1. Iron is essential for human body as it is main component of haemoglobin.
2. However, only a small amount is required by human body, and that to in pure form.
3. If it is exposed to human body for a longer period of time and in a large amount, it is obviously hazardous. This is because large amount of iron is not easily absorbed by our body and if iron remain unabsorbed, it may lead to severe issues.