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Naegleria fowleri is a protozoan found naturally in hot springs and warm surface waters. It can cause usually lethal primary amoebic meningoencephalitis. The goal of this study was to determine the occurrence of N. fowleri in drinking water supply wells in Arizona. Nested polymerase chain reaction was used to detect trophozoites and cysts, but not to assess viability. A total of 185 samples were collected from 113 wells before disinfection. The presence of N. fowleri deoxyribonucleic acid was confirmed in 10.6% of wells. No correlations were found between the presence of N. fowleri and heterotrophic bacteria, coliforms, Escherichia coli, temperature, specific conductance, or turbidity. N. fowleri was detected in 10.0% of initial and 17.2% of purged well samples, suggesting that N. fowleri may be present in the aquifer or detach from the well casing or pump column during pumping.

With their increasing use, nanoparticles will become concentrated in urban effluents in the future. Both adequate monitoring methods and water treatment technologies will be necessary to assess and avoid consumer exposure. This paper reports results in these two challenging areas for both organic and inorganic nanoparticles. Treatment experiments indicate that lamellar settling is better adapted than dissolved air flotation for SiO(2) nanoparticles removal. The use of 120 mg/L of Aqualenc coagulant without flocculant addition allows 99% removal to be achieved for an initial concentration of 1 g/L. On the other hand, the dissolved air flotation process implemented under the usual industrial conditions does not permit removal of SiO(2) nanoparticles. In this case SiO(2) removal occurs only by settling in the flocculator tank. Application of a high resolution liquid chromatography/mass spectrometry (LC/MS) technique to a small selection of treated urban effluents indicates that C(60) fullerenes are not yet widely distributed in effluents; however non-point sources cannot be entirely ruled out.