| Mobile phones are typical representatives of small communication devices.According to statistics,global mobile phone subscriptions have reached 7 billion by 2017.Technology innovation has been gradually shortened its service life.Obviously,waste mobile phones(WMPs)will increase rapidly.WMPs contain a lot of hazardous substances,if it is treated improperly,it would threaten human health and environment.Therefore,local,national,and international governments are enforicing stricter and stricter regulations to protect nature and human health.At the same time,technology innovation will inevitably affect the materials and producing processes of mobile phones.Unfortunately,there are few studies about if technology and policies would affect the basic property and potential impact on human health and environment of WMPs.Typical WMPs for nearly ten years(between 2002 and 2013)were collected,analyzed the impact of technology and policies on metal content and characteristic by Toxicity Characteristic Leaching Procedure(TCLP),bioavailability and BCR method.The impact of technology and policies on human toxicity and ecotoxicity were analyzed by USEtox model.The significant results are obtained as following:1.On the whole,metal content of the 36 WMPs,Fe,Cu and Al are the most abundant metals,with an average of 34335,28351,and 27567 mg/kg,representing about 20%,16%,and 16%of the total metallic content.Cr,Zn,Ni,Ba,Co,Mg,and Sn account for 12.83,7.73,10,1.38,6.26,5.45,and 2.98%of the total metal content,respectively.The contents of Ag,As,Au,Mo,Pb,Pd,Se,Sb,Tl,and V are less than 1%.Be and Cd are not detected in all WMPs.Total metal content of WMPs increases from 125073 mg/kg in 2002 to 237316 mg/kg in 2007,then decreases after 2007,which is 174745 mg/kg in 2013.The results highlight that regulations do not have significant impact on its total metal content,while technology innovation records a stronger impact.2.Metal characteristic of WMPs was analyzed by three methods.TCLP leaching of As and Cd are below the detection limit,and Ag,Ba,and Cr are within TCLP limits.Metals with high bioavailability are Co,Zn,Al,Fe,Cu,Ba,Pb,Ni,and Sn,which are 142.47,113.82,89.63,88.7,74.09,28.77,24.31,17.71,and 14.57 mg/kg,respectively.Total metal bioavailability is 380 mg/kg in 2003,591 mg/kg in 2007,and 1062 mg/kg in 2013,performing a rising tendency.Distribution of metal chemical form:Mg,Co,and A1 soluble acid content is 6420,4774,and 3607 mg/kg;Al,Fe,and Mg reducing content is 13522,6739,and 5927 mg/kg;Cu,Al,and Fe oxidizable content is 12357,8625,and 7977 mg/kg;Fe,Cu,and Cr residual content is 257827,86073,and 61000 mg/kg,respectively,Ag,Ba,Be,Cr,Cu,Fe,Ni,Sb,Sn,and V are mainly in the form of residual state,and for other metals Al,As,Au,Pd,Co,Mg,Tl,Zn,and Pb which residue state is less.3.Human toxicity and ecotoxicity of metals in WMPs were analyzed.Cu poses the most significant ecotoxicity risk,which is 52344 to 123937 PAF·m3·day·kg-1,then A1(from 18236 to 81096 PAF·m3 day·kg-1)and Ni(from 10047 to 30070 PAF·m3·day·kg-1).The ecotoxicity contribution rates of Cu,Al,and Ni is 58,28,10%,respectively.Cr shows the most significant risk for both cancerous and non-cancerous diseases,ranging from 1.16×10-4 to 2.57×10-4 cases/kgemitted and from 1.11×10-4 to 2.46×10-4 cases/kgemitted,respectively.The sum of Cr,Ag,Ni,Pb,and As human health toxicity(carcinogenic and non-carcinogenic)contribution rate is higher than 99%.From 2002 to 2013,the ecotoxicity of WMPs increases,while human health toxicity(whether carcinogenic and non-carcinogenic)presents a "three-stage" phenomenon.From 2002 to 2006,the risk is minimal;2007 to 2009,the risk is the highest;2010 to 2013 is the intermediate period.Additionally,we demonstrate that WMPs toxicity increases with time,and technological innovations and regulation development does not show a positive impact on WMPs toxicity. |
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