Assuming the following is the number of diapers used per day and assuming the number of days in a month is 30.
Newborn – 4 mths **9-10 Diapers/Day
5 mths- 15 mths **7-9 Diapers/Day
16 mths –24 mths **6-7 Diapers/Day
24 mths – 30 mths **5-6 Diapers/Day
A conservative estimate of the total number of diapers used when a child is 2.5 years old is a staggering 9000! Now, I don't know how large an average 'bundle' of used disposable diaper is, but I would think it's a considerable volume. Imagine 9000 non-biodegradable diapers filling the landfill or just as bad, being incinerated contributing to our largest greenhouse with CO2.
If the environmental issue isn't enough to hold sway, here's the cost argument:
Assuming a cost of 19c a diaper, 9000 diapers work out to €1710. And the cost of 30 All-in-One cloth diapers at €16 each? €480.
