Lead (Pb) quantification in potable water samples: implications for regulatory compliance and assessment of human exposure

Environ Monit Assess. 2013 Feb;185(2):1355-65. doi: 10.1007/s10661-012-2637-6. Epub 2012 May 4.

Abstract

Assessing the health risk from lead (Pb) in potable water requires accurate quantification of the Pb concentration. Under worst-case scenarios of highly contaminated water samples, representative of public health concerns, up to 71-98 % of the total Pb was not quantified if water samples were not mixed thoroughly after standard preservation (i.e., addition of 0.15 % (v/v) HNO(3)). Thorough mixing after standard preservation improved recovery in all samples, but 35-81 % of the total Pb was still un-quantified in some samples. Transfer of samples from one bottle to another also created high errors (40-100 % of the total Pb was un-quantified in transferred samples). Although the United States Environmental Protection Agency's standard protocol avoids most of these errors, certain methods considered EPA-equivalent allow these errors for regulatory compliance sampling. Moreover, routine monitoring for assessment of human Pb exposure in the USA has no standardized protocols for water sample handling and pre-treatment. Overall, while there is no reason to believe that sample handling and pre-treatment dramatically skew regulatory compliance with the US Pb action level, slight variations from one approved protocol to another may cause Pb-in-water health risks to be significantly underestimated, especially for unusual situations of "worst case" individual exposure to highly contaminated water.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Drinking Water / chemistry*
  • Environmental Exposure / analysis
  • Environmental Exposure / statistics & numerical data*
  • Environmental Monitoring
  • Environmental Policy
  • Guideline Adherence
  • Humans
  • Lead / analysis*
  • Public Health
  • United States
  • United States Environmental Protection Agency
  • Water Pollutants, Chemical / analysis*
  • Water Pollution / legislation & jurisprudence
  • Water Pollution / statistics & numerical data*

Substances

  • Drinking Water
  • Water Pollutants, Chemical
  • Lead