Below the water table, in the phreatic zone, permeable units that yield groundwater are called aquifers. The ability of the aquifer to store groundwater is dependent on the primary and secondary porosity and permeability of the rock or soil.onsequently, the water table is lower during the summer. This disparity between the level of the winter and summer water table is known as the zone of intermittent saturation, wherein the water table will fluctuate in response to climatic conditions.
The CDC says about 310,000 American kids (1 to 5 years old) have blood-lead levels over 10 micrograms/dL. A U.S. child's main risk of lead poisoning comes from the lead-based house paints in near-universal use before 1950. The paints were banned for housing use in 1978.
Jan. 2, 2008 -- Lead poisoning in infancy may make Alzheimer's disease more likely decades later, a new study shows. Lead poisoning is a well-known danger, especially for young children. Months or years of lead poisoning can stunt children's growth and damage their brain, kidneys, hearing, and mental development.