摘要 微塑料是一種新興污染物,塑料制品的廣泛使用和處理不當(dāng)對(duì)土壤生態(tài)系統(tǒng)構(gòu)成了潛在的環(huán)境風(fēng)險(xiǎn)。微塑料在土壤中為微生物提供了新的棲息地,并與周?chē)h(huán)境形成了一個(gè)獨(dú)特的生態(tài)系統(tǒng)——塑料際。塑料在土壤環(huán)境中不易降解,使得塑料際對(duì)原始土壤環(huán)境造成了嚴(yán)重且持久的生態(tài)威脅。目前對(duì)塑料際的研究主要集中在水生生態(tài)系統(tǒng),關(guān)于土壤塑料際對(duì)微生物、微塑料以及土壤環(huán)境和其他污染物的影響聯(lián)合效應(yīng)等方面的認(rèn)識(shí)仍然非常有限。為探究土壤塑料際中微生物與微塑料相互作用的機(jī)制和隨之產(chǎn)生的生態(tài)效應(yīng),本文綜述了塑料際作為土壤微生物新的棲息地帶來(lái)的生態(tài)風(fēng)險(xiǎn)相關(guān)研究進(jìn)展,主要討論了土壤塑料際對(duì)微生物的選擇效應(yīng)與微塑料遷移轉(zhuǎn)化的影響、土壤塑料際對(duì)土壤結(jié)構(gòu)與土壤碳循環(huán)帶來(lái)的改變以及與其他環(huán)境污染物的聯(lián)合效應(yīng)。
關(guān)鍵詞 塑料際; 微塑料; 微生物; 土壤環(huán)境; 環(huán)境污染物; 遷移轉(zhuǎn)化; 生態(tài)風(fēng)險(xiǎn); 碳循環(huán)
中圖分類(lèi)號(hào) X171 文獻(xiàn)標(biāo)識(shí)碼 A 文章編號(hào) 1000-2421(2024)04-0102-10
塑料污染正在成為環(huán)境科學(xué)的一個(gè)重要問(wèn)題[1],由于塑料制品的大量生產(chǎn)和利用,微塑料廣泛存在于海洋、河流、土壤、大氣等各種自然環(huán)境中[2-4],甚至在北極等偏遠(yuǎn)的生態(tài)系統(tǒng)也是如此。微塑料是指最大粒徑小于5 mm 的塑料顆粒[5],通過(guò)大氣沉降和農(nóng)業(yè)活動(dòng)等多種途徑進(jìn)入生態(tài)系統(tǒng)。它被認(rèn)為是一種具有全球意義的新興污染物并成為影響全球環(huán)境變化的因素之一[6]。根據(jù)1950-2015 年全球塑料制造、消費(fèi)和末端處置的數(shù)據(jù),全球塑料垃圾總量約為63 億t,但是只有9% 的塑料垃圾被回收利用,79%的塑料垃圾堆積在垃圾填埋場(chǎng)或自然環(huán)境中[7]。研究表明,陸地上的微塑料可能是海洋中的4~23倍[8]。這些不易降解的微塑料在土壤生態(tài)系統(tǒng)中不斷積累,已經(jīng)對(duì)動(dòng)植物和土壤特性造成嚴(yán)重的影響,更小尺寸的塑料顆粒還會(huì)被土壤生物吸收并隨著食物鏈富集,危害人體健康。目前,微塑料對(duì)土壤特性和動(dòng)植物的影響已被廣泛研究[9-11],而微塑料對(duì)土壤微生物群落的影響研究仍有限。
“塑料際(plastisphere)”一詞最早由Zettler 等[12]于2013 年提出。隨著土壤中塑料際研究的深入,塑料際的定義已經(jīng)不僅限于水生環(huán)境中棲息著的微生物群落中的塑料顆粒。雖然一些學(xué)者仍然采用最初針對(duì)水生環(huán)境的塑料際定義,但也有研究人員針對(duì)塑料表面提出了棲息地或生態(tài)位的概念,從而出現(xiàn)了“塑料際微生物組”或“塑料際微生物群落”等術(shù)語(yǔ)[13]。這些術(shù)語(yǔ)表明,塑料際不僅限于塑料表面上的微生物,還包括存在于土壤中受塑料影響的微生物。塑料中化學(xué)物質(zhì)的浸出改變了周?chē)沫h(huán)境,而在土壤的固體基質(zhì)中的變化比在水中更為普遍。因此,陸地生態(tài)系統(tǒng)塑料際不同于生物膜,還包括了它周?chē)奈h(huán)境[1]。
微塑料由于其獨(dú)特的物理化學(xué)性質(zhì),具有強(qiáng)大的攜帶環(huán)境物質(zhì)和微生物的能力,并促進(jìn)生物膜形成,因此,微塑料能與其接觸的微環(huán)境構(gòu)成一個(gè)特殊的微生態(tài)系統(tǒng)——塑料際[12]。塑料際中的微生物包括細(xì)菌、藻類(lèi)和其他單細(xì)胞生物,其中很多生物還在不斷快速進(jìn)化以適應(yīng)塑料環(huán)境[1]。獨(dú)特的化學(xué)性質(zhì)和緩慢的生物降解速率,使塑料區(qū)別于其他自然生成的物質(zhì)。超過(guò)1 000 種的微生物可以棲息在1 塊直徑5 mm 的微塑料上,微塑料還可以作為這些生物長(zhǎng)距離運(yùn)輸?shù)拿浇椋肭治锓N有可能借此引入到本地的生態(tài)系統(tǒng)中[14]。
土壤塑料際的形成和演替可由微塑料特征和土壤環(huán)境因子共同驅(qū)動(dòng)[15]。局部環(huán)境條件(如光照、鹽度、溫度、營(yíng)養(yǎng)狀況和水動(dòng)力條件等)和地理、空間和時(shí)間因素可能在很大程度上影響環(huán)境中塑料際生物群落的形成和演替[16]。同樣,土壤環(huán)境因素(如土壤性質(zhì)和氣候條件)和微塑料特征(如聚合物類(lèi)型、形狀、大小和表面性質(zhì))也可能影響土壤塑料際[15]。近期的一項(xiàng)研究表明,微塑料(貢獻(xiàn)27%)和土壤(貢獻(xiàn)21%)顯著促進(jìn)了土壤塑料際細(xì)菌群落的分化[17]。因此,探究微塑料污染對(duì)土壤微生物群落的影響及其帶來(lái)的土壤生態(tài)風(fēng)險(xiǎn)具有重要意義。
以往的研究主要集中在微塑料對(duì)土壤生態(tài)系統(tǒng)的影響上[18],而對(duì)微塑料與其周?chē)寥牢h(huán)境形成的獨(dú)特生態(tài)系統(tǒng)——塑料際的研究較少。且塑料際在土壤生態(tài)系統(tǒng)中的影響因素及生態(tài)效應(yīng)的研究還不夠深入。因此,本文以塑料際為核心,闡述了塑料際對(duì)土壤微生物群落、微塑料和其他污染物帶來(lái)的不同影響以及隨之產(chǎn)生的相關(guān)生態(tài)風(fēng)險(xiǎn)。
1 土壤塑料際微生物群落的選擇效應(yīng)
