太湖胥口灣表層水和沉積物中多環(huán)芳烴的濃度水平及生態(tài)風(fēng)險

李曉靜，于玉玲，馬莉，曾祥英，余應(yīng)新，張曉嵐,*

1. 上海大學(xué) 環(huán)境與化學(xué)工程學(xué)院 環(huán)境污染與健康研究所，上海 200444 2. 中國科學(xué)院廣州地球化學(xué)研究所 有機地球化學(xué)國家重點實驗室，廣州 510000

?

太湖胥口灣表層水和沉積物中多環(huán)芳烴的濃度水平及生態(tài)風(fēng)險

李曉靜1，于玉玲1，馬莉1，曾祥英2，余應(yīng)新1，張曉嵐1,*

1. 上海大學(xué) 環(huán)境與化學(xué)工程學(xué)院 環(huán)境污染與健康研究所，上海 200444 2. 中國科學(xué)院廣州地球化學(xué)研究所 有機地球化學(xué)國家重點實驗室，廣州 510000

多環(huán)芳烴；表層水；沉積物；生態(tài)風(fēng)險；時空變化；太湖

多環(huán)芳烴(polycyclic aromatic hydrocarbons，PAHs)是一類由2個及2個以上苯環(huán)組成的有機污染物，原型及其衍生物達400多種[1]。具有致癌性的多環(huán)芳烴主要集中在4環(huán)及以上，其中苯并[a]芘(BaP)被確定為強致癌物質(zhì)，苯并(a)蒽(BaA)、苯并(b)熒蒽(BbF)、苯并(k)熒蒽(BkF)、二苯并(a,h)蒽(DahA)和茚并(123-cd)芘(IcdP)為極可能的致癌物，它們均具有很強的生態(tài)與健康毒性。美國環(huán)保局(USEPA)將16種對人體健康危害較大的PAHs列入了優(yōu)先控制污染物名單[2]。

多環(huán)芳烴廣泛分布在大氣、表層水、土壤和食品等環(huán)境介質(zhì)中。由于具有疏水性和親脂性，PAHs在水中的溶解性較差，主要被懸浮顆粒物吸附，并可隨懸浮顆粒物沉降至沉積物，沉積物中的PAHs經(jīng)過擾動作用等也能夠重新釋放進入表層水，成為新的污染源[3]。隨著研究工作的廣泛開展，不同水環(huán)境中PAHs研究也取得巨大進展，積累了大量數(shù)據(jù)。國內(nèi)不少地區(qū)存在較為嚴重的PAHs污染[4-7]?？傮w來說，我國水域環(huán)境中PAHs污染分布具有以下特點，港口和河口地區(qū)的污染水平較高，而內(nèi)陸湖泊、河流則呈現(xiàn)相對比較輕的污染狀態(tài)[8]，水文、氣候和地區(qū)經(jīng)濟等多種因素均可影響PAHs的污染水平。

太湖是我國五大淡水湖之一，它位于華東地區(qū)，瀕臨蘇州和無錫，在長江三角洲流域中占有重要的地位，是無錫等地的飲用水源地[9]。隨著經(jīng)濟的快速發(fā)展，太湖流域的污染問題引起了學(xué)者和政府的關(guān)注[10]。Lu等[11]研究了太湖水域的重金屬、多氯聯(lián)苯、有機氯農(nóng)藥和PAHs污染，發(fā)現(xiàn)沉積物中的PAHs濃度為24～37 ng·g-1；多氯聯(lián)苯和有機氯農(nóng)藥的濃度范圍分別為1.26～2.41 ng·g-1和0.15～2.06 ng·g-1，遠遠低于PAHs濃度。太湖的整體污染狀況呈現(xiàn)北面高于南面的特點。太湖水域的PAHs生態(tài)風(fēng)險具有地區(qū)差異性，梅梁灣因為受到周邊化工企業(yè)污水排放等的影響，生態(tài)風(fēng)險明顯比貢湖和胥口灣高[12]。然而目前還沒有關(guān)于時間變化的PAHs數(shù)據(jù)。

為此，本文主要針對太湖胥口灣，采集并檢測不同時間段的表層水和沉積物樣本，分析胥口灣PAHs污染的時間和空間變化特點，并對該水域PAHs的污染水平進行生態(tài)風(fēng)險評估，以期為太湖的環(huán)境調(diào)查和環(huán)境變化研究提供更多數(shù)據(jù)參考。

