Why we have to use lead free solder?

ANSWER:The use of lead has been reduced over the years because exposure to lead can cause health and reproductive problems. The reason is lead is a heavy metal and once introduced into your body, it is almost impossible to remove it again. Lead has been removed from most paints produced in the US, although some foreign countries do not feel this is in their best interests to use lead free paints and products to the detriment of their citizens. The US has also removed lead from the gasoline we use. See the related link for more information on lead poisioning.