The results show that except for the oxy- TC all other target analytes were detected in the antibiotic plant effluent. TC is the most frequently detected antibiotic in the samples. It was detected in five (of eight) waste water samples, with the maximum concentration of 0.412 μg/l. Doxycycline was detected in two (with a maximum of 0.439 μg/l), and chlor-TC was found in only one waste water sample (0.459 μg/l). TC has been detected widely in European and North American rivers. Median and maximum levels of TC of 0.16 and 1.9 μg/l, respectively, were reported in American streams [10 , 11], which was comparable to the level in the NDF wastewater effluent. TC also was detected at 0.03 to 0.085 μg/l and a maximum concentration of 0.48 μg/l in German rivers [12 , 13].
Chlor-TC were reported 20 ng/l in river waters in Switzerland [18], which was about 1: 2.5 in magnitude of the NDF industrial effluent (0.358 μg/l) in the present study. The same can be said about receiving waters, with the difference that several mechanisms tend to decrease these concentrations (e.g. biodegradation, sorption, photo degradation). Although these levels may not pose direct risks to human health via contaminated drinking water nevertheless, the continuous introduction of these chemicals in the environment makes them “persistent, “regardless of their environmental half -life. Some TAs may reach drinking water supplies at trace levels, and some of these chemicals may survive drinking water treatment to be introduced in potable water distribution systems. In addition, the effects of this exposure through drinking water consumption are far from being understood, and the fact that these chemicals are not present alone
makes it even harder
The results show that except for the oxy- TC all other target analytes were detected in the antibiotic plant effluent. TC is the most frequently detected antibiotic in the samples. It was detected in five (of eight) waste water samples, with the maximum concentration of 0.412 μg/l. Doxycycline was detected in two (with a maximum of 0.439 μg/l), and chlor-TC was found in only one waste water sample (0.459 μg/l). TC has been detected widely in European and North American rivers. Median and maximum levels of TC of 0.16 and 1.9 μg/l, respectively, were reported in American streams [10 , 11], which was comparable to the level in the NDF wastewater effluent. TC also was detected at 0.03 to 0.085 μg/l and a maximum concentration of 0.48 μg/l in German rivers [12 , 13].Chlor-TC were reported 20 ng/l in river waters in Switzerland [18], which was about 1: 2.5 in magnitude of the NDF industrial effluent (0.358 μg/l) in the present study. The same can be said about receiving waters, with the difference that several mechanisms tend to decrease these concentrations (e.g. biodegradation, sorption, photo degradation). Although these levels may not pose direct risks to human health via contaminated drinking water nevertheless, the continuous introduction of these chemicals in the environment makes them “persistent, “regardless of their environmental half -life. Some TAs may reach drinking water supplies at trace levels, and some of these chemicals may survive drinking water treatment to be introduced in potable water distribution systems. In addition, the effects of this exposure through drinking water consumption are far from being understood, and the fact that these chemicals are not present alonemakes it even harder
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