在土壤生態(tài)系統(tǒng)中,塑料類(lèi)型對(duì)塑料際中土壤微生物的種類(lèi)有顯著影響,不同類(lèi)型塑料際中的微生物存在差異,這些差異大多是由于不同塑料類(lèi)型帶來(lái)的選擇作用[19]。不同塑料表面的微生物組成和優(yōu)勢(shì)種類(lèi)隨著時(shí)間、塑料性能以及生物和非生物環(huán)境因素的變化而發(fā)生較大變化[20]。例如,與土壤環(huán)境相比,塑料際細(xì)菌群落的α 多樣性較低,放線菌(Actinobacteria)的豐度增加[21]。在陸生環(huán)境中,叢赤殼科(Nectriaceae)、枝孢菌科(Cladosporiaceae)和格孢腔菌科(Pleosporaceae)細(xì)菌在聚己二酸/對(duì)苯二甲酸丁二酯和聚乳酸等可生物降解微塑料中的豐度更高,而麥角科(Clavicipitaceae)細(xì)菌在聚乙烯上的豐度更高。在2 種不同土壤環(huán)境中,變形桿菌(Pro?teobacteria)、放線菌(Actinobacteria)和擬桿菌屬(Bacteroides)在聚乳酸、聚己二酸/對(duì)苯二甲酸丁二酯和聚乙烯上的豐度不同[22]。微塑料顏色對(duì)相關(guān)塑料際的微生物組成也有影響,其中綠彎菌門(mén)(Chloroflexi)在黃色和透明微塑料上富集,而硬壁菌門(mén)(Firmicutes)在藍(lán)色微塑料上富集。這種微生物群落的差異可歸因于微塑料反射光波長(zhǎng)的不同[23]。難降解微塑料之間的微生物組成也存在顯著差異,例如,聚苯乙烯微塑料上的微生物群與聚乙烯和聚丙烯上的微生物群存在很大差異[24]。除此之外,塑料際環(huán)境條件對(duì)真核生物群落組成的影響比原核生物更大[25]。
微塑料的物理化學(xué)特性也是影響塑料際微生物選擇性的因素[26]。微塑料粒徑、表面粗糙度、疏水性、表面自由能和比表面積等特性的不同,會(huì)影響塑料際微生物群落的結(jié)構(gòu)組成。例如,微塑料的疏水性會(huì)對(duì)微生物定殖及其胞外酶活性產(chǎn)生影響。細(xì)菌會(huì)優(yōu)先在更親水的表面上定殖[27],這可能是由于親水表面的潤(rùn)濕性和表面能更高。此外,微塑料的表面粗糙度越大,意味著微生物可以獲得更多的附著點(diǎn),從而影響塑料際早期的微生物群落組成[28]。不同的塑料帶有不同的表面電荷,這可能導(dǎo)致微塑料對(duì)微生物的吸附作用存在差異[29]。具有特定結(jié)構(gòu)的細(xì)菌可以更容易地克服帶負(fù)電荷的細(xì)胞與塑料表面之間的排斥力,因此,能夠更好地在某些塑料表面定殖。隨著時(shí)間的推移,由于暴露在陽(yáng)光、氧氣和其他環(huán)境因子下,生態(tài)系統(tǒng)中微塑料的自然老化和風(fēng)化過(guò)程會(huì)使微塑料的聚合物鏈斷裂從而增加其表面粗糙度、比表面積、親水性和含氧官能團(tuán)。這種老化過(guò)程改變了微塑料的表面特性,從而改變了塑料際的結(jié)構(gòu)[30]。研究表明,光老化后的微塑料會(huì)影響塑料際內(nèi)的細(xì)菌組成,使塑料際中的微生物生物量減少,從而降低了塑料際內(nèi)微生物網(wǎng)絡(luò)的復(fù)雜性和穩(wěn)定性。老化還會(huì)使塑料際內(nèi)細(xì)菌群落的碳代謝能力增強(qiáng),因此,具有更高碳利用能力的微生物會(huì)附著在老化微塑料上[31]。綜上,微塑料表面特性、聚合物特性和環(huán)境因素在塑料際微生物群落的演替中起著關(guān)鍵作用(表1)。
2 土壤微生物對(duì)微塑料在土壤生態(tài)系統(tǒng)中的遷移轉(zhuǎn)化作用
塑料際微生物在塑料風(fēng)化和破碎過(guò)程中起著至關(guān)重要的作用。在土壤中,塑料降解是一個(gè)結(jié)合了非生物(光氧化、熱氧化或聚酯的水解)和生物(酶促解聚、礦化和同化)降解過(guò)程的綜合反應(yīng)[35]。這些過(guò)程會(huì)使塑料的理化性質(zhì)(相對(duì)分子質(zhì)量、機(jī)械性能、結(jié)晶度、黏度和官能團(tuán))發(fā)生改變[36]。塑料的風(fēng)化沿著2 條相互關(guān)聯(lián)且協(xié)同的路徑進(jìn)行,碎裂和可溶性或揮發(fā)性成分的釋放與生物污損和氧化降解過(guò)程相結(jié)合[37]。塑料生物降解中涉及的不同生化降解途徑可分為生物降解、生物破碎、同化和礦化,所有這些生化過(guò)程都是通過(guò)各種酶促反應(yīng)、化學(xué)鍵斷裂來(lái)實(shí)現(xiàn)的[38]。
雖然土壤微生物對(duì)塑料的生物降解是一個(gè)相對(duì)緩慢的過(guò)程(通常需要100 a 以上才能完成),但微生物在土壤塑料上的短期定殖會(huì)導(dǎo)致塑料的理化性質(zhì)尤其是塑料的尺寸發(fā)生巨大變化[39]。在這一過(guò)程中,土壤微生物分泌的胞外酶將大分子聚合物分解成較小的產(chǎn)物,這些產(chǎn)物隨后可以被微生物代謝[40]。塑料際微生物群落可能是導(dǎo)致微塑料斷裂和產(chǎn)生一系列短鏈碎片(即低聚物、二聚體和單體)的關(guān)鍵驅(qū)動(dòng)力。土壤微生物附著在微塑料表面后,胞外酶就有機(jī)會(huì)作用于聚合物骨架。在可水解點(diǎn)(聚合物的酯鍵和氨基鍵等)通過(guò)特定的水解酶進(jìn)行裂解[41]。在一些不可水解點(diǎn)(如結(jié)晶固體、疏水區(qū)域和強(qiáng)C-C骨架),塑料裂解需要依賴(lài)其他因素,如光、熱或化學(xué)作用[42]。當(dāng)好氧微生物將氧氣耗盡后,小分子有機(jī)酸、硫酸鹽等可作為替代氧氣的電子受體,進(jìn)入緩慢的厭氧生物降解過(guò)程。解聚后,部分微生物細(xì)胞可能會(huì)吸收一些短鏈(通常為10~50 個(gè)C)聚合物或較小的分子(低聚物和單體)進(jìn)行進(jìn)一步的代謝[43]。更小的納米塑料還可能涉及到比微塑料更加復(fù)雜的生物降解過(guò)程。有研究表明,如果納米顆粒足夠?。╨t;100 nm),它們可以通過(guò)內(nèi)吞作用或裂縫模式進(jìn)入動(dòng)物細(xì)胞或植物組織[44]。小分子可以穿過(guò)半透膜,作為碳源或能量來(lái)源,被胞內(nèi)酶礦化為無(wú)機(jī)產(chǎn)物,如好氧時(shí)的CO2 和厭氧時(shí)的CH4[45]。在多孔介質(zhì)中,較小塑料比較大塑料更容易遷移[46]。當(dāng)亞微米級(jí)或納米級(jí)顆粒形成后,它們會(huì)以膠體的形式進(jìn)行遷移,并在地下水環(huán)境中快速遷移沉積[47]。這種遷移方式增加了地下水污染的風(fēng)險(xiǎn),從而威脅到飲用水安全。已經(jīng)有研究發(fā)現(xiàn),地下水中存在20 μm 的塑料顆粒[48]??紤]到地下水是人類(lèi)重要的飲用水源之一,進(jìn)一步探究地下水中是否存在亞微米級(jí)和納米級(jí)塑料顆粒是有必要的。
