{"id":3513,"date":"2019-11-29T07:34:26","date_gmt":"2019-11-29T06:34:26","guid":{"rendered":"http:\/\/potravinyx.cz\/?p=3513"},"modified":"2019-11-29T07:34:28","modified_gmt":"2019-11-29T06:34:28","slug":"laboratorne-nebylo-prokazano-poskozeni-strevni-tkane-polystyrenovymi-mikroplasty","status":"publish","type":"post","link":"https:\/\/potravinyx.cz\/?p=3513","title":{"rendered":"Laboratorn\u011b nebylo prok\u00e1z\u00e1no po\u0161kozen\u00ed st\u0159evn\u00ed tk\u00e1n\u011b polystyrenov\u00fdmi mikroplasty"},"content":{"rendered":"\n

<\/p>\n\n\n\n

V\u011bdci Spolkov\u00e9ho \u00fa\u0159adu pro hodnocen\u00ed rizik (BfR) nena\u0161li \u017e\u00e1dn\u00e9 d\u016fkazy po\u0161kozen\u00ed st\u0159evn\u00ed tk\u00e1n\u011b (jako je oxidativn\u00ed stres nebo zn\u00e1mky z\u00e1n\u011btu), kter\u00e9 by zp\u016fsobily polystyrenov\u00e9 (PS) mikroplastov\u00e9 \u010d\u00e1stice. Toto je jedno z nejd\u016fle\u017eit\u011bj\u0161\u00edch zji\u0161t\u011bn\u00ed na z\u00e1klad\u011b laboratorn\u00edch experiment\u016f.<\/p>\n\n\n\n

Polystyren (PS) je jedn\u00edm z nejpou\u017e\u00edvan\u011bj\u0161\u00edch plast\u016f na sv\u011bt\u011b. Je pou\u017e\u00edv\u00e1n mimo jin\u00e9 k v\u00fdrob\u011b potravin\u00e1\u0159sk\u00fdch obal\u016f a b\u011b\u017en\u00fdch p\u0159edm\u011bt\u016f, jako jsou cyklistick\u00e9 helmy. Mikroplasty jsou mal\u00e9 plastov\u00e9 \u010d\u00e1stice a vl\u00e1kna, kter\u00e1 jsou v prost\u0159ed\u00ed detekov\u00e1na st\u00e1le \u010dast\u011bji. Po\u010d\u00e1te\u010dn\u00ed v\u011bdeck\u00e9 anal\u00fdzy ukazuj\u00ed, \u017ee lid\u00e9 tak\u00e9 mikroplasty prost\u0159ednictv\u00edm sv\u00e9 stravy konzumuj\u00ed.<\/p>\n\n\n\n

C\u00edlem studie BfR proto bylo zji\u0161t\u011bn\u00ed p\u0159\u00edjmu a \u00fa\u010dink\u016f polystyrenov\u00fdch mikroplast\u016f. Jeliko\u017e k vyhodnocen\u00ed potenci\u00e1ln\u00edch \u00fa\u010dink\u016f mikroplast\u016f byly k dispozici pouze omezen\u00e9 \u00fadaje, bylo d\u016fle\u017eit\u00e9 z\u00edskat nov\u00e1 data. V\u011bdci z BfR k tomu vyu\u017eili dv\u011b metody. Jednou z nich bylo pou\u017eit\u00ed lidsk\u00fdch bun\u011b\u010dn\u00fdch lini\u00ed st\u0159evn\u00edch epiteli\u00e1ln\u00edch bun\u011bk (in vitro) ke zkoum\u00e1n\u00ed mo\u017en\u00e9 absorpce PS mikroplastov\u00fdch \u010d\u00e1stic r\u016fzn\u00fdch velikost\u00ed (jeden, \u010dty\u0159i a deset \u00b5m v pr\u016fm\u011bru) a posouzen\u00ed, zda mohou b\u00fdt absorbov\u00e1ny t\u011bmito bu\u0148kami. Druhou metodou bylo pod\u00e1v\u00e1n\u00ed krmiva s t\u011bmito PS mikroplasty my\u0161\u00edm (in vivo) po dobu 28 dn\u016f za \u00fa\u010delem zkoum\u00e1n\u00ed transportu mikroplastov\u00fdch \u010d\u00e1stic do st\u0159eva a n\u00e1sledn\u00e9 odpov\u011bdi st\u0159evn\u00edch bun\u011bk na tyto \u010d\u00e1stice.<\/p>\n\n\n\n

