Environmental quality and safety. Supplement最新文献

Golden orfes were examined for uptake, distribution, and elimination of radioactivity administered in the form of a 14C-labelled fluorescent whitening agent (FWA) of the bis(triazolyl)stilbenedisulfonic acid type. Results of these studies are given below. Pilot trials using FWA concentrations of 10 and 100 ppb and a population density of 1 fish per liter show that an equilibrium between uptake and elimination of the FWA develops in the animals within a period of one week; i.e., the incorporated traces of the FWA are not irreversibly bound. The radioactivity is mainly located in the gall bladder and in the intestinal contents, as well as in the liver, throat, and gills. The muscular system (filet) is virtually free from activity. Approximately 1-2% of the FWA amount administered per animal (corresponding to the concentration factors of 7-14) can be temporarily detected in the fish. Radioactivity is eliminated comparatively quickly. Two days following the transfer of the fish into water free from FWA a concentration factor as low as 1 is reached, i.e. from this time the FWA concentration in the animals decreases to less than 10 resp. 100 ppb.

A study was made of the photochemical and biological degradation of two water-soluble fluorescent whitening agents (FWAs): the disodium 4,4'-bis(2-sulfostyryl)-biphenyl (1) and the disodium 4,4-bis ([4-anilino-6-(N-methyl-N-2-hydroxyethyl)amino 1,3,5-triazin-2-yl]amino)stilbene-2,2'-disulfonate (2). Each represents an important class of detergent fluorescent whitening agents. The photochemical degradation of (1) was studied by irradiating diluted aqueous solutions of this compound with a low intensity high pressure mercury vapor lamp. From the intermediate, as well as the ultimate photodegradation products isolated, it can be infered that photodegradation of (1) followed the proposed scheme. The biologica degradation of (1) and (2) by activated sludge under aerobic conditions was studied using equipment similar to that proposed by the OECD for determining the biodegradation of anionic synthetic surface active agents. Under the conditons applied, both FWAs were slowly biodegraded, within 30 days, whereas the photodegradation products of (1) were completely biodegraded within 14 days.

Three components of the dose-response reaction, usually seen as three separate curves, are reviewed as a single continuum of the effect of the dose of any agent upon an organism. The usual considerations of any agent in toxicology are the harmful actions. The individual considerations of an essential nutrient or of a hormone usually suggests a positive action. The third component is the stimulatory action as understood in hormone research and as seen in many studies with minute doses of toxic materials. The coelescence of these concepts into one continuum gives a broad viewpoint which is helpful to understand the biologic implications of any toxic, nutritious or stimulating material under a variety of conditions. Such a view is useful in predicting results and in understanding the reaction of living organisms to their environments; when small amounts of a chemical are added to a biologic system, one parameter may be affected in one way and another parameter in the opposite manner. Consideration of the complete dose-response curve led to the concept of hormology, the sutdy of excitation. The thesis of hormology is that any harmful agent may be stimulatory for any parameter when it is administered in subharmful quantities to an organism existing in a suboptimum environment. Concepts fro hormology allow the suggestion that the zero equivalent point (zep) could be used to replace zero tolerance as a practical, legislative concept for dangerous chemicals in our environment. A reivew of three pharmacology texts revealed four types of dose-response curves. The alpha curve demonstrated a simple toxicity, the beta curve exhibited a single stimulation peak followed by a toxicity as more material was added; the gamma curve showed an initial harmful reaction followed by a stimulatory reaction which, in turn, was followed by a toxic reaction as the quantity of material administered was increased; and the delta curve was essentially a sign wave in which two peaks of stimulation were separated by a "harmful valley", then, as greater concentrations of material were administered, toxicity was noted. A brief review of agents which are stimulatory in minute doses showed that a considerable amount of work had been done with radiation and late work has established emf as a stimulatory vehicle. Little work is done with other physical agents. Organic chemical compounds are known to be stimulatory in small quantities; e.g. dietary antibiotics. The fact that antibiotics stimulate growth in germfree animals and the fact that nongermicides stimulate classic animals proves their direct effect on the animal tissues.