1 材料與方法(Materials and methods)

1.1 試劑和材料

1.2 采樣

于2011年5月、8月和10月分3次采集表層水和沉積物樣品，采樣點位置如圖1所示。同時平行采集表層水。表層水經(jīng)0.45 μm的纖維濾膜過濾以分離出水相和懸浮物，分別測定水相和懸浮相中PAHs的濃度，結(jié)果合并作為表層水中PAHs的濃度。

圖1 太湖胥口灣的采樣位置Fig. 1 The sampling locations in Xukou Bay, Taihu Lake

1.3 樣品處理

水相中加入回收率指示物萘-d8、苊-d8、菲-d10、熒蒽-d10、芘-d10、苯并(a)芘-d12、苯并(ghi)苝-d12，用二氯甲烷進行液液萃取，萃取液合并濃縮后用硅膠/氧化鋁復(fù)合柱(2:1)分離凈化。收集80 mL正己烷/二氯甲烷淋洗液(V/V=7/3)，濃縮氮吹定容后，加入內(nèi)標(biāo)化合物六甲基苯后進行GC-MS測定。

將分離后的懸浮物冷凍干燥后加入回收率指示物并用二氯甲烷進行索氏抽提。抽提液濃縮后用硅膠/氧化鋁復(fù)合柱(2:1)分離凈化。分離凈化和定容過程同水相。

沉積物樣品冷凍干燥后研細過篩。稱取約10 g樣品，加入回收率指示物后進行索氏抽提，收集抽提液并濃縮，分離凈化步驟同懸浮物。

1.4 儀器分析

采用Agilent氣相色譜質(zhì)譜聯(lián)用儀(6890 GC-5975 MSD)分析。色譜柱為HP-5MS毛細管柱(30 m × 0.25 mm × 0.25 μm)；載氣為高純氦，流速1.0 mL·min-1。1 μL無分流手動進樣；進樣口溫度為280 ℃；程序升溫如下：柱始溫80 ℃，保持2 min，3 ℃·min-1升至180 ℃，5 ℃·min-1升至240 ℃并保持1 min，3 ℃·min-1升至290 ℃，保持2 min。采用EI轟擊源，離子源溫度230 ℃；選擇性離子掃描模式檢測；目標(biāo)化合物通過特征離子和標(biāo)樣保留時間比較定性。

1.5 質(zhì)量保證與質(zhì)量控制

水樣和沉積物各帶1個平行樣進行分析，該采樣點分析結(jié)果取平均值。所有樣本的分析過程中均加入了氘代PAHs作為回收率指示物。由于萘-d8的揮發(fā)性強，大部分樣品中其回收率低于60%，因此本文未報道萘的數(shù)據(jù)。其他6種指示物苊-d8、菲-d10、熒蒽-d10、芘-d10、苯并(a)芘-d12和苯并(ghi)苝-d12的回收率分別為：(87.5 ± 16.3)%、(97.7 ± 15.4)%、(98.9 ± 15.1)%、(102.5 ± 16.3)%、(112.3 ± 20.0)%和(109.7 ± 21.6)%。

檢測限(LOD)以低濃度標(biāo)樣響應(yīng)值標(biāo)準(zhǔn)偏差的3.36倍計算，定量檢測限LOQ以LOD的2倍計。統(tǒng)計分析時濃度在LOD和LOQ之間的以1/2 LOQ作為實際濃度，小于LOD的樣品，濃度計為0。使用SPSS 19進行統(tǒng)計分析，統(tǒng)計學(xué)顯著性為P<0.05。

2 結(jié)果(Results)

2.1 濃度水平和組成特征

太湖胥口灣表層水和沉積物中PAHs濃度分別如表1和表2所示。表層水和沉積物中15種PAHs總濃度(15PAHs)的變化范圍為7.2～83 ng·L-1和66～620 ng·g-1干重；15種PAHs年均總濃度為29 ng·L-1(表層水)和218 ng·g-1干重(沉積物)。表層水主要的PAHs污染物為PHE、FLA、FLO和PYR，年均濃度分別為7.9、4.6、4.2和2.8 ng·g-1。沉積物中的PAHs主要污染物為FLA、PYR和CHR，年均濃度分別為32、27和26 ng·g-1，PHE和ANT的濃度均小于20 ng·g-1。表層水的苯并(a)芘毒性當(dāng)量濃度(BaPeq)為0.36～5.6 ng·L-1，沉積物的BaPeq為11～103 ng·g-1干重；其年度平均毒性當(dāng)量濃度分別為2.4 ng·L-1和28 ng·g-1干重。BaPeq的主要貢獻者為DahA、BaP和BaA，沉積物和表層水之間的毒性當(dāng)量濃度差別高于它們的濃度差別。