綜上,塑料際微生物對(duì)微塑料的一系列生物化學(xué)作用,促進(jìn)了微塑料在土壤生態(tài)系統(tǒng)中的遷移轉(zhuǎn)化,間接增強(qiáng)了微塑料在土壤環(huán)境中的生態(tài)毒性,對(duì)土壤動(dòng)植物生長(zhǎng)和生理過(guò)程造成嚴(yán)重影響,進(jìn)而使土壤生態(tài)環(huán)境發(fā)生改變。
3 土壤塑料際的生態(tài)效應(yīng)
3.1 微塑料對(duì)土壤結(jié)構(gòu)的影響
土壤中微塑料的存在會(huì)擾亂土壤原有的物理參數(shù),如改變土壤結(jié)構(gòu),影響土壤容重、水分蒸發(fā)以及水分有效性。微塑料對(duì)土壤結(jié)構(gòu)的影響取決于微塑料的形狀、類(lèi)型、尺寸和濃度[49]。例如,與塑料顆粒相比,塑料纖維對(duì)土壤性質(zhì)的影響更為明顯[10]。土壤容重作為土壤侵蝕風(fēng)險(xiǎn)評(píng)價(jià)指標(biāo)[50],會(huì)因微塑料類(lèi)型和測(cè)試土樣的密度不同而改變[10]。微塑料也會(huì)改變土壤孔隙度,因?yàn)槲⑺芰蠚埩粑锘蛩槠瑫?huì)破壞土壤孔隙連續(xù)性,使得顆?;蚍勰└菀滋畛渫寥揽紫兜目臻g[51]。土壤孔隙的變化又會(huì)影響水分循環(huán)要素,如蒸發(fā)、重力運(yùn)動(dòng)和土壤孔隙水含量[52]。由于土壤孔隙度和水循環(huán)的改變,土壤中氣體通量也會(huì)受到影響,從而進(jìn)一步影響土壤中厭氧或好氧微生物的豐度[53]。某些特定類(lèi)型的微塑料還會(huì)影響土壤的聚集,這是塑造土壤微生物棲息地與土壤結(jié)構(gòu)的關(guān)鍵過(guò)程。盡管目前對(duì)這種影響的潛在機(jī)制知之甚少,但一些研究已經(jīng)證明,微塑料纖維對(duì)土壤團(tuán)聚體的影響最為顯著[10]。微塑料不會(huì)影響土壤團(tuán)聚體的穩(wěn)定性,但微塑料纖維會(huì)使較小的土壤團(tuán)聚體聚集在一起,從而增加了大土壤團(tuán)聚體的比例[54]。因此,微塑料對(duì)土壤聚集的影響會(huì)改變土壤孔隙度,影響土壤水分循環(huán)和氣體通量,以及相關(guān)土壤微生物群落。土壤團(tuán)聚體的保護(hù)作用可以防止土壤有機(jī)質(zhì)快速分解,穩(wěn)定的土壤團(tuán)聚體還會(huì)使土壤有機(jī)碳固定并增加。研究發(fā)現(xiàn),土壤有機(jī)碳含量會(huì)影響塑料際與周?chē)寥赖奈⑸锶郝洳町惓潭?,并與之呈負(fù)相關(guān)關(guān)系[55]。因此,微塑料通過(guò)改變土壤物理性質(zhì)影響微生物棲息地的生化環(huán)境,進(jìn)而導(dǎo)致微生物群落發(fā)生變化。
3.2 微塑料對(duì)土壤碳循環(huán)的影響
微塑料導(dǎo)致的土壤性質(zhì)和微生物變化會(huì)影響土壤碳的生物地球化學(xué)循環(huán)[56]。微塑料聚合單元中含有約80% 的碳,這使它們成為土壤碳的潛在貢獻(xiàn)者。然而,自然條件下微塑料降解可能需要幾十到幾千年的時(shí)間[57],且微塑料的衍生碳不具有與土壤有機(jī)碳相同的生態(tài)功能。因此,一些研究人員建議將這部分碳排除在土壤碳儲(chǔ)量之外[58]。雖然傳統(tǒng)微塑料很難降解,但是微塑料仍然可以通過(guò)太陽(yáng)輻射和微生物定殖等驅(qū)動(dòng)因素使微塑料中的可溶性有機(jī)碳浸出到環(huán)境中[59]。并且微塑料的存在還會(huì)通過(guò)改變土壤理化性質(zhì)和微生物特性來(lái)促進(jìn)土壤可溶性有機(jī)碳的水解轉(zhuǎn)化[60]。例如,Liu 等[61]發(fā)現(xiàn),當(dāng)土壤中聚丙烯質(zhì)量分?jǐn)?shù)在28% 時(shí),熒光素雙乙酸水解酶和酚氧化酶的活性升高,促進(jìn)土壤有機(jī)質(zhì)的水解,土壤中可溶性有機(jī)碳的含量提高35%。陸生植物的作用也是土壤碳循環(huán)中重要的一環(huán)。陸生植物光合作用將CO2固定后,再通過(guò)根沉積和凋落物的分解將固定的碳分配到土壤中。而微塑料的存在會(huì)導(dǎo)致植物光合作用和生長(zhǎng)性能的變化[11],從而影響到植物-土壤-大氣系統(tǒng)的碳循環(huán)。例如,Colzi 等[62]將葫蘆暴露在微塑料中,發(fā)現(xiàn)葫蘆的地上部與地下部生物量、葉面積、葉綠素含量和光合效率都有不同程度的下降。同時(shí),微塑料的存在還會(huì)通過(guò)調(diào)節(jié)土壤微生物群落結(jié)構(gòu)和活性來(lái)影響植物殘留物的分解[63]。微生物作為土壤生態(tài)系統(tǒng)中碳循環(huán)的主要驅(qū)動(dòng)力,塑料際微生物群落組成受微塑料性質(zhì)的影響,與土壤微生物群落組成產(chǎn)生顯著差異。一些細(xì)菌門(mén)類(lèi),如變形菌門(mén)、擬桿菌門(mén)和放線菌門(mén),在土壤有機(jī)質(zhì)的降解中起著至關(guān)重要的作用。土壤微生物與微塑料相互作用的差異是微塑料對(duì)土壤碳循環(huán)影響差異的主要原因。
關(guān)于土壤塑料際對(duì)碳循環(huán)的影響,有研究給出了一些假設(shè)來(lái)解釋?zhuān)?4]?!拔⑸锎煺邸奔僬f(shuō)認(rèn)為,微塑料的存在增加了土壤碳的分子多樣性,而碳化合物的分子多樣性可以增加土壤有機(jī)碳的持久性[65],因此微塑料的存在會(huì)使微生物更難處理有機(jī)碳。而“正負(fù)啟動(dòng)假說(shuō)”認(rèn)為,如果添加基質(zhì)有利于現(xiàn)有土壤有機(jī)碳的礦化,則可能存在正啟動(dòng)。啟動(dòng)是一種描述碳基質(zhì)的添加如何影響原生土壤有機(jī)碳礦化的機(jī)制。例如,有研究發(fā)現(xiàn),定殖在聚羥基丁酸戊酸共聚酯上的微生物群落可以很容易地將聚羥基丁酸戊酸共聚酯作為有效的碳源,從而提高微生物特定的生長(zhǎng)速度,增加土壤塑料際中的微生物生物量[66];相反,則可能存在負(fù)啟動(dòng)。例如,在添加易礦化碳的情況下,可能會(huì)使土壤中的微塑料被微生物優(yōu)先代謝掉[67]??偟膩?lái)說(shuō),微塑料會(huì)從多個(gè)方面對(duì)土壤碳循環(huán)造成影響。然而,目前土壤塑料際對(duì)土壤碳的影響機(jī)制研究較少且沒(méi)有統(tǒng)一的研究結(jié)果,未來(lái)還需要更多的研究探索。
