Which of the following is considered an environmental contaminant from the metal finishing industry?

Heavy metals are considered significant environmental contaminants from the metal finishing industry because they are often used in various plating and coating processes. These metals include substances such as chromium, lead, cadmium, and nickel, which can leach into water bodies or soil, posing serious risks to both ecological systems and human health. When these heavy metals enter the environment, they do not break down easily and can accumulate over time, leading to long-term contamination issues.

In contrast, while silt can be a pollutant, it is typically not associated specifically with the metal finishing industry but rather with erosion and sedimentation issues. Nutrients, such as nitrogen and phosphorus, are primarily related to agriculture or wastewater treatment processes but not directly to metal finishing. Organic solvents, although used in various industrial processes, including surface preparation and cleaning, do not specifically characterize the toxicity and persistent nature of heavy metals associated with the metal finishing industry. Therefore, heavy metals are the most pertinent environmental contaminants in this context.