tailieunhanh - Mercury Hazards to Living Organisms - Chapter 8

Chương này tổng hợp tài liệu có sẵn trên các sát thương của các hợp chất thủy ngân vô cơ và hữu cơ sinh vật nước ngọt và biển, ảnh hưởng của lộ trình quản lý mercurials khác nhau về sự tồn tại của đại diện của các loài chim nước, passerines, chim ăn thịt, và các nhóm gia cầm khác, và gây chết các các hợp chất organomercury đối với con người, động vật có vú phòng thí nghiệm nhỏ, vật nuôi, mèo và chó trong nước, và các loài khác nhau của động vật hoang dã. Cái chết. | Part 3 Lethal and Sublethal Effects of Mercury under Controlled Conditions 2006 by Taylor Francis Group LLC Chapter 8 Lethal Effects of Mercury This chapter synthesizes available literature on the lethality of inorganic and organic mercury compounds to freshwater and marine biota the effect of route of administration of various mercurials on the survival of representative species of waterfowl passerines raptors and other avian groups and the lethality of organomercury compounds to humans small laboratory mammals livestock domestic cats and dogs and various species of wildlife. Death is the only biological variable now measured that is considered irreversible by all investigators. Nevertheless time of death is modified by a host of physical chemical biological metabolic and behavioral variables and it is unfortunate that some regulatory agencies still set mercury criteria to protect natural resources and human health on the basis of death usually concentrations producing mortality and some variable uncertainty factor. Mercury criteria for protection of natural resources and human health as discussed in Chapter 12 should be based at a minimum on the highest dose tested or highest tissue concentration found that does not produce death impaired reproduction inhibited growth or disrupted well-being. aquatic organisms Lethal concentrations of mercury salts ranged from less than pg Hg L to more than pg L for representative sensitive species of marine and freshwater organisms Table . The lower concentrations of less than pg L recorded were usually associated with early developmental stages long exposures and flowthrough tests Table . Among teleosts females and larger fish were more resistant to lethal effects of mercury than were males and smaller fishes Diamond et al. 1989 . Among metals tested mercury was the most toxic to aquatic organisms and organomercury compounds showed the greatest biocidal potential Eisler 1981 Jayaprakash and .