Sueitt A P E, Yamada-Ferraz T M, Oliveira A F, Botta C M R, Fadini P S, Nascimento M R L, Faria B M, Mozeto A A
Laboratório de Biogeoquímica Ambiental/ Núcleo de Estudos, Diagnósticos e Intervenções Ambientais, Departamento de Química, Universidade Federal de São Carlos, Caixa Postal 676, Rodovia Washington Luiz, km 235, CEP 13565-905 São Carlos, SP, Brazil.
Laboratório de Biogeoquímica Ambiental/ Núcleo de Estudos, Diagnósticos e Intervenções Ambientais, Departamento de Química, Universidade Federal de São Carlos, Caixa Postal 676, Rodovia Washington Luiz, km 235, CEP 13565-905 São Carlos, SP, Brazil.
Ecotoxicol Environ Saf. 2015 Jul;117:155-63. doi: 10.1016/j.ecoenv.2015.03.034. Epub 2015 Apr 9.
This study aimed to analyze laboratory and field data to assess the ecotoxicological risks of calcium nitrate exposure to freshwater tropical biota. Short-term laboratorial tests resulted in estimated EC₅₀ values of 76.72 (67.32-86.12)mg N-NO₃₋ L(-1) for C. silvestrii and 296.46 (277.16-315.76) mg N-NO₃₋ L(-1) for C. xanthus. Long-term laboratorial tests generated IC₂₅ values of 5.05 (4.35-5.75) and 28.73 (26.30-31.15) mg N-NO₃₋ L(-1) for C. silvestrii and C. xanthus, respectively. The results from in situ mesocosm experiments performed in the Ibirité reservoir (a tropical eutrophic urban water body located in SE Brazil) indicated that C. silvestrii and C. xanthus were not under severe deleterious acute impact due to the treatment because the higher nitrate concentrations determined were 5.2 mg N-NO₃₋ L(-1) (t=24 h; sediment-water interface) and 17.5 mg N-NO₃₋ L(-1) (t=600 h; interstitial water). However, an abrupt decrease in the densities of Cyanophyceae members and other benthic taxa was observed. In summary, the present work contributes greatly to the toxicity data linked to two taxonomically distinct organisms that have never been screened for calcium nitrate sensitivity. Furthermore, considering the problem of the management and restoration of eutrophic environments, our study reports a comprehensive field assessment that allows the elucidation of the possible toxic impacts caused by the addition of calcium nitrate (a remediation technique) on aquatic and benthic organisms as well as the implications on the aquatic ecosystem as a whole, which may greatly allow expanding the current knowledgebase on the topic.
本研究旨在分析实验室和现场数据，以评估硝酸钙暴露对淡水热带生物群的生态毒理学风险。短期实验室测试得出，细鳞斜颌鲴的估计半数有效浓度（EC₅₀）值为76.72（67.32 - 86.12）mg N-NO₃₋ L⁻¹，黄斑褶鮡的为296.46（277.16 - 315.76）mg N-NO₃₋ L⁻¹。长期实验室测试得出，细鳞斜颌鲴和黄斑褶鮡的半数抑制浓度（IC₂₅）值分别为5.05（4.35 - 5.75）和28.73（26.30 - 31.15）mg N-NO₃₋ L⁻¹。在伊比里特水库（位于巴西东南部的一个热带富营养化城市水体）进行的原位中宇宙实验结果表明，由于处理过程中测定的较高硝酸盐浓度分别为5.2 mg N-NO₃₋ L⁻¹（t = 24小时；沉积物 - 水界面）和17.5 mg N-NO₃₋ L⁻¹（t = 600小时；间隙水），细鳞斜颌鲴和黄斑褶鮡并未受到严重的有害急性影响。然而，观察到蓝藻门成员和其他底栖类群的密度急剧下降。总之，本研究极大地丰富了与两种分类学上不同的生物相关的毒性数据，这两种生物此前从未进行过硝酸钙敏感性筛查。此外，考虑到富营养化环境的管理和恢复问题，我们的研究报告了一项全面的现场评估，该评估能够阐明添加硝酸钙（一种修复技术）对水生和底栖生物可能产生的毒性影响以及对整个水生生态系统的影响，这可能极大地扩展当前关于该主题的知识库。
