Hi all… a new study on lead in drinking water has just been published in the journal Water Research. A total of 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings were analyzed for lead. The authors anticipate that “lead at the tap would not contribute to elevated blood lead levels (BLLs) in young children and adults at the majority of the taps monitored.” However, analysis of the data also revealed that:

  • “Some daycares and elementary schools present system-wide lead release and are likely to cause elevated BLLs in young children
  • Some taps with extreme lead concentrations could cause rare but acute risk of elevated BLL in young children
  • The analysis of a very large dataset of samples in large buildings confirms that lead concentrations at a given tap in a building cannot predict the concentrations at other taps in the same building”

Bill

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Evaluation of exposure to lead from drinking water in large buildings

Elise Deshommes, Robert C. Andrews, Graham Gagnon, Tim McCluskey, Brad McIlwain, Evelyne Dore, Shokoufeh Nour, Michele Prevost

Water Research 99(2016) 46-55  http://dx.doi.org/10.1016/j.watres.2016.04.050

ABSTRACT

“Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings using regulatory and investigative sampling protocols were analyzed to provide lead concentration distributions. Maximum concentrations reached 13,200 and 3890 µg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building. Simulations using the Integrated Uptake Biokinetic (IEUBK) model and lead concentrations after 30 min of stagnation in the dataset showed that, for most buildings, exposure to lead at the tap does not increase children’s blood lead levels (BLLs). However, buildings or taps with extreme concentrations represent a significant health risk to young children attending school or daycare, as the estimated BLL far exceeded the 5 µg/dL threshold. Ingestion of water from specific taps could lead to acute exposure. Finally, for a few taps, the total daily lead intake reached the former World Health Organization (WHO) tolerable level for adults, suggesting potential health risks.”