表1 胥口灣表層水中的PAHs濃度水平

表2 胥口灣沉積物中的PAHs濃度水平

從毒性當(dāng)量濃度組成看，5環(huán)化合物占總濃度的百分比最高，均大于90% (圖2A)。從濃度組成看，表層水中對濃度總量貢獻最多的主要是3環(huán)化合物，但5月水體樣本中濃度百分比最大的是4環(huán)化合物，約占總濃度的43% (圖2A)。沉積物中百分比最高的是4環(huán)化合物，約為44%～48%，和高環(huán)化合物(5+6環(huán))的濃度總量相當(dāng)(圖2B)。

2.2 PAHs的時空分布特征

太湖胥口灣的PAHs污染水平隨時間而波動(圖3A)。豐水期(8月)與平水期(5月)、枯水期(10月)的污染水平具有明顯差異(Mann-Whitney U檢驗，表層水P = 0.01～0.033，沉積物P = 0.000～0.039)。表層水的豐水期濃度明顯高于平/枯水期，沉積物的情況剛好相反，豐水期污染水平略低。平水期和枯水期的污染濃度之間無顯著性差異Mann-Whitney U檢驗，表層水P = 0.514，沉積物P = 0.291。

將采樣點分成湖區(qū)(XK-1，XK-2，XK-3，XK-6和XK-10)和湖岸(XK-4，XK-5，XK-7，XK-8，XK-9，XK-11和XK-12)，比較兩者的差別(圖3B和圖3C)，發(fā)現(xiàn)湖區(qū)和湖岸的PAHs濃度之間無顯著差異，特別是平枯水期的污染濃度之間(獨立樣本T檢驗，表層水P = 0.184～0.859，沉積物P = 0.105～0.179)。豐水期沉積物中PAHs的濃度差異性也不大(獨立樣本T檢驗，P=0.129)；但表層水的湖區(qū)濃度顯著高于湖岸(獨立樣本T檢驗，P = 0.011)。

2.3 生態(tài)風(fēng)險評估

利用加拿大魁北克省的沉積物質(zhì)量標(biāo)準(zhǔn)對太湖胥口灣PAHs污染開展初步的生態(tài)風(fēng)險評價。該標(biāo)準(zhǔn)提供了5個濃度閾值，分別為生態(tài)效應(yīng)罕有發(fā)生濃度值(the rare effect level，REL)、臨界發(fā)生濃度值(the threshold effect level, TEL)、偶然發(fā)生濃度值(the occasional effect level, OEL)、可能發(fā)生濃度值(the probable effect level, PEL)和頻繁發(fā)生濃度值(the frequent effect level, FEL)[13]。閾值范圍分別為REL(3.3～47 ng·g-1)、TEL(5.9～110 ng·g-1)、OEL (21 ～450 ng·g-1)、PEL(89～2 400 ng·g-1)和FEL ( 200～4 900 ng·g-1)。該閾值對每種PAH都有濃度要求，本研究中，沉積物PAHs只要有一種污染物濃度超標(biāo)即視為污染水平整體超標(biāo)。3個采樣期12個采樣點PAHs帶來的生態(tài)風(fēng)險評估結(jié)果如圖4所示。圖中可以看出大部分采樣點都處于REL～TEL生態(tài)風(fēng)險水平范圍內(nèi)，處于較低的污染水平。但是個別采樣點和特定采樣期的生態(tài)風(fēng)險略高，個別點主要分布在湖岸地區(qū)。XK-8和XK-12更是胥口灣重要的水源地。平水期5月也是PAHs生態(tài)風(fēng)險高的頻發(fā)期，沉積物PAHs污染水平相對較高。

圖2 表層水(A)和沉積物(B)中PAHs的組成分布Fig. 2 Compositions of PAHs in surface water (A) and sediments (B)

