Seeding Operations & Atmospheric Research
Glaciogenic Cloud Seeding
Since the discovery of glaciogenic materials more than 40 years ago, silver iodide has been the most widely used cloud seeding material. Silver iodide enhances the ice crystal concentration in clouds by either nucleating new crystals or freezing cloud droplets.
Sliver Toxicity: https://www.nature.nps.gov/hazardssafety/toxic/silver.pdf
“Hazards to fish, wildlife, and other non-human biota:
In fish and amphibian toxicity tests with 22 metals and metalloids, silver was the most toxic tested element as judged by acute LC50 values. In solution, ionic silver is extremely toxic to aquatic plants and animals. Among all tested species, the most sensitive individuals to silver were the poorly nourished and young and those exposed to low water hardness or salinity.”
Is Cloud seeding Harmful?
The Office of Environment, Health and Safety, UC Berkeley, rates silver iodide as a Class C, non-soluble, inorganic, hazardous chemical that pollutes water and soil.(8) It has been found to be highly toxic to fish, livestock and humans.(6,7,8,9) Numerous medical articles demonstrate that humans absorb silver iodide through the lungs, nose, skin, and GI tract.(7,8,9) Mild toxicity can cause GI irritation, renal and pulmonary lesions, and mild argyria (blue or black discoloration of the skin). Severe toxicity can result in hemorrhagic gastroenteritis, shock, enlarged heart, severe argyria, and death by respiratory depression.(8)
Moreover, a key manufacturer of silver iodide for weather modification, Deepwater Chemicals, warns of potential health effects of silver iodide in their Material Safety Data Sheet as follows:
Chronic Exposure/Target Organs: Chronic ingestion of iodides may produce “iodism”, which may be manifested by skin rash, running nose, headache and irritation of the mucous membranes. Weakness, anemia, loss of weight and general depression may also occur. Chronic inhalation or ingestion may cause argyria characterized by blue-gray discoloration of the eyes, skin and mucous membranes. Chronic skin contact may cause permanent discoloration of the skin.(10)
Under the guidelines of the Clean Water Act by the EPA, silver iodide is considered a hazardous substance, a priority pollutant, and as a toxic pollutant.(10)