA2vLdq47HpI4-CZqu-sLsOMJeRIczfAjJFZe-Dvn3HsPIc85e80Za94gY6VgBeOiYI1UhXpANryUouCirB-SDZPl-iv5CXmCuGeMN3UjH5MTISTPDvWGfLu8nSCFAcbZ9BRup4hLAho93YHp590dxcXuwc1Ib8K8ozAExBBHpD7FgRp6bZAOsIpNcvQG-i6M13RK0QHij_vvk0kz3W7fUhviEMcwx7QCOcDtskNYssnY0TG4L9A_JY-86RGeHd9T8vnd5aeLD8XVx_fbi_OrwpWymgvhlfBVK61nvm3aEpRVbV1Z7hmznTC-rFrVGS6F4qXwlllhK6WatmkU59bLU_Lq4Jvn_LoAzjqv5aDvzQhxQc1lJYSqW1Fl9OU_6D4uaczT6dVftlUpeKb4gXIpIibwespHNelOc6bXrvShK5270mtXWmXNi6PzYgfofit-lZOBsyNg0JneJzO6gH-4psrxrcicOHA4rbeF9NeI_03_CTeHrao</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>1328395421</pqid></control><display><type>article</type><title>Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel</title><source>MEDLINE</source><source>SpringerLink Journals</source><creator>Gube, Monika ; Brand, Peter ; Schettgen, Thomas ; Bertram, Jens ; Gerards, Kerstin ; Reisgen, Uwe ; Kraus, Thomas</creator><creatorcontrib>Gube, Monika ; Brand, Peter ; Schettgen, Thomas ; Bertram, Jens ; Gerards, Kerstin ; Reisgen, Uwe ; Kraus, Thomas</creatorcontrib><description>Objectives
The objective of this study was to investigate whether there is a relationship between the external exposure dose of chromium and nickel caused by a metal active gas welding process with a solid high-alloyed steel welding wire and inner exposure of subjects. In order to perform welding fume exposure under controlled and standardized conditions, the investigations were conducted in the “Aachen Workplace Simulation Laboratory”.
Methods
To perform biological monitoring of chromium and nickel, blood and urine samples of 12 healthy male non-smokers who never worked as welders were collected before and after a 6-h exposure to ambient air (0 mg/m
3
) and to welding fumes of a metal active gas welding process once with a concentration of the welding fume of 1 mg/m
3
and once with a concentration of 2.5 mg/m
3
.
Results
Although the internal exposure to chromium and nickel in this study was comparatively low, the subjects showed significantly increased concentrations of these metals in urine after exposure to welding fume compared to the values at baseline. Moreover, the observed increase was significantly dose dependent for both of the substances.
Conclusion
For the biological monitoring of chromium and nickel in urine of subjects exposed to welding fumes, a dependency on exposure dose was seen under standardized conditions after a single exposure over a period of 6 h. Thus, this study contributes to a better understanding of the relationship between ambient and biological exposures from welding fumes and provides a good basis for evaluating future biological threshold values for these metals in welding occupation.</description><identifier>ISSN: 0340-0131</identifier><identifier>EISSN: 1432-1246</identifier><identifier>DOI: 10.1007/s00420-012-0738-8</identifier><identifier>PMID: 22311006</identifier><identifier>CODEN: IAEHDW</identifier><language>eng</language><publisher>Berlin/Heidelberg: Springer-Verlag</publisher><subject>Biological and medical sciences ; Biomonitoring ; Case-Control Studies ; Chemical and industrial products toxicology. Toxic occupational diseases ; Chromium ; Chromium - blood ; Chromium - urine ; Cross-Over Studies ; Earth and Environmental Science ; Emissions ; Environment ; Environmental Health ; Environmental Monitoring - methods ; Fumes ; Gases ; Human exposure ; Humans ; Male ; Medical sciences ; Metal concentrations ; Metals ; Metals and various inorganic compounds ; Nickel ; Nickel - blood ; Nickel - urine ; Occupational Exposure ; Occupational medicine ; Occupational Medicine/Industrial Medicine ; Original Article ; Public health. Hygiene-occupational medicine ; Rehabilitation ; Toxicology ; Urine ; Welding</subject><ispartof>International archives of occupational and environmental health, 2013, Vol.86 (1), p.31-37</ispartof><rights>Springer-Verlag 2012</rights><rights>2014 INIST-CNRS</rights><rights>Springer-Verlag Berlin Heidelberg 2013</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c435t-2f82f593bf0f9794e8b8965b1f00bd2af4598da1328142fb0b2b5887977811bf3</citedby><cites>FETCH-LOGICAL-c435t-2f82f593bf0f9794e8b8965b1f00bd2af4598da1328142fb0b2b5887977811bf3</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://link.springer.com/content/pdf/10.1007/s00420-012-0738-8$$EPDF$$P50$$Gspringer$$H</linktopdf><linktohtml>$$Uhttps://link.springer.com/10.1007/s00420-012-0738-8$$EHTML$$P50$$Gspringer$$H</linktohtml><link.rule.ids>314,776,780,4010,27900,27901,27902,41464,42533,51294</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=27583992$$DView record in Pascal Francis$$Hfree_for_read</backlink><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/22311006$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Gube, Monika</creatorcontrib><creatorcontrib>Brand, Peter</creatorcontrib><creatorcontrib>Schettgen, Thomas</creatorcontrib><creatorcontrib>Bertram, Jens</creatorcontrib><creatorcontrib>Gerards, Kerstin</creatorcontrib><creatorcontrib>Reisgen, Uwe</creatorcontrib><creatorcontrib>Kraus, Thomas</creatorcontrib><title>Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel</title><title>International archives of occupational and environmental health</title><addtitle>Int Arch Occup Environ Health</addtitle><addtitle>Int Arch Occup Environ Health</addtitle><description>Objectives
The objective of this study was to investigate whether there is a relationship between the external exposure dose of chromium and nickel caused by a metal active gas welding process with a solid high-alloyed steel welding wire and inner exposure of subjects. In order to perform welding fume exposure under controlled and standardized conditions, the investigations were conducted in the “Aachen Workplace Simulation Laboratory”.
Methods
To perform biological monitoring of chromium and nickel, blood and urine samples of 12 healthy male non-smokers who never worked as welders were collected before and after a 6-h exposure to ambient air (0 mg/m
3
) and to welding fumes of a metal active gas welding process once with a concentration of the welding fume of 1 mg/m
3
and once with a concentration of 2.5 mg/m
3
.
Results
Although the internal exposure to chromium and nickel in this study was comparatively low, the subjects showed significantly increased concentrations of these metals in urine after exposure to welding fume compared to the values at baseline. Moreover, the observed increase was significantly dose dependent for both of the substances.
