What are the most common chemicals involved in soil pollution?

• A. Petroleum hydrocarbons, heavy metals, pesticides, and solvents
• B. Pesticides and plastics
• C. Salt and chlorine
• D. Radioactive elements

Answer: (A)

In soil pollution, the most common chemicals come from everyday human activity across energy, industry, and agriculture. Petroleum hydrocarbons from fuel leaks and spills persist in soils and can migrate into groundwater. Heavy metals such as lead, cadmium, and arsenic accumulate in soils from mining, metalworking, batteries, paints, and certain fertilizers; they don’t biodegrade and can remain for long periods, posing long-term risks to organisms and ecosystem functions. Pesticides used in agriculture frequently bind to soil particles and can persist, especially in soils with limited microbial activity, leading to ongoing exposure for soil life and potential runoff into water. Solvents from manufacturing and cleaning can leave residues that dissolve and transport contaminants and disrupt soil microbial processes.

Other options are less representative of what’s most commonly found in polluted soils. Plastics are a major pollution concern but are not individual chemicals in the same sense and are more about particulates and additives; salts and chlorine relate mainly to soil salinity rather than broad chemical contamination; radioactive elements are only common at specific sites, not across typical soil pollution scenarios.