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.
Children may show signs of toxicity with ingestions of 10-20 mg/kg of elemental iron. Serious toxicity is likely with ingestions of more than 60 mg/kg. Iron exerts both local and systemic effects and is corrosive to the gastrointestinal mucosa and can affect the heart, lungs, and liver. Excess free iron is a mitochondrial toxin that leads to derangements in energy metabolism.