Conclusion
For the biological monitoring of chromium and nickel in urine of subjects exposed to welding fumes, a dependency on exposure dose was seen under standardized conditions after a single exposure over a period of 6 h. Thus, this study contributes to a better understanding of the relationship between ambient and biological exposures from welding fumes and provides a good basis for evaluating future biological threshold values for these metals in welding occupation.</description><subject>Biological and medical sciences</subject><subject>Biomonitoring</subject><subject>Case-Control Studies</subject><subject>Chemical and industrial products toxicology. Toxic occupational diseases</subject><subject>Chromium</subject><subject>Chromium - blood</subject><subject>Chromium - urine</subject><subject>Cross-Over Studies</subject><subject>Earth and Environmental Science</subject><subject>Emissions</subject><subject>Environment</subject><subject>Environmental Health</subject><subject>Environmental Monitoring - methods</subject><subject>Fumes</subject><subject>Gases</subject><subject>Human exposure</subject><subject>Humans</subject><subject>Male</subject><subject>Medical sciences</subject><subject>Metal concentrations</subject><subject>Metals</subject><subject>Metals and various inorganic compounds</subject><subject>Nickel</subject><subject>Nickel - blood</subject><subject>Nickel - urine</subject><subject>Occupational Exposure</subject><subject>Occupational medicine</subject><subject>Occupational Medicine/Industrial Medicine</subject><subject>Original Article</subject><subject>Public health. Hygiene-occupational medicine</subject><subject>Rehabilitation</subject><subject>Toxicology</subject><subject>Urine</subject><subject>Welding</subject><issn>0340-0131</issn><issn>1432-1246</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2013</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><sourceid>BENPR</sourceid><recordid>eNp1kc1u1DAUhS0EokPhAdggS6gSm4B_8uOwq6oCI1ViA2vLdq47HpI4-CZqu-sLsOMJeRIczfAjJFZe-Dvn3HsPIc85e80Za94gY6VgBeOiYI1UhXpANryUouCirB-SDZPl-iv5CXmCuGeMN3UjH5MTISTPDvWGfLu8nSCFAcbZ9BRup4hLAho93YHp590dxcXuwc1Ib8K8ozAExBBHpD7FgRp6bZAOsIpNcvQG-i6M13RK0QHij_vvk0kz3W7fUhviEMcwx7QCOcDtskNYssnY0TG4L9A_JY-86RGeHd9T8vnd5aeLD8XVx_fbi_OrwpWymgvhlfBVK61nvm3aEpRVbV1Z7hmznTC-rFrVGS6F4qXwlllhK6WatmkU59bLU_Lq4Jvn_LoAzjqv5aDvzQhxQc1lJYSqW1Fl9OU_6D4uaczT6dVftlUpeKb4gXIpIibwespHNelOc6bXrvShK5270mtXWmXNi6PzYgfofit-lZOBsyNg0JneJzO6gH-4psrxrcicOHA4rbeF9NeI_03_CTeHrao</recordid><startdate>2013</startdate><enddate>2013</enddate><creator>Gube, Monika</creator><creator>Brand, Peter</creator><creator>Schettgen, Thomas</creator><creator>Bertram, Jens</creator><creator>Gerards, Kerstin</creator><creator>Reisgen, Uwe</creator><creator>Kraus, Thomas</creator><general>Springer-Verlag</general><general>Springer</general><general>Springer Nature B.V</general><scope>IQODW</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>3V.</scope><scope>7T2</scope><scope>7T5</scope><scope>7TM</scope><scope>7U7</scope><scope>7X7</scope><scope>7XB</scope><scope>88E</scope><scope>88I</scope><scope>8AO</scope><scope>8C1</scope><scope>8FI</scope><scope>8FJ</scope><scope>8FK</scope><scope>ABUWG</scope><scope>AEUYN</scope><scope>AFKRA</scope><scope>ATCPS</scope><scope>AZQEC</scope><scope>BENPR</scope><scope>BHPHI</scope><scope>C1K</scope><scope>CCPQU</scope><scope>DWQXO</scope><scope>FYUFA</scope><scope>GHDGH</scope><scope>GNUQQ</scope><scope>H94</scope><scope>HCIFZ</scope><scope>K9.</scope><scope>M0S</scope><scope>M1P</scope><scope>M2P</scope><scope>PATMY</scope><scope>PQEST</scope><scope>PQQKQ</scope><scope>PQUKI</scope><scope>PYCSY</scope><scope>Q9U</scope><scope>7U2</scope></search><sort><creationdate>2013</creationdate><title>Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel</title><author>Gube, Monika ; Brand, Peter ; Schettgen, Thomas ; Bertram, Jens ; Gerards, Kerstin ; Reisgen, Uwe ; Kraus, Thomas</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c435t-2f82f593bf0f9794e8b8965b1f00bd2af4598da1328142fb0b2b5887977811bf3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2013</creationdate><topic>Biological and medical sciences</topic><topic>Biomonitoring</topic><topic>Case-Control Studies</topic><topic>Chemical and industrial products toxicology. Toxic occupational diseases</topic><topic>Chromium</topic><topic>Chromium - blood</topic><topic>Chromium - urine</topic><topic>Cross-Over Studies</topic><topic>Earth and Environmental Science</topic><topic>Emissions</topic><topic>Environment</topic><topic>Environmental