Ecotoxicological evaluation of wastewater treatment plant effluent discharges: a case study in Prato (Tuscany, Italy).

Textile wastewaters, which contain numerous chemicals such as dyes, surfactants, solvents, organic and inorganic salts, can cause severe pollution problems for the receiving freshwaters. The ecotoxicity of wastewaters in Prato, where there are about 14,000 textile and related factories, was investigated from 1996-1999 by means of bioassays. 147 samples of reclaimed wastewater were collected at the outlets of 4 centralized wastewater treatment plants. The acute and chronic toxicity of the effluents was measured with bioassays using three different target organisms: green algae (Pseudokirchneriella subcapitata), crustaceans (Daphnia magna) and bioluminescent bacteria (Vibrio fischeri). Toxicity was expressed as Effective Concentration 50 (EC50) and Toxic Units (TU). The results indicated that the effluents did not have significant acute toxicity: only 2.74% (EC50<100%, TU>1) of the 146 samples tested with crustaceans and 6.52% (EC50<50%, TU>2) of the 78 tested with bioluminescent bacteria showed toxic effects. With algae, slight chronic toxicity was found in 49.33% (mean EC50 value=86.56%, mean TU=1.16) of the 140 samples tested. The highest relative response was found with the algal assay using Pseudokirchneriella subcapitata: 49.33% of 140 samples showed chronic toxicity at 96 hours (EC50<100%).

[Isolation frequency of enteropathogenic Escherichia coli in the Patro distric from 1974 to 1986]. / Frequenza di isolamento di Escherichia coli enteropatogeni nel comprensorio pratese, dal 1974 al 1986.

In the Prato district in the years 1974-1986 the isolation frequency of serogropus of enteropathogenic Escherichia coli on 12,251 faeces samples pertinent to infantile diarrhoea has been studied. The research reveals a constant decrease in the isolation frequency of the serogroups considered. An hypothesis is quite difficult but this finding is taking world-wide consistency: furthermore some items are distinctive of the researched district and therefore quite interesting.

[Evaluation of interferences in electronic platelet count]. / Valutazione di interferenze nel conteggio elettronico delle piastrine.

A platelets count was performed on 100 subjects using both the electronic counter and a manual method; the results obtained concerning healthy subjects are overlapping. In subjects with structural alterations regarding platelets and red blood cells, the electronic counter method has overestimated the number, yet making note of it.

[Squalene-cholesterol ratio in the amniotic fluid and gestational age: changes in the threshold in relation to the preparation of the sample]. / Rapporto squalene/colesterolo nel liquido amniotico ed epoca gestazionale: variazione della soglia in relazione alla preparazione del campione.

The squalene/cholesterol ratio in pellets prepared from amniotic fluid is closely correlated to the gestation age and shows a marked increase in the 39th week of pregnancy. However, the absolute value of the squalene/cholesterol ratio may very considerably in relation to the process used to prepare the sample. The washing of the sedimentary cells seems to be critical point in this procedure; therefore, if it is not correctly standardized, erroneous result may be obtained.

[Evaluation of an automatic system for the electrophoretic fracturing of serum proteins and a comparison with the manual method]. / Valutazione di un sistema automatico per il frazionamento elettroforetico delle sieroproteine e confronto con il metodo manuale.

A few weeks ago, the automatized apparatus known as Hite System 600 for the electrophoretic separation of serum proteins was put into use for the first time in our laboratory. In order to evaluate the two methods, the automatized one and the previously used manual one, we conducted a series of quality checks concerning both accuracy and precision. In addition, the correlation between the two methods was studied. Our results demonstrated that the automatized method was more precise even though the two methods showed a perfect overlap.