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Tolerable daily intake (TDI) refers to the daily amount of a chemical contaminant that has been assessed safe for human being exposure on long-term basis (usually whole lifetime). [1] TDI specifically occurs to chemicals that humans are exposed to unintentionally or as a contaminant, [ 1 ] where acceptable daily intake refers to chemicals that ...
It is commonly referred to as the main harmful PFAS chemical and PFOA is responsible for many of the negative health effects commonly associated with PFAS. Per- and polyfluoroalkyl substances are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. Different organizations use ...
7 December 2018 The Michigan PFAS Science Advisory Panel releases Scientific Evidence and Recommendations for Managing PFAS Contamination in Michigan, which outlines evidence-based recommendations for the state as well as recommendations for areas of future research or monitoring to address gaps in information. It includes a recommendation that ...
A new EU drinking water directive issued in 2020 adopted PFAS limit values. The limit values are 0.1 μg/L for the sum of 20 PFASs including PFHxS, and 0.5 μg/L for the sum of all PFASs. This directive is binding for all EU member nations. It is a minimum directive, and member states can elect to adopt stricter regulations. [19]
Remediation of per- and polyfluoroalkyl substances refers to the destruction or removal of per- and polyfluoroalkyl substances (PFASs) from the environment. PFASs are a group of synthetic organofluorine compounds, used in diverse products such as non-stick cookware and firefighting foams, that have attracted great concern as persistent organic pollutants.
Threshold limit value − time-weighted average (TLV-TWA): The average exposure on the basis of a 8 hours per day, 40 hours per week work schedule. Threshold limit value − short-term exposure limit (TLV-STEL): A 15-minute TWA exposure that should not be exceeded at any time during a workday, even if the 8-hour TWA is within the TLV-TWA.
For instance, if the ADI is based on data from humans the safety factor is usually 10 instead of 100. The ADI is usually given in mg per kg body weight. [5] The ADI is considered a safe intake level for a healthy adult of normal weight who consumes an average daily amount of the substance in question.
Subsequently, the National Academy of Sciences (NAS) reviewed the health implications of perchlorate, and in 2005 proposed a much higher alternative reference dose of 0.0007 mg/kg/day based primarily on a 2002 study by Greer et al. [6] During that study, 37 adult human subjects were split into four exposure groups exposed to 0.007 (7 subjects ...