Moreover, even sequestrants that do not form strong complexes with lead may increase lead release. In a recent model distribution system study, for instance, an abrupt increase in the dose of sodium silicate was followed by elevated iron release from corroded cast iron pipe sections and lead release from lead pipes downstream. In the long term, silicate treatment may decrease iron release even if it initially does the opposite, but anticipating the short-term implications highlighted here will help protect water quality. Testing that does not account for interactions between lead and iron, then, may underestimate the true risk of elevated lead associated with sequestration.