The above might be a good option for removing microbial pathogens in surface or rainwater. But it is necessary to ensure that the treated water does not have health hazardous amounts of contaminants like BPA or Pthalates sodis.ch/index_EN The above might be a good option for removing microbial pathogens in surface or rainwater. But it is necessary to ensure that the treated water does not have health hazardous amounts of contaminants like BPA or Pthalates sodis.ch/.../news_documents/deha_dehp_indien.pdf. Antimony Antimony speeds up chemical processes in the manufacture of PET (catalyst). However, antimony does not get into the water unless the bottles are stored for a very long time or heated to very high temperatures. The storage times and temperatures in question far exceed those that are involved in the correct application of the SODIS method. There is therefore no danger to the health of SODIS users. Adipates and phthalates Adipates and phthalates are used as softeners in the production of certain types of plastics and packaging materials (e.g. PVC). Adding these substances to the plastic makes it more flexible and easier to work. Although these softeners are not particularly toxic, they do represent a threat to health if they are consumed in large quantities. However, softeners are not needed in the production of PET. If softeners are found in the water from PET bottles, they must have been in the water before the bottles were filled Aldehydes Aldehydes are formed when the plastic is heated in the manufacturing process for PET bottles. A research group in Eawag, the Swiss Federal Institute of Aquatic Science and Technology,, therefore researched the questions of whether formaldehydes and acetaldehydes are transferred from the PET bottles to the water when the SODIS method is applied, and if so, in what quantities. It was found that exposure to the sun has no effect on the concentration of acetaldehydes, though the concentration of formaldehydes does increase with the length of exposure. However the concentrations of aliphatic aldehydes remained far below the state regulatory limit for drinking water in all samples. Therefore, the SODIS method does not pose a health risk. - sodis.ch/methode/forschung/pet/index_EN The efficacy of simulated solar disinfection (SODIS) against coxsackievirus, poliovirus and hepatitis A virus. Abstract The antimicrobial activity of simulated solar disinfection (SODIS) against enteric waterborne viruses including coxsackievirus-B5, poliovirus-2 and hepatitis A virus was investigated in this study. Assays were conducted in transparent 12-well polystyrene microtitre plates containing the appropriate viral test suspension. Plates were exposed to simulated sunlight at an optical irradiance of 550 Wm(-2) (watts per square metre) delivered from a SUNTEST™ CPS+ solar simulator for 6 hours. Aliquots of the viral test suspensions were taken at set time points and the level of inactivation of the viruses was determined by either culture on a HeLa cell monolayer for coxsackievirus-B5 and poliovirus-2 or by utilising a chromogenic antibody-based approach for hepatitis A virus. With coxsackievirus-B5, poliovirus-2 and hepatitis A virus, exposure to SODIS at an optical irradiance of 550 Wm(-2) for 1-2 hours resulted in complete inactivation of each virus. The findings from this study suggest that under appropriate conditions SODIS may be an effective technique for the inactivation of enteric viruses in drinking water. However, further verification studies need to be performed using natural sunlight in the region where the SODIS technology is to be employed to validate our results. ncbi.nlm.nih.gov/pubmed/23165710
Posted on: Thu, 04 Dec 2014 00:57:13 +0000