3.3 塑料際多種污染物的富集與生態(tài)風(fēng)險(xiǎn)
微塑料在氫鍵、靜電相互作用和范德華力等作用下,具有很強(qiáng)的吸附和富集環(huán)境有害污染物,如重金屬和有機(jī)污染物的能力[68]。在塑料際形成過(guò)程中,有機(jī)和無(wú)機(jī)懸浮液的黏附使得重金屬更容易集聚在微塑料上[69]。塑料際引起的微塑料老化會(huì)改變微塑料的物理化學(xué)性質(zhì),從而為重金屬提供更多的吸附位點(diǎn)[70]。微塑料與重金屬之間的相互作用還會(huì)改變土壤食物鏈中重金屬的生物有效性[71],導(dǎo)致重金屬的生物積累和毒性。微塑料和重金屬會(huì)對(duì)土壤生物產(chǎn)生拮抗或協(xié)同作用[72]。拮抗作用是指微塑料會(huì)降低重金屬暴露在環(huán)境介質(zhì)中的濃度,從而降低其環(huán)境毒性。相反,協(xié)同作用會(huì)使土壤生態(tài)系統(tǒng)更容易受到微塑料與重金屬?gòu)?fù)合污染的影響,復(fù)合污染物的環(huán)境毒性可能比單一污染物的環(huán)境毒性更大。例如,Huang 等[73]采用Meta 分析微塑料與重金屬鎘的復(fù)合污染時(shí)發(fā)現(xiàn),微塑料使鎘在植物地上部和地下部的積累量分別提高了14.6% 和13.5%,并且微塑料誘導(dǎo)土壤有效鎘濃度顯著升高(9.75%)。微塑料與鎘的復(fù)合污染對(duì)植物生長(zhǎng)具有協(xié)同作用。這些協(xié)同作用機(jī)制包括對(duì)植物光合作用的抑制和氧化損傷的加重。微塑料作為土壤中重金屬的載體,提高了重金屬的生物利用率,使重金屬容易被生物吸收并轉(zhuǎn)移到食物網(wǎng)中。在獨(dú)特的生物體中,重金屬很容易被解吸,對(duì)人體健康構(gòu)成威脅[74]。
與重金屬類(lèi)似,微塑料可以成為土壤中許多有機(jī)污染物的載體。微塑料可將污染物引入食物鏈,并通過(guò)生物攝食和捕食在食物網(wǎng)中流動(dòng),導(dǎo)致污染物在生物體內(nèi)的生物積累和生物放大。微塑料對(duì)有機(jī)污染物具有特殊的親和力,其吸附機(jī)制,如氫鍵、疏水相互作用和π-π 相互作用,可能是由微塑料的特性和結(jié)構(gòu)決定的[70]。迄今為止,已經(jīng)有多種機(jī)污染物被微塑料吸附的報(bào)道,包括多環(huán)芳烴[75] 、多氯聯(lián)苯[76]、有機(jī)氯農(nóng)藥和抗生素[77]。近年來(lái),塑料際對(duì)有機(jī)污染物的吸附和代謝引起了科學(xué)界的廣泛關(guān)注??偟膩?lái)說(shuō),塑料際對(duì)它們的綜合影響機(jī)制可能有以下幾點(diǎn):(1)影響土壤中污染物的吸附;(2)影響重金屬的形態(tài)和生物利用度;(3)干擾有機(jī)污染物的降解;(4)與污染物的共暴露改變了它們的生物積累和毒性。
土壤塑料際被認(rèn)為是致病菌和抗生素抗性基因(antibiotic resistance genes,ARGs)的儲(chǔ)存庫(kù),加速了全球抗生素耐藥性的傳播。ARGs 是天然存在的編碼抗生素抗性功能的基因片段。塑料污染通過(guò)提供數(shù)萬(wàn)億個(gè)人工微棲息地來(lái)改變真菌的生態(tài)位,病原體可能在這些微棲息地(塑料際)積聚、繁殖和進(jìn)化[78]。微塑料可以選擇性地富集ARGs,甚至可以富集到高出周?chē)h(huán)境5 000 倍的ARGs[79]。在各種環(huán)境介質(zhì)中,微塑料表面檢測(cè)到大量的ARGs。例如,聚乙烯可以顯著富集sul1、sulA/folP-01、tetA、tetC、tetX 和ermE 等ARGs[80]。微塑料與ARGs 之間的相互作用使得微塑料為ARGs 提供載體并形成塑料際[81],促進(jìn)ARGs 的積累[82]與基因交換,增強(qiáng)其在環(huán)境中的遷移[83]。越來(lái)越多的研究表明,微塑料可以作為致病菌和ARGs 的載體,影響土壤生態(tài)系統(tǒng)健康[84],加速疾病傳播并對(duì)全球人類(lèi)健康構(gòu)成潛在威脅[85]。有研究表明,塑料際對(duì)致病菌群落的聚集過(guò)程有促進(jìn)作用,并通過(guò)分析發(fā)現(xiàn),ARGs、毒性因子基因與塑料際細(xì)菌之間存在顯著相關(guān)性[86]。Li等[87]采用宏基因組分析方法研究了聚乙烯、聚己二酸/對(duì)苯二甲酸丁二酯和聚乳酸微塑料的ARGs 和毒性因子,結(jié)果發(fā)現(xiàn),與土壤和聚乙烯相比,聚己二酸/對(duì)苯二甲酸丁二酯和聚乳酸的塑料際中能檢出更多ARGs 和毒性因子,其多樣性和豐度值也顯著高于土壤和聚乙烯塑料際。其中,放線菌門(mén)是土壤和聚乙烯塑料際中四環(huán)素和糖肽類(lèi)抗性基因的主要宿主,而聚己二酸/對(duì)苯二甲酸丁二酯和聚乳酸塑料際中多藥抗性基因的主要宿主變?yōu)樽冃尉T(mén)。此外,還鑒定出3 種人類(lèi)致病菌,分別為少動(dòng)鞘脂單胞菌(Sphingomonas paucimobilis)、植物乳桿菌(Lactoba?cillus plantarum)和銅綠假單胞菌 (Pseudomonas ae?ruginosa)。土壤塑料際會(huì)攜帶致病菌,如副溶血性弧菌(Vibrio parahaemolyticus)和埃希氏志賀氏菌[18](Escherichia-Shigella),并富集ARGs[88]。耕地土壤生態(tài)系統(tǒng)中聚乙烯的增加會(huì)導(dǎo)致動(dòng)物寄生蟲(chóng)、人類(lèi)致病菌和植物致病菌的豐度增加[18]。土壤塑料際微生物可能是土壤生態(tài)系統(tǒng)中真菌致病菌的持續(xù)宿主,對(duì)世界范圍內(nèi)真菌感染的流行病學(xué)產(chǎn)生嚴(yán)重后果[89]。
4 展望
