贵州草海湿地不同水深梯度下沉积物铁形态分布特征

为了研究水文条件对湿地沉积物中铁赋存形态分布的影响,采用Tessier五步连续提取法对贵州草海不同水深梯度下沉积物中铁各形态进行研究.结果表明,草海湿地沉积物中总铁含量在22.8—46.2 g·kg~(-1)之间,平均值为37.06 g·kg~(-1),随着水深升高整体呈下降趋势.草海湿地沉积物中,各形态铁含量大小为残渣态(RES-Fe:7.16—41.22 g·kg~(-1))有机结合态(OM-Fe:1.68—13.94 g·kg~(-1))铁锰氧化物结合态(RED-Fe:2.29—6.96 g·kg~(-1))碳酸盐结合态(CARB-Fe:0.004—0.095 g·kg~(-1))可交换态(EXC-Fe:0.002—0.004 g·kg~(-1));各形态铁含量对水深变化响应不一致,RES-Fe、EXC-Fe和Tot-Fe含量随水深加深而减少,RED-Fe和OM-Fe含量随水深加深而增高,CARB-Fe含量无明显变化规律;水文条件影响铁形态组成,季节性积水的S1和S2样点铁含量较高,仅以RES-Fe为主,占总量的87%—91%,而积水较深且长期淹水的S3和S4铁含量较低,以OM-Fe和RES-Fe为主,二者之和占总量的81%—85%.湿地沉积物中铁含量及其形态组成分布会因为水深变化而不同,铁的生物有效性也会因此发生改变,抬升水位有利于提高铁的生物有效性.     

湘江排污口环境中砷的污染特征及潜在生态风险

对排污口砷的形态进行分析有助于从源头上找出水环境中砷污染的原因,为评估生态系统潜在风险及实施生态管理等提供科学依据。采用连续分级提取法研究了湘江下游某排污口表层沉积物(0~10 cm)中各形态砷的分布特征并对植物、水样中的砷进行了测定,其结果表明:排污口0~1 km的范围内沉积物中总砷的平均质量分数为1 373 mg?kg~(-1),各形态砷占比顺序为残渣态(72.74%~78.76%)晶形结合态(8.59%~10.77%)≈非晶形结合态(7.56%~13.78%)强交换态(2.53%~5.49%)弱交换态砷(0.18%~0.31%),残渣态砷为主要存在形式;排污口空心莲子草Alternanthera philoxeroides中砷质量分数为854.64mg?kg~(-1),其对水环境中的砷有着较强的富集作用(富集系数≈200);水生植物的生长可对沉积物中砷的迁移转化产生显著影响,水环境中的砷易被富集从而进入食物链中造成潜在的健康风险。因此,在治理水环境砷污染时应考虑砷不同形态之间的转化,从源头上减少砷的排放,降低其对环境所产生的生态风险。     

连续浸提技术测定土壤和沉积物中硒的形态

本文建立了土壤和沉积物中硒的形态分析方法，应用连续化学浸提技术将土壤和沉积物进行连续五次抽提，根据不同形态硒的溶解度，将土壤和沉积中的硒分为可溶态（水溶态）、可交换态及碳酸盐结合态、铁－锰氧化物结合态、有机物－硫化物结合态及元素态、残渣态五种结合形态。种形态硒分级浸提的相对标准偏差均小于４．０％，总回收率（即：五种形态和与总硒的比值）为９３．２－９４．４％。     

小麦根际土壤汞的分布和形态变化

采用根际箱试验和连续化学萃取法,结合氢化物原子吸收光谱法,研究了非根际和根际土壤汞形态分布特征及小麦(Triticum aestivum)生长期土壤汞形态变化.结果表明.非根际汞形态分布顺序为:残渣态>强有机质结合态>碳酸盐铁锰氧化物结合态>腐殖酸络合态>水溶态>交换态,根际汞形态分布为:残渣态>碳酸盐铁锰氧化态>强有机质结合态>交换态>腐殖酸络合态>水溶态.当外源汞进入土壤后,在小麦生长60 d内,植物吸收使残渣态汞和水溶态汞含量明显降低,交换态汞和碳酸盐铁锰氧化态汞含量增加.土壤汞污染程度越大,在小麦中积累的汞就越多.其生物毒性增强,环境危害加大.     

