A nurse is performing a home hazard assessment for a client who lives in an older home. The nurse should instruct the client to have the water tested for which of the following elements?

Choice A reason: Magnesium is a naturally occurring mineral in water and is not typically associated with toxicity in household water supplies. While excessive magnesium can cause gastrointestinal upset, it is not considered a primary hazard in older homes. Testing for magnesium is not a standard safety recommendation. Choice B reason: Potassium is also a naturally occurring mineral and is not a common contaminant of concern in household water. Potassium levels in water are generally safe and do not pose a significant health risk. Therefore, routine testing for potassium is unnecessary in the context of home hazard assessments. Choice C reason: Lead is the correct answer because older homes often have plumbing systems that contain lead pipes, solder, or fixtures. Lead can leach into drinking water, especially if the water is acidic or has low mineral content. Chronic exposure to lead causes neurotoxicity, developmental delays in children, hypertension, and kidney damage. Testing for lead is a critical safety measure in older homes to prevent long-term health complications. Choice D reason: Copper can leach into water from plumbing, but copper toxicity is rare and usually requires very high levels. While copper can cause gastrointestinal upset and liver damage in extreme cases, it is not the primary hazard associated with older homes. Lead remains the most significant concern.