近年來(lái),微塑料對(duì)土壤微生物及周?chē)h(huán)境產(chǎn)生了不可忽視的影響,隨著水生塑料際概念的提出,研究人員對(duì)土壤生態(tài)系統(tǒng)塑料際的關(guān)注日益增加。本文主要闡述了微塑料與土壤微生物之間的相互作用,微塑料的存在影響了土壤微生物生存環(huán)境的變化,微生物選擇性地附著在微塑料表面,增強(qiáng)了微塑料與土壤生態(tài)系統(tǒng)中其他污染物的聯(lián)合效應(yīng),也加劇了微塑料在土壤生態(tài)系統(tǒng)中的生態(tài)風(fēng)險(xiǎn)。同時(shí),土壤微生物在微塑料的降解過(guò)程中發(fā)揮著至關(guān)重要的作用。降解后的亞微米級(jí)塑料和納米級(jí)塑料可能攜帶者其他污染物及致病菌進(jìn)入土壤生物體內(nèi),甚至危害人體健康。但是現(xiàn)有的研究并不能全面揭示塑料污染形成塑料際帶來(lái)的生態(tài)影響,還需要對(duì)塑料際微塑料污染和土壤微生物進(jìn)行更詳細(xì)和可靠的研究,了解它們對(duì)土壤環(huán)境乃至全球變化的影響。未來(lái)的研究應(yīng)更注重以下方面:
1)土壤塑料際生態(tài)功能及其與其他生態(tài)系統(tǒng)的關(guān)聯(lián)性。除了對(duì)塑料際細(xì)菌群落的研究,真菌和微型真核生物群落在土壤生態(tài)系統(tǒng)中的作用與功能同樣不可忽視。同時(shí),塑料際微生物與周?chē)寥牢⑸锏姆N類(lèi)、結(jié)構(gòu)與功能差異也值得更深入的研究。為了更加深入地了解土壤塑料際在生物地球化學(xué)過(guò)程中的影響,應(yīng)對(duì)其生態(tài)功能以及與其他生態(tài)系統(tǒng)的關(guān)系進(jìn)行更加系統(tǒng)性的研究。
2)微塑料的遷移機(jī)制。塑料際微生物群落可能會(huì)隨著微塑料或更小尺寸的納米塑料遷移到其他生態(tài)系統(tǒng)中去。土壤微生物與微塑料的結(jié)合,會(huì)增強(qiáng)微生物在生態(tài)系統(tǒng)中的流動(dòng)性,微生物可能會(huì)以微生物群落的方式,隨著風(fēng)力或地下徑流的作用跟隨微塑料遷移到更多生態(tài)系統(tǒng)中去。這種遷移方式是否會(huì)對(duì)其他生態(tài)系統(tǒng)造成影響,更小尺寸的納米塑料是否有其他可能的遷移機(jī)制,需要更加深入的研究。
3)塑料際對(duì)土壤碳循環(huán)的影響機(jī)制。微塑料作為土壤的人工碳輸入,會(huì)對(duì)土壤碳儲(chǔ)存或損失的相關(guān)過(guò)程造成影響。然而,關(guān)于土壤塑料際對(duì)碳循環(huán)的影響,如土壤有機(jī)碳的利用、根系沉積、溫室氣體排放、凋落物分解等,目前還存在很大的研究空白值得進(jìn)一步探究。
參考文獻(xiàn) References
[1] RILLIG M C,KIM S W,ZHU Y G.The soil plastisphere[J].
Nature reviews microbiology,2024,22(2):64-74.
[2] LIU K,WU T N,WANG X H,et al.Consistent transport of
terrestrial microplastics to the ocean through atmosphere[J].
Environmental science amp; technology,2019,53(18):10612-
10619.
[3] VAN SEBILLE E,WILCOX C,LEBRETON L,et al. A
global inventory of small floating plastic debris[J/OL]. Environmental
research letters,2015,10(12):124006[2024-06-
02].https://doi.org/10.1088/1748-9326/10/12/124006 .
[4] WEN X F,DU C Y,XU P,et al.Microplastic pollution in surface
sediments of urban water areas in Changsha,China:abundance,
composition,surface textures[J].Marine pollution bulletin,
2018,136:414-423.
[5] LAW K L,THOMPSON R C. Oceans. microplastics in the
seas[J].Science,2014,345(6193):144-145.
[6] GALLOWAY T S,LEWIS C N. Marine microplastics spell
big problems for future generations[J].PNAS,2016,113(9):
2331-2333.
[7] GEYER R,JAMBECK J R,LAW K L.Production,use,and
fate of all plastics ever made[J/OL].Science advances,2017,3
(7):e1700782[2024-06-02]. https://www. science. org/doi/
10.1126/sciadv.1700782 .
[8] HORTON A A,WALTON A,SPURGEON D J,et al.Microplastics
in freshwater and terrestrial environments:evaluating
the current understanding to identify the knowledge gaps
and future research priorities[J]. Science of the total environment,
2017,586:127-141.
[9] DE SOUZA MACHADO A A,KLOAS W,ZARFL C,et al.
Microplastics as an emerging threat to terrestrial ecosystems
[J].Global change biology,2018,24(4):1405-1416.
[10] DE SOUZA MACHADO A A,LAU C W,TILL J,et al.Impacts
of microplastics on the soil biophysical environment[J].
Environmental science amp; technology,2018,52(17):9656-
9665.
