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.
How much iron do I need? The amount of iron you need is: 8.7mg a day for men over 18; 14.8mg a day for women aged 19-50 years; 8.7mg a day for women over 50; You should be able to get all the iron you need from your daily diet. Women who lose a lot of blood during their monthly period (heavy periods) are at higher risk of iron deficiency anaemia and may need to take iron supplements.