Which of the following substances is most likely to be considered a pollutant when released?

Petroleum products are considered pollutants when released into the environment due to their harmful effects on ecosystems, human health, and the environment as a whole. These substances can contaminate soil, water, and air, leading to significant ecological damage. The toxicity of petroleum products can disrupt aquatic life, poison wildlife, and affect the quality of drinking water supplies. Their presence can lead to long-term environmental issues, such as oil spills that require intensive cleanup efforts.

In contrast, clean water, ordinary soil, and compressed air typically do not pose the same environmental risks when released. Clean water is essential for life and is not considered a pollutant unless contaminated. Ordinary soil plays a vital role in the ecosystem and does not inherently harm the environment. Compressed air, when released, generally disperses rapidly and does not have lasting harmful effects. Thus, petroleum products stand out as substances that are likely to be classified as pollutants due to their detrimental impacts on environmental health.