In order to evaluate the possible human health risk by phyto-accumulation of five heavy metals, viz. Cr, Cd, Cu, Pb and Ni, four Brassica species, namely B. campestris, B. juncea, B. napus and B. nigra, were grown under field conditions irrigated with 100% (undiluted) and 50% (diluted) wastewater (WW). The groundwater treatment was taken as control. WW irrigations (50% and 100%) were found to increase growth parameters (length, fresh biomass and dry biomass of shoot and root) and seed yield of all Brassica species. Calculated metal indices showed tolerance ability (tolerance index, TolI > 1) of all four Brassica species growing in both 50% and 100% WW-irrigated soil, but none of these could act as hyperaccumulator (bioconcentration factor, BCF < 1, and translocation index, TraI < 100%). Even though WW contained the permissible limit of phyto-elements, the input/addition of them into soil through irrigation caused the accumulation of most of the heavy metals in both leaf and seed parts of all Brassica crops far above the safety limit. Furthermore, the values of hazard quotient (HQ) for single metal (Pb) and total metals in all the crops were greater than 1 (HQ > 1), representing the human health at serious risk.

中文翻译：

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废水灌溉土壤对芸苔属生物中Cr，Cu，Ni，Pb和Cd的生物富集风险分析

为了通过五种重金属的植物积累来评估可能的人类健康风险，即。Cr，Cd，Cu，Pb和Ni这4种芸苔属植物，即B.campestris，B.juncea，B.napus和B.nigra在田间条件下生长，分别用100％（未稀释）和50％（稀释）的废水灌溉（WW）。以地下水处理为对照。发现WW灌溉（50％和100％）可增加所有芸苔属植物的生长参数（茎，根的长度，新鲜生物量和干生物量）和种子产量。计算得出的金属指数显示了所有四个芸苔属的耐受能力（耐受指数，Tol I  > 1）物种在50％和100％的WW灌溉土壤中均生长，但是这些都不能作为超蓄积物（生物富集系数，BCF <1，易位指数，Tra I  <100％）。尽管WW含有植物元素的允许限量，但通过灌溉将其输入/添加到土壤中，导致所有芸苔属作物的叶片和种子部分中大多数重金属的积累远远超过了安全限量。此外，所有作物中单一金属（Pb）和总金属的危险商（HQ）值均大于1（HQ> 1），这表示处于严重危险中的人类健康。