Health</topic><topic>Environmental Monitoring - methods</topic><topic>Fumes</topic><topic>Gases</topic><topic>Human exposure</topic><topic>Humans</topic><topic>Male</topic><topic>Medical sciences</topic><topic>Metal concentrations</topic><topic>Metals</topic><topic>Metals and various inorganic compounds</topic><topic>Nickel</topic><topic>Nickel - blood</topic><topic>Nickel - urine</topic><topic>Occupational Exposure</topic><topic>Occupational medicine</topic><topic>Occupational Medicine/Industrial Medicine</topic><topic>Original Article</topic><topic>Public health. Hygiene-occupational medicine</topic><topic>Rehabilitation</topic><topic>Toxicology</topic><topic>Urine</topic><topic>Welding</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Gube, Monika</creatorcontrib><creatorcontrib>Brand, Peter</creatorcontrib><creatorcontrib>Schettgen, Thomas</creatorcontrib><creatorcontrib>Bertram, Jens</creatorcontrib><creatorcontrib>Gerards, Kerstin</creatorcontrib><creatorcontrib>Reisgen, Uwe</creatorcontrib><creatorcontrib>Kraus, Thomas</creatorcontrib><collection>Pascal-Francis</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>ProQuest Central (Corporate)</collection><collection>Health and Safety Science Abstracts (Full archive)</collection><collection>Immunology Abstracts</collection><collection>Nucleic Acids Abstracts</collection><collection>Toxicology Abstracts</collection><collection>Health & Medical Collection</collection><collection>ProQuest Central (purchase pre-March 2016)</collection><collection>Medical Database (Alumni Edition)</collection><collection>Science Database (Alumni Edition)</collection><collection>ProQuest Pharma Collection</collection><collection>Public Health Database</collection><collection>Hospital Premium Collection</collection><collection>Hospital Premium Collection (Alumni Edition)</collection><collection>ProQuest Central (Alumni) (purchase pre-March 2016)</collection><collection>ProQuest Central (Alumni Edition)</collection><collection>ProQuest One Sustainability</collection><collection>ProQuest Central UK/Ireland</collection><collection>Agricultural & Environmental Science Collection</collection><collection>ProQuest Central Essentials</collection><collection>ProQuest Central</collection><collection>Natural Science Collection</collection><collection>Environmental Sciences and Pollution Management</collection><collection>ProQuest One Community College</collection><collection>ProQuest Central Korea</collection><collection>Health Research Premium Collection</collection><collection>Health Research Premium Collection (Alumni)</collection><collection>ProQuest Central Student</collection><collection>AIDS and Cancer Research Abstracts</collection><collection>SciTech Premium Collection</collection><collection>ProQuest Health & Medical Complete (Alumni)</collection><collection>Health & Medical Collection (Alumni Edition)</collection><collection>Medical Database</collection><collection>Science Database</collection><collection>Environmental Science Database</collection><collection>ProQuest One Academic Eastern Edition (DO NOT USE)</collection><collection>ProQuest One Academic</collection><collection>ProQuest One Academic UKI Edition</collection><collection>Environmental Science Collection</collection><collection>ProQuest Central Basic</collection><collection>Safety Science and Risk</collection><jtitle>International archives of occupational and environmental health</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Gube, Monika</au><au>Brand, Peter</au><au>Schettgen, Thomas</au><au>Bertram, Jens</au><au>Gerards, Kerstin</au><au>Reisgen, Uwe</au><au>Kraus, Thomas</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel</atitle><jtitle>International archives of occupational and environmental health</jtitle><stitle>Int Arch Occup Environ Health</stitle><addtitle>Int Arch Occup Environ Health</addtitle><date>2013</date><risdate>2013</risdate><volume>86</volume><issue>1</issue><spage>31</spage><epage>37</epage><pages>31-37</pages><issn>0340-0131</issn><eissn>1432-1246</eissn><coden>IAEHDW</coden><abstract>Objectives
The objective of this study was to investigate whether there is a relationship between the external exposure dose of chromium and nickel caused by a metal active gas welding process with a solid high-alloyed steel welding wire and inner exposure of subjects. In order to perform welding fume exposure under controlled and standardized conditions, the investigations were conducted in the “Aachen Workplace Simulation Laboratory”.
