| Kelp(Laminaria japonica)and Laver(Porphyra)are important large scale economic cultured seaweed species of China,which are also the main export seafood in China,and it is very popular among customers at home and abroad.Along with our country industrialization and the rapid development,industrial three wastes have been discharged into the offshore areas.The content of heavy metals and other metal elements has attracted people’s great concern.The heavy metal content is also the important indicators of our seaweed products quality control.Studying on the levels of metallic elements and the risk assessment of heavy metals pollution,guiding the healthy and safety comsumption of kelp and laver,promoting the industry development,enlarging the export scale and export volume,and providing the scientific means for heavy metals risk management have very important significance.The main results and innovations are as follows:1.The contents of 15 metals in kelp and laver sold on the market of the four sea area of China had been analyzed.The results showed that the mean concents for Cd,Cr,Pb,Hg,As,In As,Cu,Co,Ni,Se,Mn,Fe,Zn,Ag,Ba and Cs in kelp and laver were 0.48 mg/kg and 2.5 mg/kg,3.81 mg/kg and 1.71 mg/kg,0.71 mg/kg and 1.06 mg/kg,46.61 μg/kg and 9.50 μg/kg,43.85 mg/kg and 36.86 mg/kg,and 0.240 mg/kg,2.54 mg/kg and 15.22 mg/kg,0.15 mg/kg and 0.28 mg/kg,1.93 mg/kg and 2.45 mg/kg,0.17 mg/kg and 0.15 mg/kg,15.70 mg/kg and 46.37 mg/kg,300.37 mg/kg and 4700 mg/kg,0.15 mg/kg and 0.28 mg/kg,19.93 mg/kg and 40.18 mg/kg,0.03 μg/kg and 149.78 μg/kg,17.08 mg/kg and 7.93 mg/kg,0.07 mg/kg and 0.07 mg/kg,respectively.The exceeding rates of Pb and In As in kelp and laver were 16.13% and 33.54%,0 and 1%,respectively.The content values of total Hg in kelp and laver were all lower than the standard limited value(0.5 mg/kg)for Methyl-Hg in seaweed.In our country,the limited standard value for Cr in kelp and laver has yet been established.If the standard limited value(2.0 mg/kg)for Cr in aquatic animals and its products set in GB2762-2012 was used,the exceeding rates for Cr in kelp and laver were 42.52% and 17.87%,respectively.There are some differences between kelp and laver in the content of metallic elements,especially,the contents of Hg,Mn,Fe,Cu,Zn,Ag,Cd in laver were obviously higher than that in kelp.The contents of Cr and As in kelp were higher than that in laver,and the levels of Co,Ni and Se in kelp were close to that in laver.The distribution of metals in kelp and laver was directly related to the biological characteristics and the concentration of elements in the sea area.Cd and As pollution in dried kelp of Yantai,Hg and Pb pollution in dried kelp of Wenzhou,and Cr pollution in dried kelp of Shantou were serious.Cr and Hg containmination in dried laver of Fuzhou,Cd containmination in dried laver of Taizhou,As containmination in dried laver of Lianyungang,and Pb containmination were serious.2.Three methods for analyzing Hg species,As species and Se species in kelp,laver and other aquatic products were established by HPLC-ICP-MS.The recoveries for Hg2+,Methyl-Hg and Ethyl-Hg spiked in kelp,laver and fish muscle were 78.84%-90.72%,84.20%-92.96% and 79.84%-88.60%,respectively,and the relative standard deviations were 3.43%-7.64%,3.58%-5.61% and 3.93%-6.72%,respectively.The detection limits for Hg2+,Methyl-Hg and Ethyl-Hg were 0.11,0.16 and 0.19 μg/L,respectively.The recovery rates for arsenite(As(Ⅲ)),arsenate(As(Ⅴ)),monomethylarsonic acid(MMA),dimethylarsinic acid(DMA),arsenocholine(As C),and arsenobetaine(As B)in kelp and laver were 84.51%-94.25% and 84.38%-95.25% with the relative standard deviations of 3.41%-7.18% and 2.64%-6.33%,respectively.The detection limits for As(Ⅲ),As(Ⅴ),MMA,DMA,As C and As B were 0.3,0.5,0.7,0.6,0.5 and 0.3 μg/L.The recoveries for 5 Se speices fortified in kelp,laver and tea were 78%-95.45%,85.0%-97.7% and 82.0%-98.2% with the relative standard deviations of 1.67%-6.53%,2.62%-5.41% and 2.54%-5.25%,respectively.The detection limits for selenite,selenate,selenomethionine,selenocystine and methylselenocysteine were 0.8、0.4、0.6、0.3、0.4 μg/L,respectively.Arsenosugars were separated and identified in kelp and laver by high performance liquid chromatography coupled to Obitrap