What is one of the main risks associated with the improper use of pesticides?

The development of pest resistance is a significant risk associated with the improper use of pesticides. When pesticides are used excessively or incorrectly, pests may not be entirely eliminated and those that survive can develop a resistance to those chemicals over time. This phenomenon occurs as the pests that are less susceptible to the pesticide reproduce, leading to a new generation that can withstand the chemical treatment. Over time, this can result in a population of pests that are much harder to control, necessitating the use of even stronger pesticides or alternative pest management strategies, which can further complicate pest management and potentially increase environmental impact.

The other options provided do not accurately reflect risks of improper pesticide use. Increased biodiversity is generally not associated with improper pesticide use, as misuse tends to harm non-target species and disrupt ecological balance. Enhanced crop yields and improvement of soil health are typically benefits of proper pesticide use, not consequences of improper application. Instead, improper use often leads to reduced agricultural productivity and can harm soil health due to contamination or disruption of soil organisms.