圖3 PAHs的時空分布特征 注：A，不同采樣時間表層水和沉積物中的PAHs濃度；B，不同采樣時間湖區(qū)和湖岸表層水中的PAHs濃度；C，不同采樣時間湖區(qū)和湖岸沉積物中的PAHs濃度。Fig. 3 The spatial and temporal distribution characteristics of PAHs Note: A, The concentrations of PAHs in surface water and sediment with different sampling time; B, The concentrations of PAHs in lake and nearshore in surface water with different sampling time; C, The concentrations of PAHs in lake and nearshore in sediment with different sampling time.

圖4 沉積物中PAHs生態(tài)風(fēng)險的時空變化特征 注：A，5月；B，8月；C，10月。Fig. 4 The spatial and temporal characteristics of the ecological risk assessment of PAHs in sediments Note: A, May; B, August; C, October.

3 討論(Discussion)

低中環(huán)化合物(3和4環(huán))是表層水的主要PAHs污染物，而沉積物中主要是4環(huán)的FLA、PYR和CHR。這種組成分布特征與許多文獻結(jié)果一致[14-15]。東北渾河沉積物中FLA和PYR的濃度水平較高[14]，渤海沿岸地區(qū)的河流PAHs研究結(jié)果也是如此[15]。對于PAHs來說，它們的KOW值隨環(huán)數(shù)的增加而增大，高環(huán)數(shù)化合物在水中溶解度的減小，使得它們主要沉降蓄積在沉積物中，而低環(huán)數(shù)的PAHs更容易隨水相遷移或揮發(fā)至大氣。

表3 不同地區(qū)PAHs污染水平比較

圖5 PAHs的來源解析Fig. 5 The source analysis of PAHs

從污染水平來說，太湖胥口灣表層水的PAHs污染水平不高(表3)。太湖胥口灣的污染濃度明顯小于中國北部地區(qū)諸多河流。如東北松花江表層水的PAHs高達934 ng·L-1，太湖胥口灣的水體平均濃度是它的1/30[16]。長江三峽段和浙江舟山海域的污染程度也高于本研究區(qū)域[17-18]。太湖胥口灣沉積物PAHs的濃度水平和千島湖(258～906 ng·g-1)、鄱陽湖(200～400 ng·g-1)的結(jié)果接近[19-20]，與青海湖處于同一數(shù)量級但略低[35]。上海東部的滴水湖建成時間只有10多年，湖體沉積物的濃度水平稍低于本研究的數(shù)據(jù)[22]。與密歇根湖及阿根廷湖相比，胥口灣的整體污染程度是它們的3～30倍[23-24]。胥口灣位于整個太湖流域的東南角，湖面比較開闊；胥口灣靠近太湖風(fēng)景區(qū)，附近工廠和工業(yè)排放較少，水域整體的污染水平相對較低。

胥口灣的PAHs污染具有時間差異性。8月為豐水期，全年雨水量較集中于該時期。大量的外來徑流輸入和大氣沉降為湖區(qū)環(huán)境增加了PAHs輸入量，造成表層水濃度的提高。豐水期的風(fēng)浪潮流作用及船舶運輸?shù)仍斐珊w沉積物的再懸浮，PAHs從再懸浮顆粒上的解吸釋放也會提高表層水的污染水平[25]。湖泊沉積物的再懸浮又會影響沉積物，引起豐水期沉積物污染濃度的下降。豐水期湖區(qū)和湖岸的空間差異性特點也符合輸入和再懸浮過程作用的影響效果。豐水期表層水為湖區(qū)大于湖岸；沉積物為湖區(qū)略高；而平、枯水期的地區(qū)差異性不明顯。

