Any presence of anthropogenically generated compounds in the soil could be regarded as "Pollution" (ie it is "contaminated" with material that would otherwise not be there naturally). If you are more concerned with knowing the level of contamination that can be a problem (for human health, natural resources or ecologically), then see also the discussion at https://www.researchgate.net/post/Are_there_any_limits_for_treating_oily_contaminated_soil_Eg_should_treatment_reduce_hydrocarbons_to_5_4_etc_or_just_depends_on_resultant_risk
It depends on the guidelines limits of contaminated soil in the country and the region you are living in. Any concentration over these limits could be regarded as hazard.