[11] DE SOUZA MACHADO A A,LAU C W,KLOAS W,et al.
Microplastics can change soil properties and affect plant performance
[J]. Environmental science amp; technology,2019,53
(10):6044-6052.
[12] ZETTLER E R,MINCER T J,AMARAL-ZETTLER L A.
Life in the “plastisphere” :microbial communities on plastic
marine debris[J].Environmental science amp; technology,2013,
47(13):7137-7146.
[13] SUN Y Z,SHI J,WANG X,et al. Deciphering the mecha‐
nisms shaping the plastisphere microbiota in soil[J/OL].mSystems,
2022,7(4):e0035222[2024-06-02]. https://doi. org/
10.1128/msystems.00352-22.
[14] STABNIKOVA O,STABNIKOV V,MARININ A,et al.
Microbial life on the surface of microplastics in natural waters
[J/OL].Applied sciences,2021,11(24):11692[2024-06-02].
https://doi.org/10.3390/app112411692.
[15] LI H Q,SHEN Y J,WANG W L,et al.Soil pH has a stronger
effect than arsenic content on shaping plastisphere bacterial
communities in soil[J/OL]. Environmental pollution,2021,
287: 117339 [2024-06-02]. https://doi. org/10.1016/j.
envpol.2021.117339.
[16] BASILI M,QUERO G M,GIOVANNELLI D,et al. Major
role of surrounding environment in shaping biofilm community
composition on marine plastic debris[J/OL].Frontiers in marine
science,2020,7:262[2024-06-02]. https://doi. org/
10.3389/fmars.2020.00262 .
[17] ZHU D,MA J,LI G,et al.Soil plastispheres as hotpots of antibiotic
resistance genes and potential pathogens[J].The ISME
journal,2022,16(2):521-532.
[18] LI H Z,ZHU D,LINDHARDT J H,et al.Long-term fertilization
history alters effects of microplastics on soil properties,microbial
communities,and functions in diverse farmland ecosystem
[J]. Environmental science amp; technology,2021,55(8):
4658-4668.
[19] LI Z L,F(xiàn)ENG C H,LEI J M,et al.Farmland microhabitat mediated
by a residual microplastic film:microbial communities
and function[J].Environmental science amp; technology,2024,58
(8):3654-3664.
[20] TANG K H D.Terrestrial and aquatic plastisphere:formation,
characteristics,and influencing factors[J/OL]. Sustainability,
2024,16(5):2163[2024-06-02]. https://doi. org/10.3390/
su16052163 .
[21] JIAO Y Y,ZHANG G Y,AI X Y,et al.Comparison of the effects
of LDPE and PBAT film residues on soil microbial ecology
[J/OL].Current microbiology,2024,81(7):185[2024-06-
02].https://doi.org/10.1007/s00284-024-03722-9.
[22] RüTHI J,B?LSTERLI D,PARDI-COMENSOLI L,et al.
The “plastisphere” of biodegradable plastics is characterized
by specific microbial taxa of alpine and Arctic soils[J/OL].
Frontiers in environmental science,2020,8:562263[2024-06-
02].https://doi.org/10.3389/fenvs.2020.562263.
[23] WEN B,LIU J H,ZHANG Y,et al.Community structure and
functional diversity of the plastisphere in aquaculture waters:
does plastic color matter?[J/OL].Science of the total environment,
2020,740:140082[2024-06-02]. https://doi. org/
10.1016/j.scitotenv.2020.140082.
[24] PARRISH K,F(xiàn)AHRENFELD N L. Microplastic biofilm in
fresh- and wastewater as a function of microparticle type and
size class[J].Environmental science:water research amp; technology,
2019,5(3):495-505.
[25] ZHANG W H,LIANG S X,GROSSART H P,et al.Convergence
effect during spatiotemporal succession of lacustrine
plastisphere:loss of priority effects and turnover of microbial
species[J/OL]. ISME communications,2024,4(1):ycae056
[2024-06-02].https://doi.org/10.1093/ismeco/ycae056 .
[26] MIAO L Z,WANG C Q,ADYEL T M,et al.Microbial carbon
metabolic functions of biofilms on plastic debris influenced
by the substrate types and environmental factors[J/OL].Environment
international,2020,143:106007 [2024-06-02].
https://doi.org/10.1016/j.envint.2020.106007.
[27] PINTO M,LANGER T M,HüFFER T,et al.The composition
of bacterial communities associated with plastic biofilms
differs between different polymers and stages of biofilm succession
[J/OL].PLoS One,2019,14(6):e0217165[2024-06-02].
https://doi.org/10.1371/journal.pone.0217165.
[28] AMMAR Y,SWAILES D,BRIDGENS B,et al.Influence of
surface roughness on the initial formation of biofilm[J]. Surface
and coatings technology,2015,284:410-416.
[29] DEY S,ROUT A K,BEHERA B K,et al.Plastisphere community
assemblage of aquatic environment:plastic-microbe interaction,
role in degradation and characterization technologies
[J/OL]. Environmental microbiome,2022,17(1):32[2024-
06-02].https://doi.org/10.1186/s40793-022-00430-4.
[30] TANG K H D. Microplastics in agricultural soils in China:
sources,impacts and solutions[J/OL]. Environmental pollution,
2023,322:121235 [2024-06-02]. https://doi. org/
10.1016/j.envpol.2023.121235.
[31] DENG W B,WANG Y J,WANG Z H,et al.Effects of photoaging
on structure and characteristics of biofilms on microplastic
in soil:biomass and microbial community[J/OL]. Journal
of hazardous materials,2024,467:133726[2024-06-02].
https://doi.org/10.1016/j.jhazmat.2024.1337 .
[32] REN X W,TANG J C,LIU X M,et al.Effects of microplastics
on greenhouse gas emissions and the microbial community in fertilized
soil[J/OL]. Environmental pollution,2020,256:113347
[2024-06-02]. https://doi.org/10.1016/j.envpol.2019.113347.
[33] ZHU B K,F(xiàn)ANG Y M,ZHU D,et al.Exposure to nanoplastics
disturbs the gut microbiome in the soil oligochaete Enchy?
traeus crypticus [J]. Environmental pollution,2018,239:
408-415.
[34] MU?OZ K,SCHMIDT-HEYDT M,STOLL D,et al.Effect
of plastic mulching on mycotoxin occurrence and mycobiome
abundance in soil samples from asparagus crops[J].Mycotoxin
research,2015,31(4):191-201.
[35] NG E L,HUERTA LWANGA E,ELDRIDGE S M,et al.
An overview of microplastic and nanoplastic pollution in agroecosystems
[J]. Science of the total environment,2018,627:
1377-1388.
[36] SáNCHEZ C. Fungal potential for the degradation of petroleum-
based polymers:an overview of macro- and microplastics
biodegradation[J/OL].Biotechnology advances,2020,40:
107501 [2024-06-02]. https://doi. org/10.1016/j. biotechadv.
2019.107501.
[37] MACLEOD M,ARP H P H,TEKMAN M B,et al.The global
threat from plastic pollution[J].Science,2021,373(6550):
61-65.
