Industrial impact in Northwestern Whatcom County,Washington

A field study designed to determine the nature and extent of environmental impact by an industrial complex was carried out during the period 1966–76. The industrial complex consists of two oil refineries, Mobil and Atlantic Richfield (ARCO), and an aluminium reduction plant, Intalco. The location is northwestern Whatcom County, Washington, U.S.A. The study consisted of critical examination of native, exotic, and cultivated plants in 75 sites; productivity analysis at two sites; plant community analysis at three sites; total-S analysis of leaves at 37 sites; and soil S analysis at 10 sites. The effect of SO₂ emission by Mobil and ARCO appeared to be negligible, except in regard to injury to lichens and bryophytes; however S accumulation was strongly correlated with distance from the refineries, wind pattern, and ambient air concentrations of SO₂. Hydrogen fluoride is an established pollutant from Intalco and is thought to have reacted synergistically with SO₂ to produce injury symptoms at S concentrations below reported injury threshold levels.