Distribution of persistent organohalogen compounds in pine needles from selected locations in Kentucky and Georgia, USA.

Epicuticular wax of pine needles accumulates organic pollutants from the atmosphere, and the pine needle samples have been used for monitoring both local and regional distributions of semivolatile organic air pollutants. One-year-old pine needles collected from residential and industrial locations in western Kentucky and the vicinity of Linden Chemicals and Plastics, a Superfund Site at Brunswick, Georgia, were analyzed for polychlorinated biphenyls (PCBs), major chlorinated pesticides, and polychlorinated naphthalenes (PCNs). Total PCB concentrations in pine needles from Kentucky ranged from 5.2 to 12 ng/g dry weight (dw). These sites were comparatively less polluted than those from the Superfund Site, which had total PCB concentrations in pine needles in the range of 15-34 ng/g dw. Total chlorinated pesticides concentrations in pine needles ranged from 3.5 to 10 ng/g dw from Kentucky. A similar range of concentrations of chlorinated pesticides (7.3-12 ng/g dw) was also found in pine needle samples from the Superfund site. Total PCN concentrations in pine needles ranged from 76 to 150 pg/g dw in Kentucky. At the Superfund Site, total PCN concentrations ranged from 610 pg/g dw to 38,000 pg/g dw. When the toxic equivalencies (TEQs) of PCBs in pine needles were compared, Kentucky was relatively lower (0.03-0.11 pg/g dry wt) than the TEQs at the Superfund Site (0.24-0.48 pg/g dry wt). The TEQs of PCNs from Kentucky (0.004-0.067 pg/g dw) were much lower than the TEQs from locations near the Superfund Site (0.30-19 pg/g dry wt). The results revealed that pine needles are excellent, passive, nondestructive bioindicators for monitoring and evaluating PCBs, chlorinated pesticides, and PCNs.