子牙新河下游湿地土壤重金属垂直分布及形态特征

2014年秋季在子牙新河下游湿地采集柱状土壤样品,分析了Cd、Zn、Cu、Pb的垂向分布特征,利用Tessier连续浸提法,分析了典型湿地N1、N3、B3的重金属形态.研究结果表明,Cd、Zn、Cu、Pb含量垂向分布差异性比较大,波动幅度比较大,多数点位Cd、Cu、Zn在11—19 cm深度处出现峰值,可能与过去金属的输入和周期性淹水有关.Zn、Cu、Pb形态分布为残渣态铁锰氧化物结合态有机物结合态可交换态碳酸盐结合态,Cd形态分布为铁锰氧化物结合态可交换态残渣态有机物结合态碳酸盐结合态,Cd的生物有效性较高.湿地淹水条件影响到湿地重金属Cd的交换态和铁锰氧化物结合态的垂直分布.Cd主要以铁锰氧化物结合态的形式存在于湿地土壤中,其百分含量占53.2%,而重金属Zn、Cu、Pb主要以残渣态的形式存在于湿地土壤中,其百分含量均高于60%.根据风险评价编码法(RAC)对重金属的化学形态进行风险评价,风险顺序为:CdZnCuPb,因此重金属Cd应引起足够的重视.     

粤东凤凰山茶区土壤锰、锌赋存形态特征及对茶叶的有效性

采用连续化学提取法对粤东凤凰山茶区12个茶园土壤Mn和Zn的5种赋存形态特征及对茶叶的有效性进行了研究。结果发现,茶区土壤Mn平均含量为337 mg.kg-1,Zn平均含量为166.0 mg.kg-1,Mn和Zn的形态分布规律均表现为残渣态>铁锰氧化物结合态>有机束缚态>可交换态>碳酸盐结合态。土壤铁锰氧化物结合态和碳酸盐结合态Mn含量以及碳酸盐结合态、有机束缚态和铁锰氧化物结合态Zn含量分别与土壤pH值呈显著正相关,可交换态Mn含量与土壤pH值呈显著负相关;有机束缚态Mn、Zn含量以及铁锰氧化物结合态Zn含量分别与土壤有机质含量呈显著正相关,而铁锰氧化物结合态Mn含量与土壤有机质含量呈显著负相关。茶区茶叶Mn平均含量为1 046.3 mg.kg-1,Zn平均含量为42.0 mg.kg-1。茶叶Zn含量分别与土壤可交换态、有机束缚态、碳酸盐结合态Zn含量以及有机质含量呈显著正相关;茶叶Mn含量分别与土壤可交换态、碳酸盐结合态、有机束缚态Mn含量呈显著正相关,而与土壤pH值呈显著负相关。土壤pH值和有机质含量对茶区土壤Mn和Zn的化学形态分布及茶叶中Mn和Zn的累积有重要影响。     

胶州湾不同类型湿地总汞含量与赋存形态的初步研究

为了研究和比较胶州湾贝类养殖区和周边湿地两种不同类型湿地总汞和形态汞分布规律及差异,2013年5月至2014年5月,分别在胶州湾周边湿地(大沽河河口、河套、南弓芦苇地、白沙河)和胶州湾贝类养殖区(红岛、胶南、黄岛、营海)采集了67份沉积物样品,用冷原子吸收法和连续提取法测定其总汞及不同形态汞的含量.研究结果表明,胶州湾周边湿地有机质含量显著高于养殖区沉积物(P0.01),最高值出现在白沙河,为28.72 g·kg~(-1);最低值出现在营海,为1.04 g·kg~(-1),贝类养殖区和周边湿地p H无显著差异性.胶州湾贝类养殖区(0.037—0.228 mg·kg~(-1))和周边湿地(0.027—0.088 mg·kg~(-1))总汞含量无显著性差异.胶州湾贝类养殖区和周边湿地沉积物中不同结合态汞有着相同的分布规律,残渣态汞所占比例最大,交换态和可溶态汞所占比例最小.周边湿地中交换态和可溶态、残渣态汞所占比例大于贝类养殖区.贝类养殖区中碳酸盐结合态、腐殖酸结合态、易氧化有机结合态、难氧化有机结合态汞所占比例均大于周边湿地.研究区域汞污染潜在生态危害程度为:红岛营海黄岛河套白沙河大沽河河口胶南南弓芦苇地,汞的潜在生态风险因子计算结果表明,胶州湾周边湿地以及贝类养殖区沉积物均存在中等以上的生态风险.     

