Which chemical agents that manifest most of their symptoms for several hours to days?

Chemical agents such as nerve agents (e.g., sarin, VX) and certain persistent organic pollutants (e.g., organophosphates) can manifest symptoms several hours to days after exposure. These agents often disrupt neurological functions, leading to delayed symptoms like respiratory distress and convulsions. Additionally, some heavy metals (e.g., lead, Mercury) can cause long-term health effects that may take time to manifest. The delayed onset of symptoms can complicate diagnosis and treatment.