Arsenic Addition to Soils from Airborne Coal Dust Originating at a Major Coal Shipping Terminal

Abstract

Soil samples were collected from Norfolk, Virginia in order to examine the extent of particulate coal, and associated arsenic (As) deposition to local soils. The particulate coal originates from the adjacent coal shipping terminal at the Lambert’s Point Docks, which is the largest marine coal shipping terminal in the Northern Hemisphere. Particulate coal was separated from soil samples using heavy liquid (i.e., sodium polytungstate) extraction. Sand-sized coal separates isolated from the soil samples were subsequently digested using concentrated nitric and sulfuric acid, and analyzed for As by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Selected total soil digests were also analyzed for As by HR-ICP-MS. Results indicate particulate coal ranges from less than 1% up to ∼20%, by weight, of the soil samples analyzed. Arsenic concentrations in sand-sized particulate coal extracted from these sediments range from undetectable levels (i.e., <3 ng/kg) up to 17.4 mg/kg, whereas total As concentrations in the soils range from 3 to 30.5 mg/kg. The data indicate that particulate coal originating at the Lambert’s Point Docks is an additional source of As to local soils, especially sites proximal to the shipping terminal. Although the particulate coal itself likely poses only minor health hazards (if any), the environmental consequences of As transported with the particulate coal is not known.