伴随阴离子对土壤Cd形态转化的影响

化学性质各异的伴随阴离子通过影响进入土壤的外源Cd2+后的形态转化,而影响其迁移特性和生物毒性。对此进行了解将有助于采取相应的防治镉污染的技术措施。通过室内连续培养试验(0~70 d),研究了伴随阴离子(NO3-、C1-、SO42-)对Cd2+在土壤中的吸附特性、形态分配与转化特性的影响。结果表明,伴随阴离子对添加外源Cd2+溶液后的土壤Cd吸附作用能力表现为:SO42-NO3-C1-;SO42-处理在20 d时吸附率达最大值(93.61%);NO3-与C1-处理在30 d时吸附率达最大值,分别为82.25%、67.97%。初始状态土壤中Cd主要以残渣态存在,可交换态Cd含量与比例最低,占总Cd含量不到10%。添加1.0 mmol·L-1外源Cd2+处理后,在培养期内(0~70 d),表现为可交换态Cd含量铁锰氧化物结合态Cd含量碳酸盐结合态Cd含量残渣态Cd含量有机结合态Cd含量。土壤可交换态Cd在0~70 d分配系数达到38%~61%,其中SO42-处理培养10 d达到最大值(61.09%),NO3-与C1-处理30 d时达到最大值(分别为43.74%和41.80%)。土壤碳酸盐结合态Cd含量在30 d时趋于饱和,其含量(0~70 d)表现为SO42-C1-NO3-。3种伴随阴离子处理的土壤铁锰氧化物结合态Cd含量在0~50d无显著性差异。有机结合态Cd和残渣态Cd含量随着培养周期延长而逐渐增加,但其吸收转化分配比例相对可交换态、碳酸盐结合态和铁锰氧化物结合态低。从生物利用度系数来评价镉形态的危害程度,初始状态土壤中其危害程度表现为生物潜在可利用态生物难利用态生物易利用态。添加1.0 mmol·L-1的外源Cd2+溶液后,SO42-处理的表现为:生物易利用态生物潜在可利用态生物难利用态;C1-和NO3-处理的表现为生物潜在可利用态生物易利用态生物难利用态。这表明,镉形态在SO42-处理伴随下对土壤造成的危害程度相对C1-和NO3-处理严重。外源Cd2+溶液进入土壤主要转化为可交换态Cd(SO42-NO3-C1-),SO42-处理培养10 d达到最大值(转化系数为61.09%)。可交换态Cd在土壤中具有较强的迁移性,容易被生物吸收利用,对环境影响最大。     

基于粒度的土壤团聚体中砷的形态分布特征

为明确土壤团聚体对砷分布和形态的影响,探讨污染农田中砷的可移动性及其环境风险,采集辽宁省某冶炼厂周边污染与非污染(对照)农田表土,采用湿筛法获得2 mm、2~0.25 mm、0.25~0.053 mm和0.053 mm 4个粒级的团聚体,分析明确了污染与对照土壤团聚体中全砷及污染土壤团聚体中各提取态砷的分布特征。结果表明,污染土壤0.25 mm粒级团聚体含量(78.49%)以及其中砷的分配量(80.83%)均显著高于对照土壤(64.33%、67.8%),其中0.25~0.053 mm粒级团聚体中砷的分配量最高(43.13%)。2 mm、0.25~0.053 mm以及0.053 mm粒级团聚体中各形态砷分布规律一致:残渣态(20.21~99.10 mg·kg~(-1))铁锰氧化物结合态(13.38~26.39 mg·kg~(-1))专性吸附态(5.19~8.86 mg·kg~(-1))非专性吸附态(1.13~2.94mg·kg~(-1))。而2~0.25 mm粒级团聚体中各形态砷为:残渣态(85.91 mg·kg~(-1))专性吸附态(28.48 mg·kg~(-1))铁锰氧化物结合态(25.63 mg·kg~(-1))非专性吸附态(6.00 mg·kg~(-1))。非专性吸附态和专性吸附态砷在0.25 mm粒级团聚体中的含量显著高于0.25 mm粒级团聚体。     

