Can cloud seeding make you sick?

Short answer probably not depends on whats being seeded into the clouds. The subject is open to debate and there are lots of conspiracy theories. As far as I know no person has ever been directly harmed as a result of cloud seeding for weather control.

"silver iodide can cause temporary incapacitation or possible residual injury to humans and mammals with intense or continued but not chronic exposure. However, there have been several detailed ecological studies that showed negligible environmental and health impacts.[14][15][16] The toxicity of silver and silver compounds (from silver iodide) was shown to be of low order in some studies. These findings likely result from the minute amounts of silver generated by cloud seeding, which are 100 times less than industry emissions into the atmosphere in many parts of the world, or individual exposure from tooth fillings.[17] Accumulations in the soil, vegetation, and surface runoff have not been large enough to measure above natural background."-from wikipedia on cloudseeding