Because those who exprience health symptoms after spraying still report the symptoms. Also, if you lick around your lips after spending a lot of time outside on a heavy spray day, your skin will have a metalic taste as will any herbs you have growing if you pick and eat them without washing, fresh after a spray induced rain. I wish these stories of the spray now being made of remedies for humans and the polluted environment were true. The evidence remains for toxic spraying. It's pure rumor right now. I do have faith it will stop one day. Blocking the sun is a bad idea no matter with what.