特征化合物比值法可對環(huán)境PAHs的來源進行解析[25]。ANT/(ANT+PHE)小于0.1通常意味著石油燃料類排放來源，其值大于0.1則主要是燃燒來源的影響；FLA/(FLA+PYR)小于0.5則PAHs主要來源于石油燃料類排放，而大于0.5則主要來源于木材和煤的燃燒[27]。本研究結(jié)果顯示，表層水的ANT/(ANT+PHE)比值和FLA/(FLA+PYR)比值分別為0.01～0.1和0.52～0.95；沉積物的ANT/(ANT+PHE)比值為0.06～0.24，F(xiàn)LA/(FLA+PYR)比值為0.49～0.82 (圖5A)。說明胥口灣表層水中PAHs主要來源于石油和燃燒來源，而沉積物中PAHs主要來源于煤和木材燃燒，這和Shi等[28]的研究結(jié)果相同。但是，IcdP/IcdP+BghiP和BaA/BaA+CHR值小于0.2時，則認為是石油類污染，當(dāng)IcdP/IcdP+BghiP大于0.5或BaA/BaA+CHR大于0.35則認為是燃燒來源[29]。從圖5B中可以看出，大部分表層水中的PAHs是石油和燃燒來源的混合，而沉積物中的PAHs可能大部分是燃燒來源，含有少量的混合源，這也與ANT/(ANT+PHE)和FLA/(FLA+PYR)比值分析結(jié)果一致。這說明太湖繁榮的水上交通對太湖PAHs的污染有重要貢獻。

生態(tài)風(fēng)險評價結(jié)果如圖4所示，太湖胥口灣沉積物的PAHs污染水平基本處于生態(tài)效應(yīng)罕見發(fā)生濃度范圍和臨界發(fā)生濃度范圍之間，少部分采樣點還達到偶爾發(fā)生濃度值，這些點主要集中在湖岸區(qū)域，正是由于內(nèi)陸周邊工業(yè)企業(yè)的發(fā)展，PAHs隨地表徑流排入湖，湖岸地區(qū)的生態(tài)風(fēng)險相對高。平水期5月份，PAHs能夠較穩(wěn)定地吸附在沉積物表面，此時的沉積物污染水平相對其他時期較高。但是整體來說，太湖胥口灣的生態(tài)風(fēng)險低。

4 結(jié)論(Conclusions)

太湖胥口灣表層水和沉積物中PAHs的污染水平較低。3和4環(huán)PAHs是表層水的重要污染物，而4環(huán)化合物是沉積物的主要污染物，5環(huán)化合物對毒性當(dāng)量濃度的貢獻最大。時間變化而言，豐水期表層水濃度偏高，沉積物濃度較低；平枯水期的差別不顯著。不同區(qū)域的PAHs污染差異性較小，除豐水期表層水中PAHs的湖區(qū)組濃度顯著高于湖岸組外，其他情況下湖區(qū)和湖岸的污染濃度總體比較相近。PAHs特征化合物比值分析表明，胥口灣沉積物中PAHs主要來源于煤和木材燃燒，表層水則是石油和燃燒的混合源。太湖胥口灣的PAHs污染程度不高，只有湖岸的少部分采樣點及平水期5月的生態(tài)風(fēng)險略高，整體處于低生態(tài)風(fēng)險。

[1] Rodrigo S, William O, Martha P, et al. Presence of PAHs in water and sediments of the Colombian Cauca River during heavy rain episodes, and implications for risk assessment [J]. Science of the Total Environment, 2016, 540: 455-465

[2] Fernandez P, Vilanova R M, Martinez C, et al. The historical of record of atmospheric pyrolytic pollution over Europe registered in the sedimentary PAH from remote mountain lake [J]. Environmental Science & Technology, 2000, 34(10): 1906-1913

[3] Yu W W, Liu R, Wang J W, et al. Source apportionment of PAHs in surface sediments using positive matrix factorization combined with GIS for the estuarine area of the Yangtze River, China [J]. Chemosphere, 2015, 134: 263-271

[4] Shi Z, Tao S, Pan B, et al. Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China [J]. Environmental Pollution, 2007, 146(2): 492-500

[5] Men B, He M C, Tan L, et al. Distributions of polycyclic aromatic hydrocarbons in the Daliao River Estuary of Liaodong Bay, Bohai Sea (China) [J]. Marine Pollution Bulletin, 2009, 58(6): 818-826

[6] Zhao X S, Ding J, You H, et al. Spatial distribution and temporal trends of polycyclic aromatic hydrocarbons (PAHs) in water and sediment from Songhua River, China [J]. Environmental Geochemistry and Health, 2014, 36(1): 131-143

[7] Ana C R, Julián M B, José L S, et al. Coexisting sea-based and land-based sources of contamination by PAHs in the continental shelf sediments of Coatzacoalcos River discharge area (Gulf of Mexico) [J]. Chemosphere, 2016, 144: 591-598

