Daily Archives: March 18, 2015

335 Pharmaceutically Active Compounds (PhACs) in Canada Drinking Water Pose Negligible Risk

Khan U, Nicell J. Human Health Relevance of Pharmaceutically Active Compounds in Drinking Water. AAPS J. 2015 Mar 5. 

In Canada, as many as 20 pharmaceutically active compounds (PhACs) have been detected in samples of treated drinking water. The presence of these PhACs in drinking water raises important questions as to the human health risk posed by their potential appearance in drinking water supplies and the extent to which they indicate that other PhACs are present but have not been detected using current analytical methods. Therefore, the goal of the current investigation was to conduct a screening-level assessment of the human health risks posed by the aquatic release of an evaluation set of 335 selected PhACs. Predicted and measured concentrations were used to estimate the exposure of Canadians to each PhAC in the evaluation set. Risk evaluations based on measurements could only be performed for 17 PhACs and, of these, all were found to pose a negligible risk to human health when considered individually. The same approach to risk evaluation, but based on predicted rather than measured environmental concentrations, suggested that 322 PhACs of the evaluation set, when considered individually, are expected to pose a negligible risk to human health due to their potential presence in drinking waters. However, the following 14 PhACs should be prioritized for further study: triiodothyronine, thyroxine, ramipril and its metabolite ramiprilat, candesartan, lisinopril, atorvastatin, lorazepam, fentanyl, atenolol, metformin, enalaprilat, morphine, and irbesartan. Finally, the currently available monitoring data for PhACs in Canadian surface and drinking waters was found to be lacking, irrespective of whether their suitability was assessed based on risk posed, predicted exposure concentrations, or potency.

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Century-Long Variations in Climate Connected to Solar Activity

M. Ogurtsov, M. Lindholm, R. Jalkanen, S. Veretenenko. Evidence for the Gleissberg solar cycle at the high-latitudes of the Northern Hemisphere. Advances in Space Research 55 (2015) 1285–1290.

Time evolution of growing season temperatures in the Northern Hemisphere was analyzed using both wavelet and Fourier approaches. A century-scale (60–140 year) cyclicity was found in the summer temperature reconstruction from the Taymir peninsula (∼72° N, ∼105° E) and other high-latitude (60–70° N) regions during the time interval AD 1576–1970. This periodicity is significant and consists of two oscillation modes, 60–70 year and 120–140 year variations. In the summer temperatures from the Yamal peninsula (∼70° N, ∼67° E) only a shorter-term (60–70 year) variation is present. A comparison of the secular variation in the Northern Hemisphere temperature proxies with the corresponding variations in sunspot numbers and the fluxes of cosmogenic 10Be in Greenland ice shows that a probable cause of this variability is the modulation of temperature by the century-scale solar cycle of Gleissberg. This is consistent with the results obtained previously for Northern Fennoscandia (67°–70° N, 19°–33° E). Thus, evidence for a connection between century-long variations in solar activity and climate was obtained for the entire boreal zone of the Northern Hemisphere.

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Phthalates in China Drinking Water

Liu X, Shi J, Bo T, Li H, Crittenden JC. Occurrence and risk assessment of selected phthalates in drinking water from waterworks in China. Environmental Science and Pollution Research International 2015 Mar 11.

The first nationwide survey of six phthalates (diethyl phthalate (DEP); dimethyl phthalate (DMP); di-n-butyl phthalate (DBP); butyl benzyl phthalate (BBP); bis(2-ethylhexyl) phthalate (DEHP); din-octyl phthalate (DnOP)) in drinking waters from waterworks was conducted across seven geographical zones in China. Of the six target phthalates, DBP and DEHP were the highest abundant phthalates with median (± interquartile range) values of 0.18 ± 0.47 and 0.18 ± 0.97 μg/L, respectively, but did not exceed the limit values in China’s Standards for Drinking Water Quality. These phthalates in drinking water were generally higher in the northern regions of China than those in the southern and eastern regions. Based on the investigated concentrations, lifetime exposure risk assessment indicated that phthalates in drinking water did not pose carcinogenic and noncarcinogenic risks to Chinese residents, even under the conservative scenario (with 95th percentile risk). In addition, we found that DEHP contributed the greatest risk to the total exposure risk of all the selected phthalates and oral ingestion was the main exposure route for phthalates in drinking water.

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