[38] GU J D.Microbiological deterioration and degradation of synthetic
polymeric materials:recent research advances[J].International
biodeterioration amp; biodegradation,2003,52(2):
69-91.
[39] DUAN J J,BOLAN N,LI Y,et al.Weathering of microplastics
and interaction with other coexisting constituents in terrestrial
and aquatic environments[J/OL].Water research,2021,
196:117011[2024-06-02]. https://doi. org/10.1016/j. watres.
2021.11701.
[40] ZHANG K,HAMIDIAN A H,TUBI? A,et al. Understanding
plastic degradation and microplastic formation in the environment:
a review[J/OL].Environmental pollution,2021,274:116554
[2024-06-02].https://doi.org/10.1016/j.envpol.2021.116554 .
[41] TEUTEN E L,SAQUING J M,KNAPPE D R U,et al.
Transport and release of chemicals from plastics to the environment
and to wildlife[J].Philosophical transactions of the Royal
Society of London. Series B,Biological sciences,2009,364
(1526):2027-2045.
[42] URBANEK A K,MIRO?CZUK A M,GARCíA-MARTíN
A,et al. Biochemical properties and biotechnological applications
of microbial enzymes involved in the degradation of polyester-
type plastics[J/OL]. Biochimica et biophysica acta,
2020,1868(2) :140315[2024-06-02]. https://doi. org/
10.1016/j.bbapap.2019.140315 .
[43] LUCAS N,BIENAIME C,BELLOY C,et al. Polymer biodegradation:
mechanisms and estimation techniques:a review
[J].Chemosphere,2008,73(4):429-442.
[44] LI L Z,LUO Y M,LI R J,et al. Effective uptake of submicrometre
plastics by crop plants via a crack-entry mode[J].Nature
sustainability,2020,3:929-937.
[45] YUAN J H,MA J,SUN Y R,et al.Microbial degradation and
other environmental aspects of microplastics/plastics[J/OL].
The science of the total environment,2020,715:136968[2024-
06-02].https://doi.org/10.1016/j.scitotenv.2020.136968.
[46] GAO J,PAN S Z,LI P F,et al.Vertical migration of microplastics
in porous media:multiple controlling factors under
wet-dry cycling[J/OL].Journal of hazardous materials,2021,
419: 126413 [2024-06-02]. https://doi. org/10.1016/j.
jhazmat.2021.126413.
[47] YU Y X,F(xiàn)LURY M. Current understanding of subsurface
transport of micro- and nanoplastics in soil[J/OL]. Vadose
zone journal,2021,20(2):e20108[2024-06-02].https://doi.
org/10.1002/vzj2.20108.
[48] MINTENIG S M,L?DER M G J,PRIMPKE S,et al.Low
numbers of microplastics detected in drinking water from
ground water sources[J].The science of the total environment,
2019,648:631-635.
[49] ZHAO S L,ZHANG Z Q,CHEN L,et al.Review on migration,
transformation and ecological impacts of microplastics in
soi[l J/OL].Applied soil ecology,2022,176:104486[2024-06-
02].https://doi.org/10.1016/j.apsoil.2022.104486 .
[50] GHOLAMI H,MOHAMMADIFAR A,BUI D T,et al.Mapping
wind erosion hazard with regression-based machine learning
algorithms[J/OL]. Scientific reports,2020,10(1):20494
[2024-06-02].https://doi.org/10.1038/s41598-020-77567-0.
[51] KIM S W,AN Y J.Soil microplastics inhibit the movement of
springtail species[J]. Environment international,2019,126:
699-706.
[52] WAN Y,WU C X,XUE Q,et al.Effects of plastic contamination
on water evaporation and desiccation cracking in soil[J].
Science of the total environment,2019,654:576-582.
[53] RUBOL S,MANZONI S,BELLIN A,et al. Modeling soil
moisture and oxygen effects on soil biogeochemical cycles including
dissimilatory nitrate reduction to ammonium (DNRA)
[J].Advances in water resources,2013,62:106-124.
[54] YU Y X,BATTU A K,VARGA T,et al.Minimal impacts of
microplastics on soil physical properties under environmentally
relevant concentrations[J].Environmental science amp; technology,
2023,57(13):5296-5304.
[55] SUN Y Z,WU M C,XIE S Y,et al.Homogenization of bacterial
plastisphere community in soil:a continental-scale microcosm
study[J/OL]. ISME communications,2024,4(1):
ycad012 [2024-06-02]. https://doi. org/10.1093/ismeco/
ycad012.
[56] WANG W F,ZHANG Z Y,GAO J,et al.The impacts of microplastics
on the cycling of carbon and nitrogen in terrestrial
soil ecosystems:progress and prospects[J/OL].Science of the
total environment,2024,915:169977[2024-06-02]. https://
doi.org/10.1016/j.scitotenv.2024.169977.
[57] CHAMAS A,MOON H,ZHENG J J,et al.Degradation rates
of plastics in the environment[J]. ACS sustainable chemistry
amp; engineering,2020,8(9):3494-3511.
[58] RILLIG M C. Microplastic disguising as soil carbon storage
[J].Environmental science amp; technology,2018,52(11):6079-
6080.
[59] ROMERA-CASTILLO C,PINTO M,LANGER T M,et al.
Dissolved organic carbon leaching from plastics stimulates microbial
activity in the ocean[J/OL]. Nature communications,
2018,9(1):1430[2024-06-02]. https://doi. org/10.1038/
s41467-018-03798-5.
[60] ZHANG Y X,LI X,XIAO M,et al. Effects of microplastics
on soil carbon dioxide emissions and the microbial functional
genes involved in organic carbon decomposition in agricultural
soil[J/OL]. Science of the total environment,2022,806(Pt
3):150714[2024-06-02]. https://doi. org/10.1016/j. scitotenv.
2021.150714.
[61] LIU H F,YANG X M,LIU G B,et al.Response of soil dis‐
solved organic matter to microplastic addition in Chinese loess
soi[l J].Chemosphere,2017,185:907-917.
[62] COLZI I,RENNA L,BIANCHI E,et al.Impact of microplastics
on growth,photosynthesis and essential elements in Cucur?
bita pepo L.[J/OL]. Journal of hazardous materials,2022,
423: 127238 [2024-06-02]. https://doi. org/10.1016/j.
jhazmat.2021.127238.
[63] DU J J,QV W,NIU Y L,et al.Nanoplastic pollution inhibits
stream leaf decomposition through modulating microbial metabolic
activity and fungal community structure[J/OL]. Journal
of hazardous materials,2022,424:127392[2024-06-02].
https://doi.org/10.1016/j.jhazmat.2021.127392 .
[64] RILLIG M C,LEIFHEIT E,LEHMANN J.Microplastic effects
on carbon cycling processes in soils[J/OL].PLoS biology,
2021,19(3):e3001130[2024-06-02]. https://doi. org/
10.1371/journal.pbio.3001130 .
[65] LEHMANN J,HANSEL C M,KAISER C,et al.Persistence
of soil organic carbon caused by functional complexity[J].Nature
geoscience,2020,13:529-534.