[8] 程家麗, 黃啟飛, 魏世強, 等. 我國環(huán)境介質(zhì)中多環(huán)芳烴的分布及其生態(tài)風(fēng)險[J]. 環(huán)境工程學(xué)報, 2007, 1(4): 138-144

Chen J L, Huang Q F, Wei S Q, et al. Distribution and ecological risk of PAHs in the environmental media of China [J]. Chinese Journal of Environmental Engineering, 2007, 1(4): 138-144 (in Chinese)

[9] Qiao M, Wang C X, Huang S B, et al. Composition, sources, and potential toxicological significance of PAHs in the surface sediments of the Meiliang Bay, Taihu Lake, China [J]. Environment International, 2006, 32(1): 28-33

[10] Zhong W J, Wang D H, Xu X W, et al. Screening level ecological risk assessment for phenols in surface water of the Taihu Lake [J]. Chemosphere, 2010, 80(9): 998-1005

[11] Lu G H, Ji Y, Zhang H Z, et al. Active biomonitoring of complex pollution in Taihu Lake with Carassius auratus [J]. Chemosphere, 2010, 79(5): 588-594

[12] Guo G H, Wu F C, He H P, et al. Characterizing ecological risk for polycyclic aromatic hydrocarbons in water from Lake Taihu, China [J]. Environmental Monitoring and Assessment, 2012, 184(11): 6815-6825

[13] Environment Canada and Ministère du développement durable, de I’ Environment et des Parcs du Québec. Criteria for the Assessment of Sediment Quality in Quebec and Application Frameworks: Prevention, Dredging and Remediation [S]. Québec: Library and Archives Canada Cataloguing in Publication, 2007: 1-39

[14] Liu Z Y, He L X, Lu Y Z, et al. Distribution, source, and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Hun River, northeast China [J]. Environmental Monitoring and Assessment, 2015, 187(5): 280-290

[15] Wang Z, Wang Y, Ma X D, et al. Probabilistic ecological risk assessment of typical PAHs in coastal water of Bohai Sea [J]. Polycyclic Aromatic Compounds, 2013, 33(4): 367-379

[16] Zhao X S, Ding J, You H. Spatial distribution and temporal trends of polycyclic aromatic hydrocarbons (PAHs) in water and sediment from Songhua River, China [J]. Environmental Geochemistry and Health, 2014, 36(1): 131-143

[17] Dominik D, Wang J X, Hu W, et al. PAH distribution and mass fluxes in the Three Gorges Reservoir after impoundment of the Three Gorges Dam [J]. Science of the Total Environment, 2014, 491: 123-130

[18] 江敏, 梅衛(wèi)平, 阮慧慧, 等. 舟山近海水體和沉積物中多環(huán)芳烴分布特征[J]. 環(huán)境科學(xué), 2014, 35(7): 2673-2679

Jiang M, Mei W P, Ruan H H, et al. Distribution of polycyclic aromatic hydrocarbons in the coastal water and sediments of Zhoushan [J]. Environmental Science, 2014, 35(7): 2673-2679 (in Chinese)

[19] 張明, 唐訪良, 吳志旭, 等. 千島湖表層沉積物中多環(huán)芳烴污染特征及生態(tài)風(fēng)險評價[J]. 中國環(huán)境科學(xué), 2014, 34(1): 253-258

Zhang M, Tang F L, Wu Z X, et al. Characteristics and ecological risk assessment of PAHs in surface sediments of Qiandao Lake [J]. China Environmental Science, 2014, 34(1): 253-258 (in Chinese)

[20] Lu M, Zeng D C, Liao Y, et al. Distribution and characterization of organochlorine pesticides and polycyclic aromatic hydrocarbons in surface sediment from Poyang Lake, China [J]. Science of the Total Environment, 2012, 433: 491-497

[21] Roozbeh M, Mehdi M, Iraj F, et al. Source identification of polycyclic aromatic hydrocarbons (PAHs) in sediment samples from the northern part of the Persian Gulf, Iran [J]. Environmental Monitoring and Assessment, 2014, 186(11): 7387-7398

