Which characteristic of pesticides affects their potential environmental harm?

The selectivity of pesticides towards certain pests is a crucial characteristic that directly influences their potential environmental harm. Selective pesticides target specific organisms while minimizing impact on non-target species. This selectivity helps preserve beneficial insects, plants, and other wildlife within the ecosystem, reducing the overall ecological footprint of pesticide application.

In contrast, pesticides that lack selectivity can harm non-target organisms, leading to unwanted consequences such as loss of biodiversity, disruption of food webs, and contamination of surrounding habitats. This characteristic is fundamental when considering not just the efficacy of a pesticide against pests, but also its broader implications for environmental health.

The other characteristics mentioned—color and smell, price and availability, and popularity among farmers—do not inherently reflect the environmental impact of pesticides. While these factors can influence choice and usage, they are not directly tied to the potential harm pesticides can cause to the environment.