Most male fin and blue whales sing at around 17 to 18 hertz, which is too deep for humans to hear, but the 'lonely' whale communicates at 52 hertz. When more recordings were released in the nineties, Dr Watkins studied the 52 hertz whale more closely.
The average person needs to absorb just a small amount of iron each day to stay healthy (around 1 mg for adult males and 1.5 mg for menstruating females). To achieve this, however, we need to consume several times that amount. This is because our bodies absorb only a fraction of the iron contained in the foods we eat.
Recommended Intake. Men and women over 50 need at least 8 milligrams of iron per day, while women 50 and under need at least 18 milligrams of iron per day. You shouldn't consume more than 45 milligrams of iron per day from supplements or food, as this could cause toxicity symptoms.