[22] Faiqa A, Jabir H S, Riffat N M, et al. Occurrence of polycyclic aromatic hydrocarbons in the Soan River, Pakistan: Insights into distribution, composition, sources and ecological risk assessment [J]. Ecotoxicology and Environmental Safety, 2014, 109: 77-84

[23] Chizhova T, Hayakawa K, Tishchenko P, et al. Distribution of PAHs in the northwestern part of the Japan Sea [J]. Deep Sea Research II, 2013, 86-87: 19-24

[24] Yilmaz A, Karacik B, Henkelmann B, et al. Use of passive samplers in pollution monitoring: A numerical approach for marinas [J]. Environment International, 2014, 73: 85-93

[25] 王曉慧, 畢春娟, 韓景超, 等. 再懸浮過程中河流底泥PAHs遷移與釋放[J]. 環(huán)境科學(xué), 2014, 35(6): 2185-2192

Wang X H, Bi C J, Han J C, et al. Migration and release of PAHs in river sediments during resuspension process [J]. Environmental Science, 2014, 35(6): 2185-2192 (in Chinese)

[26] Larsen R K, Baker J E. Source apportionment of polycyclic aromatic hydrocarbons in the urban atmosphere:A comparison of three methods [J]. Environmental Science & Technology, 2003, 37(9): 1873-1881

[27] Shao Y X, Wang Y X, Xu X Q, et al. Occurrence and source apportionment of PAHs in highly vulnerable karst system [J]. Science of the Total Environment, 2014, 490: 153-160

[28] Shi L Q, Cheng J G, Wu J J. Polycyclic aromatic hydrocarbons in surface sediments of northern Taihu Lake and the coupling with the environment [C]. Xi'an: Advanced Materials Research, 2011: 706-711

[30] Manodori L, Gambaro A, Piazza R, et al. PCBs and PAHs in sea-surface microlayer and sub-surface water samples of the Venice Lagoon (Italy) [J]. Marine Pollution Bulletin, 2006, 52(2): 184-192

[31] Zhang Y, Yu H J, Xi B, et al. Levels, sources, and potential ecological risks of polycyclic aromatic hydrocarbons (PAHs) in a typical effluent-receiving river (Wangyang River), North China [J]. Arabian Journal of Geosciences, 2015, 8: 6535-6543

[32] Zhang Q, Pei G X, Liu G Y, et al. Distribution and photochemistry of polycyclic aromatic hydrocarbons in the Baotou section of the Yellow River during winter [J]. Archives of Environmental Contamination and Toxicology, 2015, 69: 133-142

[33] Mozeto A A, Yamada T M, Morais C R D, et al. Assessment of organic and inorganic contaminants in sediments of an urban tropical eutrophic reservoir [J]. Environmental Monitoring and Assessment, 2014, 186(2): 815-834

[34] Fehmi K, Laurence A, Agung D S, et al. Distribution and risk assessment of hydrocarbons (aliphatic and PAHs), polychlorinated biphenyls (PCBs), and pesticides in surface sediments from an agricultural river (Durance) and an industrialized urban lagoon (Berre lagoon), France [J]. Environmental Monitoring and Assessment, 2015, 187: 591-596

[35] 郭建陽, 廖海清, 張亮, 等. 青海湖沉積物中多環(huán)芳烴的沉積記錄[J]. 生態(tài)學(xué)雜志, 2011, 30(7): 1467-1472

Guo J Y, Liao H Q, Zhang L, et al.The sedimentary records of polycyclic aromatic hydrocarbons in Sediments of Qinghai Lake [J]. Chinese Journal of Ecology, 2011, 30(7): 1467-1472 (in Chinese)

[36] Huang L, Sergei M, Chernyak S A, et al. PAHs (polycyclic aromatic hydrocarbons), nitro-PAHs, and hopane and sterane biomarkers in sediments of southern Lake Michigan, USA [J].Science of the Total Environment, 2014, 487: 173-186

[37] Laitano M V, Castro í B, Costa P G, et al. Butyltin and PAH contamination of Mar del Plata Port (Argentina) sediments and their influence on adjacent coastal regions[J]. Bulletin of Environmental Contamination and Toxicology, 2015, 95: 513-520

[38] 郭雪, 畢春娟, 陳振樓, 等. 滴水湖及其水體交換區(qū)沉積物和土壤中PAHs的分布及生態(tài)風(fēng)險評價[J]. 環(huán)境科學(xué), 2014, 35(7) : 2664-2671.