Fusion mass spectrometry(HPLC-Obitrap Fusion MS).The results show that 3 kinds of arsenosugars(Phosphate arsinoylriboside(PO4-sug),Glycerol arsinoylriboside(Gly-sug)and Sulfonate arsinoylriboside(SO3-sug))are found in kelp,and 2 kinds of arsenosugars are found in laver(PO4-sug and Gly-sug).3.The intake of kelp and laver from 348 residents(3 to 65 year old)in China was investigated,and heavy metals in kelp and laver dietary exposure assessment of was carried out.The average intake and average maximum intake per time for kelp are 40.59 g and 79.57 g(wet weight),respectively.The average intake and average maximum intake per time for laver were 21.88 g and 51.60 g(dried weight),respectively.The average annual consumption for kelp and laver are 66.7 and 56.8 times,respectively.The average maximum estimated daily intake(MEDI)for Cd from kelp and laver by children,young adults and elser residents were 0.692E-04 mg/(kg·d)and 3.565E-04 mg/(kg·d),0.881E-04 mg/(kg·d)and 4.330E-04 mg/(kg·d),0.649E-04 mg/(kg·d)and 2.894E-04 mg/(kg·d),respectively.From kelp and laver Cr’s average MEDI by children,young adults and elser residents were 5.379E-04 mg/(kg·d)and 2.284E-04 mg/(kg·d),6.818E-04 mg/(kg·d)and 2.787E-04 mg/(kg·d),5.693E-04 and 1.859E-04,respectively.From kelp and laver Pb’s average MEDI by children,young adults and elser residents were 1.054E-04 mg/(kg·d)and 1.277E-04 mg/(kg·d),1.328E-04 mg/(kg·d)and 1.551E-04 mg/(kg·d),0.977E-04 mg/(kg·d)and 1.036E-04 mg/(kg·d),respectively.From kelp and laver Hg’s average MEDI by children,young adults and elser residents were 7.246E-06 mg/(kg·d)and 1.196E-06 mg/(kg·d),9.249E-06 mg/(kg·d)and 1.431E-06 mg/(kg·d),6.820E-06 mg/(kg·d)and 0.956E-06 mg/(kg·d),respectively.From kelp and laver In As’ s average MEDI by children,young adults and elser residents were 0.591E-04 mg/(kg·d)and 0.320E-04 mg/(kg·d),0.752E-04 mg/(kg·d)and 0.389E-04 mg/(kg·d),0.554E-04 mg/(kg·d)and 0.260E-04 mg/(kg·d)respectively.The exposure level of Cd and Cr were high,and Pb’s exposure level was lower than Cd and Cr.The exposure level of Hg and In As was very low.The order of heavy metals exposure in different age populations was young adults> children> elser.Female populations’ heavy metals exposure amount from laver was higher than male population.The exposure amount of Cd and Pb from laver was higher than that from kelp by residents in China.The exposure amount of Cr and Hg from kelp was higher than that from laver by residents in China.4.The heavy metals risk from kelp and laver in China had been described using non-parametric probability assessment.The results showed that the hazard quotients(HQ)of Cd,Cr,Pb,Hg and In As from kelp and laver were less than 1.On the whole,it was safe.The order of HQ was young adults>children>elser.The descendent sequences of HQ from kelp and laver were Cd>Cr>Pb>Ion As>Hg and Cd>Pb>Cr>Ion As>Hg.The HQ of Cd from laver was more than that from kelp,and the HQ of Cr and Hg from kelp was more than that from laver,and Pb’s HQ from laver was close to that from kelp.The order of Cr,Pb and Hg HQ was all from kelp by male populations>from kelp by female populations>from laver by female populations>from laver by male populations.The HQ of Cd and In As from laver by female populations was higher than that by male populations.Cd’s HQ from kelp by male children and male elser was more than that by female children and female elser,however,it by female young adults was more than male adults.When combined effects of Cd,Cr,Pb,Hg and In As from kelp and laver,Children,young adults and elser’s accumulated HQ and MHQ were 0.34 and 0.72,0.39 and 0.89,0.28 and 0.61,respectively.From that,it can seen that young adults’ s accumulated MHQ of 5 heavy metals from kelp and laver was 0.89,which is close to the risk value of 1 and it should be paid attention.From the point of view of the contribution rates of different heavy metals from kelp and laver,the largest contributor was Cd,and its contribution rate was 69.7%.The contribution rates from Cr,Pb,In As and Hg were 14.0%,9.4%,4.5% and 2.3%,respectively.In China,Cd and Cr were at higher risk than other heavy metal elemnets in kelp and laver.Pb,In As and Hg have low risk. |
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