What signs may indicate pesticide poisoning in humans?

Severe headaches, dizziness, and nausea are primary signs of pesticide poisoning in humans. These symptoms can arise soon after exposure to harmful chemicals, indicating that the body is reacting negatively to the pesticide. Headaches may result from the impact of toxic substances on the nervous system, while dizziness and nausea can occur due to various mechanisms, including interference with normal brain function or gastrointestinal distress. Recognizing these symptoms is crucial for timely medical intervention, as pesticide poisoning can lead to serious health complications.

The other options describe symptoms that are not associated with pesticide poisoning. Increased appetite and weight gain do not relate to the acute effects of pesticides, showing no connection to their toxicity. Improved eyesight and cognitive function are opposite effects and would not result from exposure to toxic substances. Increased energy levels and alertness are typically not symptoms of poisoning and could mislead individuals about their health, potentially delaying necessary treatment.