Guo X, Bi C J, Chen Z L, et al. Distribution and ecological risk assessment of PAHs in sediments and soils in Dishui Lake and its water exchange zone [J].Environmental Science, 2014, 35(7) : 2664-2671 (in Chinese)

◆

The Contamination Levels of Polycyclic Aromatic Hydrocarbons in Surface Water and Sediments in Xukou Bay of Taihu Lake and the Associated Ecological Risk

Li Xiaojing1, Yu Yuling1, Ma Li1, Zeng Xiangying2, Yu Yingxin1, Zhang Xiaolan1,*

1. Institute of Environmental and Chemical Engineering, Environmental Pollution and Health Research Institute, Shanghai University, Shanghai 200444, China 2. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510000, China

Received 6 December 2015 accepted 29 January 2016

Polycyclic aromatic hydrocarbons (PAHs), a class of condensed ring compounds, are widely detected in various environmental matrices. Because of their adverse effects on human health and ecological environment, 16 PAHs were listed as priority controlled pollutants by the United States Environmental Protection Agency. Studies showed that PAHs were the main contaminants in Taihu Lake. It is important to investigate the quality of water in Taihu Lake where is an important hydrographic net and urban drinking water supply in East China. The investigation is also very important to improve the aquatic ecosystem qualities and human health of the coastal residents. In the present study, the spatial and temporal variations of PAHs in surface water and sediments in Xukou Bay, Taihu Lake, were investigated. The results showed that the total concentrations of PAHs ranged from 7.2 to 83 ng·L-1for surface water, and from 66 to 620 ng·g-1dry weight for sediments. The average annual concentrations of PAHs in the two matrices were 29 ng·g-1and 218 ng·g-1dry weight, respectively. The mean benzo(a)pyrene toxicity equivalent concentrations (BaPeq) were 2.4 ng·g-1and 28 ng·g-1dry weight in them, respectively. The main pollutants were fluoranthene, pyrene, and chrysene in sediments, while benzo(a)pyrene and dibenz(a,h)anthracene were the most abundant compounds when BaPeqwas considered. The concentrations of 4-ring PAHs accounted for 44%～48% of the total PAHs in sediments, and 5-ring compounds contributed to more than 90% of the total BaPeq. The ratio analysis of the characteristic PAHs showed that PAHs in sediments in Xukou Bay are mainly from burning coal and wood, while PAHs in surface water mainly have fossil fuel and combustion sources. Relatively higher concentrations in surface water and lower concentrations in sediments were observed during the flood season (August). There was no significant difference of the PAH contamination between dry season and ordinary level season. According to the Canadian sediment environmental quality standards, the ecological risks of PAHs in Xukou Bay were low. The spatial and temporal ecological risks showed that the locations with higher ecological risks were mainly at the nearshore. Higher ecological risks of PAHs in sediments might be observed during the ordinary level season (in May), generally.

polycyclic aromatic hydrocarbons; surface water; sediments; ecological risk; spatial and temporal variation; Taihu Lake

10.7524/AJE.1673-5897.20151206002

國家自然科學(xué)基金項目(21277087)；中科院重點實驗室開放基金(SKLEAC201411)

李曉靜(1990-)，女，研究生在讀，研究方向有機污染物遷移轉(zhuǎn)化行為研究，E-mail: lxj1123@shu.edu.cn

*通訊作者(Corresponding author)， E-mail: zhangxiaolan@staff.shu.edu.cn

2015-12-06 錄用日期：2016-01-29

1673-5897(2016)2-547-09

X171.5

A

簡介：張曉嵐(1967—)，女，博士，副教授，主要研究方向環(huán)境污染分析，發(fā)表學(xué)術(shù)論文30余篇。

李曉靜, 于玉玲, 馬莉, 等. 太湖胥口灣表層水和沉積物中多環(huán)芳烴的濃度水平及生態(tài)風(fēng)險[J]. 生態(tài)毒理學(xué)報，2016, 11(2): 547-555

Li X J, Yu Y L, Ma L, et al. The contamination levels polycyclic aromatic hydrocarbons in surface water and sediments in Xukou Bay of Taihu Lake and the associated ecological risk [J]. Asian Journal of Ecotoxicology, 2016, 11(2): 547-555 (in Chinese)