Investigating elevated copper and lead levels in school drinking water

Abstract

Copper and lead continue to be detected at levels above drinking water guidelines in Canadian schools. Although water is typically not an important source of these metals, intermittent use and corrosive water can cause copper and lead to leach from plumbing. Exposure to elevated copper levels is linked to acute gastrointestinal effects in the short term and possible liver effects in the long term, whereas even low level lead exposures are associated with neurodevelopmental effects. Because school water is not regularly monitored for corrosion metals, elevated concentrations are often brought to the attention of public health officials through unexpected circumstances. Here, the death of salmon eggs in a classroom aquarium triggered an investigation that found elevated levels of copper and lead in the school's drinking water. The investigation was then expanded to the school district. Copper and lead levels varied considerably across schools as well as in outlets located in the same school. The effectiveness of flushing, which was implemented as a mitigation strategy, was also found to differ by school building and outlet. Actions described in this case report may be informative for health authorities across Canada.