[66] ZHOU J,GUI H,BANFIELD C C,et al. The microplastisphere:
biodegradable microplastics addition alters soil microbial
community structure and function[J/OL]. Soil biology and
biochemistry,2021,156:108211[2024-06-02]. https://doi.
org/10.1016/j.soilbio.2021.108211.
[67] DECIUCIES S,WHITMAN T,WOOLF D,et al. Priming
mechanisms with additions of pyrogenic organic matter to soil
[J].Geochimica et cosmochimica acta,2018,238:329-342.
[68] CAO Y X,ZHAO M J,MA X Y,et al.A critical review on the
interactions of microplastics with heavy metals:mechanism and
their combined effect on organisms and humans[J/OL]. Science
of the total environment,2021,788:147620[2024-06-02].
https://doi.org/10.1016/j.scitotenv.2021.147620 .
[69] JOHANSEN M P,CRESSWELL T,DAVIS J,et al.Biofilmenhanced
adsorption of strong and weak cations onto different
microplastic sample types:use of spectroscopy,microscopy
and radiotracer methods[J]. Water research,2019,158:
392-400.
[70] REN Z F,GUI X Y,XU X Y,et al.Microplastics in the soilgroundwater
environment:aging,migration,and co-transport
of contaminants:a critical review[J/OL].Journal of hazardous
materials,2021,419:126455[2024-06-02]. https://doi. org/
10.1016/j.jhazmat.2021.126455 .
[71] DISSANAYAKE P D,KIM S,SARKAR B,et al.Effects of
microplastics on the terrestrial environment:a critical review
[J/OL].Environmental research,2022,209:112734[2024-06-
02].https://doi.org/10.1016/j.envres.2022.112734.
[72] BHAGAT J,NISHIMURA N,SHIMADA Y. Toxicological
interactions of microplastics/nanoplastics and environmental
contaminants:current knowledge and future perspectives[J/
OL].Journal of hazardous materials,2021,405:123913[2024-
06-02].https://doi.org/10.1016/j.jhazmat.2020.123913 .
[73] HUANG F Y,HU J Z,CHEN L,et al.Microplastics may increase
the environmental risks of Cd via promoting Cd uptake
by plants:a Meta-analysis[J/OL].Journal of hazardous materials,
2023,448:130887 [2024-06-02]. https://doi. org/
10.1016/j.jhazmat.2023.130887.
[74] LIU B Y,ZHAO S L,QIU T Y,et al.Interaction of microplastics
with heavy metals in soil:mechanisms,influencing factors
and biological effects[J/OL].Science of the total environment,
2024,918:170281[2024-06-02]. https://doi. org/10.1016/j.
scitotenv.2024.170281.
[75] LIU Y,SHAO H,LIU J N,et al.Transport and transformation
of microplastics and nanoplastics in the soil environment:a
critical review[J]. Soil use and management,2021,37(2):
224-242.
[76] WANG J,LIU X H,LI Y,et al.Microplastics as contaminants
in the soil environment:a mini-review[J].Science of the total
environment,2019,691:848-857.
[77] VERLA A W,ENYOH C E,VERLA E N,et al.Microplastic–
toxic chemical interaction:a review study on quantified levels,
mechanism and implication[J/OL].SN applied sciences,2019,
1(11):1400[2024-06-02]. https://doi.org/10.1007/s42452-
019-1352-0.
[78] GKOUTSELIS G,ROHRBACH S,HARJES J,et al. Plastiphily
is linked to generic virulence traits of important human
pathogenic fungi[J/OL]. Communications earth amp; environment,
2024,5:51[2024-06-02]. https://doi. org/10.1038/
s43247-023-01127-3.
[79] WANG S S,XUE N N,LI W F,et al.Selectively enrichment
of antibiotics and ARGs by microplastics in river,estuary and
marine waters[J/OL].Science of the total environment,2020,
708:134594[2024-06-02]. https://doi. org/10.1016/j. scitotenv.
2019.134594.
[80] WANG J,QIN X,GUO J B,et al. Evidence of selective enrichment
of bacterial assemblages and antibiotic resistant genes
by microplastics in urban rivers[J/OL].Water research,2020,
183:116113[2024-06-02]. https://doi. org/10.1016/j. watres.
2020.116113 .
[81] DONG H,CHEN Y L,WANG J,et al.Interactions of microplastics
and antibiotic resistance genes and their effects on the
aquaculture environments[J/OL].Journal of hazardous materials,
2021,403:123961 [2024-06-02]. https://doi. org/
10.1016/j.jhazmat.2020.123961.
[82] STENGER K S,WIKMARK O G,BEZUIDENHOUT C C,
et al.Microplastics pollution in the ocean:potential carrier of resistant
bacteria and resistance genes[J/OL]. Environmental
pollution,2021,291:118130[2024-06-02]. https://doi. org/
10.1016/j.envpol.2021.118130.
[83] RUMMEL C D,LECHTENFELD O J,KALLIES R,et al.
Conditioning film and early biofilm succession on plastic surfaces
[J].Environmental science amp; technology,2021,55(16):
11006-11018.
[84] 朱永官,朱冬,許通,等.(微)塑料污染對(duì)土壤生態(tài)系統(tǒng)的影
響:進(jìn)展與思考[J]. 農(nóng)業(yè)環(huán)境科學(xué)學(xué)報(bào),2019,38(1):1-6.
ZHU Y G,ZHU D,XU T,et al.Impacts of(micro)plastics on
soil ecosystem:progress and perspective[J]. Journal of agroenvironment
science,2019,38(1):1-6 (in Chinese with English
abstract)..
[85] MA J,ZHAO J H,ZHU Z L,et al.Effect of microplastic size on
the adsorption behavior and mechanism of triclosan on polyvinyl
chloride[J/OL]. Environmental pollution,2019,254:113104
[2024-06-02]. https://doi.org/10.1016/j.envpol.2019.113104.
[86] LIN D,XU J Y,WANG L,et al.Long-term application of organic
fertilizer prompting the dispersal of antibiotic resistance
genes and their health risks in the soil plastisphere[J/OL].Environment
international,2024,183:108431[2024-06-02].
https://doi.org/10.1016/j.envint.2024.108431.
[87] LI K,XU L B,BAI X Y,et al.Potential environmental risks of
field bio/non-degradable microplastic from mulching residues in
farmland:evidence from metagenomic analysis of plastisphere[J/
OL]. Journal of hazardous materials,2024,465:133428[2024-
06-02]. https://doi.org/10.1016/j.jhazmat.2024.133428.
[88] XIE H F,CHEN J J,F(xiàn)ENG L M,et al.Chemotaxis-selective
colonization of mangrove rhizosphere microbes on nine different
microplastics[J/OL]. Science of the total environment,
2021,752:142223[2024-06-02]. https://doi. org/10.1016/j.
scitotenv.2020.142223.
[89] GKOUTSELIS G,ROHRBACH S,HARJES J,et al.Microplastics
accumulate fungal pathogens in terrestrial ecosystems
[J/OL].Scientific reports,2021,11(1):13214[2024-06-02].
https://doi.org/10.1038/s41598-021-92405-7.
(責(zé)任編輯:張志鈺)