Pesticides used on fruits and vegetables are harmful for several reasons:

1. Human Health Risks: Pesticides are designed to kill or repel pests, and they can also be toxic to humans. Exposure to pesticides can lead to a variety of health issues, ranging from short-term impacts like headaches and nausea to long-term effects like cancer, reproductive harm, and endocrine disruption.

2. Residual Effects: Pesticides can remain on, and in, fruits and vegetables after they are harvested. While washing and peeling can reduce residues, they don’t eliminate them completely. Certain pesticides are known to persist on produce even after washing.

3. Bioaccumulation and Biomagnification: Some pesticides can accumulate in the body over time, and they can become more concentrated as they move up the food chain. This can pose significant health risks to higher-level predators, including humans.

4. Vulnerable Populations: Certain populations, such as children, pregnant women, and the elderly, are more susceptible to the harmful effects of pesticide exposure. Even low levels of pesticide exposure can be more harmful to these groups.

Consumers can also reduce their exposure by buying organic produce, washing fruits and vegetables thoroughly, and diversifying their diet.