For dry-type transformers having a 220 [degrees] C insulating system and a winding hot-spot temperature of 220 [degrees] C, and with no unusual operating conditions present, the 20-yr life expectancy is a reasonable time frame.he 80 [degrees] C transformer requires operation at 75% or more of full load for a 2-yr payback, and at 100% load to payback in 1 yr over the 150 [degrees] C transformer.
Exposure to arsenic through drinking water is a great threat to human health. Arsenic is a carcinogen and its consumption can negatively affect the gastrointestinal tract and cardiac, vascular and central nervous systems.
A person can come into contact with arsenic in many different ways. Since it is a natural part of the environment, everyone is exposed to small amounts of arsenic. For most people, the largest source of arsenic is in the food we eat. Most foods, including vegetables, fish, and seafood, contain some arsenic. Arsenic in groundwater can enter the body by drinking the water or by eating food cooked in the water. Arsenic does not evaporate into the air and is not easily absorbed through the skin.