Where is Area-Wide Soil Contamination Likely to be Found?
Areas affected by smelter emissions in King, Pierce, Snohomish, and Stevens counties have a higher likelihood of arsenic and lead soil contamination than other areas of the State due to historical emissions from metal smelters located in Tacoma, Harbor Island, Everett, Northport, and Trail, BC. Areas where apples and pears were historically grown have a higher likelihood of arsenic and lead soil contamination than other areas of the State because of past use of lead arsenate pesticides. Chelan, Spokane, Yakima, and Okanogan counties have a higher likelihood than other counties for elevated levels of lead and arsenic in soil based on the greater numbers of apple and pear trees in production there between 1905 and 1947. Combustion of leaded gasoline produces lead-enriched particulates and aerosols that are emitted from exhaust pipes and deposited onto nearby soils. The full extent of area-wide soil contamination from past use of leaded gasoline in Washington is not known; however, in gen