锑矿土壤中As和Sb的分布、形态及生物可利用性

采用微波消解-氢化物发生-原子荧光光谱法测定了晴隆锑矿区土壤中总砷和总锑,利用Tessier连续提取法分析土壤中不同形态砷和锑.结果表明,各采样点土壤As、Sb含量分别为17.98—127.85 mg·kg-1、171.93—601.59 mg·kg-1,远高于贵州省背景值;土壤中砷和锑的存在形态均以残渣态为主,其次是有机结合态、铁锰氧化物结合态和碳酸盐结合态,可交换态很少;土壤中生物可利用态锑占总和0.33%—1.72%,其含量为0.60—3.91 mg·kg-1,而土壤中生物可利用态砷占总和0.09%—0.57%,其含量为0.15—0.48 mg·kg-1.     

Arsenic contamination: a potential hazard to the affected areas of West Bengal, India

Arsenic contamination in groundwater is becoming more and more a worldwide problem. Nearing 50 million of people are at health risk from arsenic contamination at Ganga–Meghna–Bramhaputra basin. The experimental results of the five blocks under Malda district of West Bengal, India, showed that the arsenic concentration in groundwater (0.41–1.01 mg/l) was higher than the permissible limit for drinking water (0.01 mg/l) (WHO) and FAO (Food and Agriculture Organization) permissible limit for irrigation water (0.10 mg/l). The soil arsenic level (13.12 mg/kg) crossed the global average (10.0 mg/kg), but within the maximum acceptable limit for agricultural soil (20.0 mg/kg) recommended by the European Union. The total arsenic concentration on food crops varied from 0.000 to 1.464 mg/kg of dry weight. The highest mean arsenic concentration was found in potato (0.456 mg/kg), followed by rice grain (0.429 mg/kg). The total mean arsenic content (milligrams per kg dry weight) in cereals ranged from 0.121 to 0.429 mg/kg, in pulses and oilseeds ranged from 0.076 to 0.168 mg/kg, in tuber crops ranged from 0.243 to 0.456 mg/kg, in spices ranged from 0.031 to 0.175 mg/kg, in fruits ranged from 0.021 to 0.145 mg/kg and in vegetables ranged from 0.032 to 0.411 mg/kg, respectively. Hence, arsenic accumulation in cereals, pulses, oilseed, vegetables, spices, cole crop and fruits crop might not be safe in future without any sustainable mitigation strategies to avert the potential arsenic toxicity on the human health in the contaminated areas.     

Fractionation and speciation of arsenic in fresh and combusted coal wastes from Yangquan, northern China

In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate.     

Geochemical distribution of trace element concentrations in the vicinity of Boroo gold mine, Selenge Province, Mongolia

The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination.     

宁波市回龙河表层沉积物重金属的形态分析及风险评价

为了解回龙河表层沉积物中重金属的污染状况,采集了表层沉积物样品,测定了重金属Zn、Cu、Pb、Cr、Cd和Ni的总量及其化学形态,并采用潜在生态风险指数法对重金属进行了生态风险评价。结果显示,回龙河表层沉积物中Zn、Cu、Pb、Cr、Cd和Ni均有一定程度的累积,总量分别为286.4～1277.9mg/kg、21.71～146.0mg/kg、10.33～44.20mg/kg、25.13～90.40mg/kg、0.07172～0.3901mg/kg、13.27～157.2mg/kg,其中Cu、Cr、Pb与Ni 4种重金属具有一定的同源特性;形态分析表明,Cu的形态分布以有机结合态为主,最容易迁移释放,Zn、Cr和Ni除残渣态外,铁锰氧化结合态和有机结合态占一定比例,具有潜在风险;潜在生态风险指数法分析表明,沉积物中重金属元素的单一潜在生态风险指数顺序为Cd〉Cu〉Ni〉Zn〉Pb〉Cr,潜在生态危害指数RI均小于150,总体上回龙河处于轻微的生态风险等级。     

Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated biomass: A pilot-scale experience

Pilot-scale combustion is required to treat arsenic-enriched biomass in China. CaO addition to arsenic-enriched biomass reduces arsenic emission. CaO captures arsenic via chemical adsorption to form Ca₃(AsO₄)₂. Large quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China. This process provided a solution to reduce waste volume and disposal cost. Pilot-scale combustion trials were conducted for in site disposal at phytoremediation sites. The reaction mechanism of arsenic capture during pilot-scale combustion should be determined to control the arsenic emission in flue gas. This study investigated three Pteris vittata L. biomass with a disposal capacity of 600 kg/d and different arsenic concentrations from three sites in China. The arsenic concentration in flue gas was greater than that of the national standard in the trial with no emission control, and the arsenic concentration in biomass was 486 mg/kg. CaO addition notably reduced arsenic emission in flue gas, and absorption was efficient when CaO was mixed with biomass at 10% of the total weight. For the trial with 10% CaO addition, arsenic recovery from ash reached 76%, which is an ~8-fold increase compared with the control. Synchrotron radiation analysis confirmed that calcium arsenate is the dominant reaction product.     

广州市蔬菜地土壤重金属污染状况调查及评价

探讨了广州市蔬菜地土壤重金属污染状况,测定了95份土壤样品中铅、镉、铬、砷、汞的含量水平。土壤中铅、镉、铬、砷、汞的含量分别在6.44～153.10mg/kg、0-0.682mg/kg、5.82～101.60mg/kg、0.04～45.36mg/kg、0.01～O.32mg/kg之间。就污染的普遍性而言,铅污染最为普遍,其次是砷污染;就污染的程度而言,镉污染最严重.其次为砷、汞。对比今昔污染变化.广州市土壤污染治理已取得显著成效,但仍需努力。土壤中镉、砷、汞三种元素的变异系数,特别是镉的变异系数较大,这可能预示着点源性污染的存在。     

微波消解-石墨炉原子吸收光谱法测定鸡排泄物中总砷的方法研究（Study on the Determination Method of Total Arsenic in Fowl Dung by Microwave Digestion-Atomic and Graphite Furnace Atomic Absorption Spectrometry）

建立检测鸡排泄物中总砷含量的微波消解-石墨炉原子吸收光谱法.使用硝酸镁和硝酸钯混合溶液作为基体改进剂,在灰化温度1200℃、原子化温度2400℃条件下,采用石墨炉原子吸收光谱法测定鸡排泄物中的总砷含量.结果表明,总砷浓度在0～100ng·mL-1范围内符合郎伯-比尔定律,线性回归方程为Y=0.0013X+0.0098,决定系数0.9976,方法的回收率为98.8%～101.9%,精密度为2.81%,检出限为0.100mg·kg-1.     

广州市菜园土主要蔬菜重金属背景含量的研究

研究了广州市几个主要的蔬菜生产基地种植的白菜、芥蓝、芥菜、菜薹、萝卜、大白菜、豆瓣菜、结球甘蓝、芹菜、菜豆、豌豆、结球莴苣、尖叶莴苣、菠菜、番茄等15种蔬菜中Pb、Hg、Cd、Cr和As等5种重金属的背景质量分数。其背景质量分数为：Pb 0．002～0．148mg/kg；Hg ND-0．006mg/kg；Cd 0．001～0．034mg/kg；Cr 0．002～0．150mg/kg；As 0.001～0．070mg／kg。由于不同种类蔬菜的吸收特性和遗传特性有所不同，其重金属背景质量分数也有很大差异。蔬菜中元素水平还与土壤条件等因素有关。     

Temporal dynamics of arsenic uptake and distribution: food and water risks in the Bengal basin

Abstract

Contaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354?µg/L, with 75% of the sites above the prescribed limit by WHO (10?µg/L) during the boro harvest season. High soil As content (～20.6?mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (～1.75?mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24?µg/L) and behoves strategies, practices to minimize As exposure.     

Geochemical distribution of trace element concentrations in the vicinity of Boroo gold mine,Selenge Province,Mongolia

The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination.