History
In "Ancient Egyptian Culture Revealed," Moustafa Gadalla describes the ancient Egyptians' fishing method, complete with lead weights on their nets.
Easy to Use
Image by Flickr.com, courtesy of tox brown
Lead is simple to use. According to the Periodic Table, it has a low melting point of 327.5 degrees Celsius, which can be achieved on a campfire or kitchen stove.
Density
Lead, with a density of 11.34 g/cm3, is much heavier than water and sinks quickly. According to a University of Oregon website, density is the weight of a cubic centimeter of any material.
Cost and Availability
Another factor in the usage of lead is its low cost and easy availability. Lead can be purchased as a raw material or old lead can be melted down and reused.
Health Issues
According to the University of Medicine & Dentistry of New Jersey, lead is a highly toxic substance that builds up in a person's body, causing health problems or even death.
Environment Issues
Image by Flickr.com, courtesy of Logan Ingalls
The use of lead sinkers endangers waterbirds, according to New Hampshire Fish and Game Department.