ABSTRACT
Filtration, disinfection, and circulation of aquarium water often proves inadequate to maintain an environment such that these animals do not develop mycotic or bacterial infections. Attempts have been made to further purify the water in such a closed system by employing ultraviolet irradiation of the water on the effluent side of the filter system, but because of the large volume of water involved and the relative inefficiency of ultraviolet (UV) radiation, the system was found to have little value in reducing bacterial counts in the various tanks. Numerous studies have documented the effects of DDT type organochlorine insecticides on the immune system. The effects of polychlorinated biphenyl (PCB) compounds on the immune system are much more striking than DDT causes, and have been noted in various species including man. Not only is there atrophy of lymphoid tissue and decreased immunoglobulin levels, but in both experimental animals and accidentally exposed humans, there is increased susceptibility to viral, bacterial, and mycotic infections.
