National Research Centre for Environmental Toxicity, The University of Queensland, 39 Kessels Rd, Coopers Plains, Brisbane, QLD, 4108, Australia,
Environ Geochem Health. 2013 Dec;35(6):757-66. doi: 10.1007/s10653-013-9527-x. Epub 2013 Jun 1.
Arsenic (As) and lead (Pb) are common contaminants found in mine waste materials. For an evidence-based risk assessment, it is important to better understand the potential interaction of mixed contaminants; and this interaction study was investigated in an in vivo rat model. Following co-administration of a fixed dose of As(V) as in sodium arsenate and different doses of Pb as lead acetate to Sprague-Dawley rats, blood arsenic concentration and bioavailability decreased. A decrease in As blood concentration when lead was co-administered was observed with increasing lead doses. Pharmacokinetic parameters for As in the blood showed faster absorption and elimination of this metalloid in the presence of Pb. The elimination half-life of As decreased from 67 days in As solo group to 27-30 with doses of Pb. Bioavailability of As was also decreased by 30-43 % in the presence of Pb. Decreased urinary excretion of Pb and tissue accumulation were also observed. It indicates lower absorption of As when co-administered with Pb. A probable explanation for these findings is that As co-administration with Pb could have resulted in the formation of less soluble lead arsenate. However, such an interaction between As and Pb could only explain about one-third of the variation when real mine waste materials containing both of these elements were administered to rats. This suggests that other effects from physical and chemical parameters could contribute to the bioavailability of arsenic in complex real environmental samples.
砷（As）和铅（Pb）是矿山废物中常见的污染物。为了进行基于证据的风险评估，了解混合污染物的潜在相互作用非常重要；本研究在体内大鼠模型中研究了这种相互作用。在向 Sprague-Dawley 大鼠共同给予固定剂量的砷酸钠中的 As(V)和不同剂量的醋酸铅后，血液中的砷浓度和生物利用度降低。当共同给予铅时，观察到随着铅剂量的增加，血液中砷的浓度降低。血液中砷的药代动力学参数显示，在 Pb 存在下，这种类金属的吸收和消除更快。As 的消除半衰期从 As 单独组的 67 天减少到 Pb 剂量为 27-30 天。Pb 的存在也使 As 的生物利用度降低了 30-43%。尿铅排泄减少和组织积累也观察到。这表明当与 Pb 共同给予时，As 的吸收减少。这些发现的一个可能解释是，As 与 Pb 共同给予可能导致形成较少可溶性的砷酸铅。然而，当将含有这两种元素的实际矿山废物给予大鼠时，这种 As 和 Pb 之间的相互作用仅能解释约三分之一的变化。这表明物理和化学参数的其他影响可能会影响复杂实际环境样品中砷的生物利用度。
