Biotic ligand model development for Zn and Pb in estuarine and marine waters: interactive influences of salinity and dissolved organic carbon

金属开采和冶炼在加拿大经济中发挥着关键作用(占全国GDP的3.2%，创造了36.8万个就业机会)。加拿大是铅和锌的主要生产国，其中大部分用于出口。这两种金属可能对水环境有害，监管压力，特别是在欧洲和美国，正威胁着这些市场。目前的监管准则往往依赖于预防原则(PP)，而不是健全的科学，并倾向于一刀切的方法；迫切需要基于科学的监管工具，这些工具可以在特定地点的基础上应用，以避免任意应用PP。目前的监管重点是海洋和河口环境。我们的团队由一名水生毒物学家、一名环境化学家和一名在海洋DOC(溶解有机碳)收集方面具有特定专业知识的外国合作者(巴西)组成。由于我们帮助开发了生物配体模型(BLM)，该模型已被证明在淡水环境中对抗PP的应用非常有效，我们的团队已被两个行业支持的金属研究组织(国际铅锌研究组织，ILZRO和国际锌协会，IZA)招募，以生成用于开发海洋/河口铅和锌的BLM的数据。这项研究将集中在对金属最敏感的生物、贻贝、海胆和牡蛎的早期生命阶段(48-72小时发育试验)，并将检查两个主要水质变量盐度和DOC的交互影响。将对关键组织残留物方法进行评估。两名理科硕士研究项目将集中在(I)铅和锌对贻贝胚胎的毒性背后的生理机制，以及(Ii)海洋生物的化学特征及其与金属的相互作用，来访的巴西研究生将为现场验证练习做出贡献。最终的产品将是基于科学的新模型，这些模型可以作为风险评估和监管工具，由政府和行业在全球范围内使用。

Metal mining and smelting plays a key role in the Canadian economy (3.2% of the national GDP, 368,000 jobs). Canada is a major producer of both lead and zinc, the majority of which is sold for export. Both metals may be hazardous to the aquatic environment, and regulatory pressures, particularly in Europe and the U.S.A., are threatening these markets. The current regulatory guidelines often rely on the Precautionary Principle (PP) rather than sound science, and favour a blanket approach; there is a critical need for science-based regulatory tools that can be applied on a site-specific basis so as to avoid arbitrary application of the PP. Regulatory focus at present is on the marine and estuarine environment. Our team consists of an aquatic toxicologist, an environmental chemist, and a foreign collaborator (Brazil) with specific expertise in the collection of marine DOC (dissolved organic carbon). As we helped to develop the Biotic Ligand Model (BLM), which has proven to be very effective in countering application of the PP in freshwater environments, our team has been recruited by two industry-supported metal research organizations (International Lead Zinc Research Organization, ILZRO, & International Zinc Association, IZA) to generate data for development of marine/estuarine BLMs for Pb & Zn,. The research will focus on the organisms which are most sensitive to metals, the early life stages of mussels, sea urchins, and oysters (48-72h development tests), and will examine the interactive influences of two major water quality variables, salinity and DOC. A critical tissue residue approach will be evaluated. Two M.Sc. research projects will focus on (i) the physiological mechanisms behind Pb and Zn toxicity to mussel embryos and (ii) chemical characterization of marine DOCs and their interactions with metals, and visiting Brazilian graduate students will contribute to a field validation exercise. The ultimate products will be new science-based models that can be used as risk assessment and regulatory tools by by government and industry on a worldwide basis.