Methods
To perform biological monitoring of chromium and nickel, blood and urine samples of 12 healthy male non-smokers who never worked as welders were collected before and after a 6-h exposure to ambient air (0 mg/m
3
) and to welding fumes of a metal active gas welding process once with a concentration of the welding fume of 1 mg/m
3
and once with a concentration of 2.5 mg/m
3
.
Results
Although the internal exposure to chromium and nickel in this study was comparatively low, the subjects showed significantly increased concentrations of these metals in urine after exposure to welding fume compared to the values at baseline. Moreover, the observed increase was significantly dose dependent for both of the substances.
Conclusion
For the biological monitoring of chromium and nickel in urine of subjects exposed to welding fumes, a dependency on exposure dose was seen under standardized conditions after a single exposure over a period of 6 h. Thus, this study contributes to a better understanding of the relationship between ambient and biological exposures from welding fumes and provides a good basis for evaluating future biological threshold values for these metals in welding occupation.</abstract><cop>Berlin/Heidelberg</cop><pub>Springer-Verlag</pub><pmid>22311006</pmid><doi>10.1007/s00420-012-0738-8</doi><tpages>7</tpages></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0340-0131 |
| ispartof | International archives of occupational and environmental health, 2013, Vol.86 (1), p.31-37 |
| issn | 0340-0131 1432-1246 |
| language | eng |
| recordid | cdi_proquest_miscellaneous_1352286925 |
| source | MEDLINE; SpringerLink Journals |
| subjects | Biological and medical sciences Biomonitoring Case-Control Studies Chemical and industrial products toxicology. Toxic occupational diseases Chromium Chromium - blood Chromium - urine Cross-Over Studies Earth and Environmental Science Emissions Environment Environmental Health Environmental Monitoring - methods Fumes Gases Human exposure Humans Male Medical sciences Metal concentrations Metals Metals and various inorganic compounds Nickel Nickel - blood Nickel - urine Occupational Exposure Occupational medicine Occupational Medicine/Industrial Medicine Original Article Public health. Hygiene-occupational medicine Rehabilitation Toxicology Urine Welding |
| title | Experimental exposure of healthy subjects with emissions from a gas metal arc welding process—part II: biomonitoring of chromium and nickel |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-02-06T23%3A13%3A48IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Experimental%20exposure%20of%20healthy%20subjects%20with%20emissions%20from%20a%20gas%20metal%20arc%20welding%20process%E2%80%94part%20II:%20biomonitoring%20of%20chromium%20and%20nickel&rft.jtitle=International%20archives%20of%20occupational%20and%20environmental%20health&rft.au=Gube,%20Monika&rft.date=2013&rft.volume=86&rft.issue=1&rft.spage=31&rft.epage=37&rft.pages=31-37&rft.issn=0340-0131&rft.eissn=1432-1246&rft.coden=IAEHDW&rft_id=info:doi/10.1007/s00420-012-0738-8&rft_dat=%3Cproquest_cross%3E1352286925%3C/proquest_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=1328395421&rft_id=info:pmid/22311006&rfr_iscdi=true |