Have you ever peed in a swimming pool? If your answer is yes, you are not alone. An average swimming pool contains about 75 liters of urine.
That's what a Canadian scientist discovered. This was investigated by taking 250 water samples from 31 different swimming pools. An examined 25-metre pool contained 830,000 litres, 75 liters of which was urine.
Did you know that urine is also the cause of red eyes after swimming?