Pokusy s bun\u011b\u010dn\u00fdmi liniemi uk\u00e1zaly, \u017ee PS \u010d\u00e1stice a\u017e do pr\u016fm\u011bru asi 4 \u00b5m mohou b\u00fdt skute\u010dn\u011b absorbov\u00e1ny epiteli\u00e1ln\u00edmi bu\u0148kami st\u0159evn\u00ed st\u011bny. P\u0159i pokusech na zv\u00ed\u0159atech v\u0161ak bylo zji\u0161t\u011bno, \u017ee i p\u0159es pod\u00e1v\u00e1n\u00ed velk\u00fdch mno\u017estv\u00ed plastov\u00fdch \u010d\u00e1stic o velikosti od 1 do 10 \u00b5m, bylo mo\u017en\u00e9 mikro\u010d\u00e1stice ve zkouman\u00fdch st\u0159evn\u00edch epiteli\u00e1ln\u00edch bu\u0148k\u00e1ch detekovat pouze sporadicky. Pod\u00e1van\u00e1 mno\u017estv\u00ed mikroplast\u016f byla mnohem vy\u0161\u0161\u00ed ne\u017e ta, kter\u00e1 jsou pro \u010dlov\u011bka re\u00e1ln\u00e1. Ve st\u0159evn\u00ed tk\u00e1ni ani v jin\u00fdch org\u00e1nech my\u0161\u00ed nebyly pozorov\u00e1ny \u017e\u00e1dn\u00e9 \u0161kodliv\u00e9 \u00fa\u010dinky.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

V\u011bdci ale otev\u0159en\u011b poukazuj\u00ed na to, \u017ee je p\u0159\u00edli\u0161 m\u00e1lo dat vztahuj\u00edc\u00edch se k velikosti a materi\u00e1lu mikroplast\u016f. Z generovan\u00fdch dat nap\u0159\u00edklad nelze vyvodit \u017e\u00e1dn\u00e9 z\u00e1v\u011bry o \u00fa\u010dinc\u00edch mikroplast\u016f ve st\u0159ev\u011b, pokud by byly z jin\u00e9ho materi\u00e1lu (plastu). K anal\u00fdze p\u0159\u00edjmu mikroplast\u016f a posouzen\u00ed s t\u00edm souvisej\u00edc\u00edch rizik jsou proto nezbytn\u00e9 dal\u0161\u00ed experiment\u00e1ln\u00ed studie. <\/p>\n\n\n\n

Autorka p\u0159ekladu: Ing. Nikol Modr\u00e1\u010dkov\u00e1, \u010cZU v Praze<\/p>\n\n\n\n

V\u00fdsledky studie na zv\u00ed\u0159atech byly zve\u0159ejn\u011bny v \u010dasopise Archives of Toxicology:
<\/a>https:\/\/link.springer.com\/article\/10.1007\/s00204-019-02478-7<\/a><\/p>\n\n\n\n

Dal\u0161\u00ed informace k tomuto t\u00e9matu jsou dostupn\u00e9 na webov\u00fdch str\u00e1nk\u00e1ch BfR \u2026
Ot\u00e1zky a odpov\u011bdi o mikroplastech:
https:\/\/www.bfr.bund.de\/en\/microplastics__facts__research_and_open_questions-192775.html<\/a><\/p>\n\n\n\n

\u010cl\u00e1nek p\u0159evzat z bezpecnostpotravin.cz<\/p>\n","protected":false},"excerpt":{"rendered":"

V\u011bdci Spolkov\u00e9ho \u00fa\u0159adu pro hodnocen\u00ed rizik (BfR) nena\u0161li \u017e\u00e1dn\u00e9 d\u016fkazy po\u0161kozen\u00ed st\u0159evn\u00ed tk\u00e1n\u011b (jako je oxidativn\u00ed stres nebo zn\u00e1mky z\u00e1n\u011btu), kter\u00e9 by zp\u016fsobily polystyrenov\u00e9 (PS) mikroplastov\u00e9 \u010d\u00e1stice. Toto je jedno z nejd\u016fle\u017eit\u011bj\u0161\u00edch zji\u0161t\u011bn\u00ed na z\u00e1klad\u011b [v\u00edc]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":3514,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[335,336,338,337,122],"class_list":["post-3513","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-kontrola-potravin","tag-mikroplasty","tag-obaly","tag-riziko","tag-strava","tag-zdravi"],"views":2358,"_links":{"self":[{"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/posts\/3513","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3513"}],"version-history":[{"count":0,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/posts\/3513\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=\/wp\/v2\/media\/3514"}],"wp:attachment":[{"href":"https:\/\/potravinyx.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3513"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3513"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/potravinyx.cz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3513"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}