What was the most common lead source of contamination in drinking water in the past?

The most common lead source of contamination in drinking water historically came from the use of lead solder, particularly in plumbing systems. Among the options listed, the one that is most closely associated with lead contamination in water supply systems is the solder that typically contains 95% tin and 5% antimony.

Using lead in plumbing contractors was a common practice for many years. Lead-based solders were often used to join pipes, especially in older infrastructures. As these solders corroded, lead leached into the water supply, leading to potential health hazards for consumers. Although antimony is present in the solder composition, which provides some beneficial qualities to the alloy, the key component here is that this solder also contained a percentage of lead, a substance known for its toxicity and ability to contaminate drinking water over time.

This historical context clarifies why this specific composition is relevant when discussing lead sources in drinking water contamination, distinguishing it from other options that are not typically associated with lead.