Final answer:
The best evidence to support the claim that lead in drinking water will harm humans is the reporting of joint pain after consumption of lead-contaminated water, as this is a known symptom of lead poisoning, which has a significant impact on health, especially in young children. The correct option is a.
Step-by-step explanation:
The claim that lead in drinking water will harm humans can be best supported by the piece of data that states: 'After using water that contains high levels of lead, people started experiencing joint pain.' This statement directly correlates with the known effects of lead poisoning which can cause a range of health issues, including but not limited to joint pain.
Lead exposure is particularly detrimental to younger populations such as children and fetuses, affecting their development. The Flint Michigan Water Crisis is a potent example of the dangers of lead in drinking water, where residents suffered various health problems due to the high lead content in their water supply. It is essential to understand that scientific research has shown even very small amounts of lead, measured in parts per billion (ppb), can cause significant health issues. Symptoms of lead poisoning can include developmental delays, abdominal pain, and neurological changes, and can even be fatal at higher levels.
Given the toxic nature of lead and its ability to leach into drinking water from pipes, especially in areas with older infrastructure, providing evidence of health effects directly experienced by individuals after consuming contaminated water, like joint pain, is critical. This evidence is much more compelling than other options, such as a stained toothbrush, a metallic taste, or leaking pipes, which don't necessarily correlate directly with health outcomes.