Toxicity of construction materials in the marine environment: a comparison of chromated-copper-arsenate-treated wood and recycled plastic.

Previous studies have demonstrated leaching from chromated-copper-arsenate (CCA)-treated wood, which is used in pilings and bulkheads, and resulting toxicity to various estuarine organisms. The current study compared effects of leachates from CCA-treated wood with those of recycled plastic "lumber," a possible alternative construction material. Limb regeneration in fiddler crabs, while depressed in leachates from CCA wood, was accelerated in three formulations of recycled plastics. The acceleration was reduced in subsequent trials with the same pieces of plastic. Using a sea urchin fertilization test, no effects were seen in 1- and 3-day leachates from the plastics. However, CCA wood reduced fertilization by 90%, and totally inhibited larval development of those that did fertilize. A smaller piece of wood, one-tenth the size (0.4 cm2), did not have a significant effect on fertilization or development. With 1-3 weeks of leaching, significant reductions in fertilization were seen in sea urchin gametes exposed to one plastic formulation and no fertilization was seen in leachates from the small piece of CCA wood. Two formulations enriched to 30% polystyrene (PS) had no significant effect on fertilization, but did reduce larval growth. When the same pieces of plastic and wood were used for a second set of experiments, all three formulations of plastic, as well as the small piece of wood, inhibited fertilization significantly, and one of the 30% PS formulations and the wood caused reduced larval growth. In another assay, snails and an alga were exposed to plastics for two months with no observed effect; the CCA leachates caused 100% snail mortality within one week and chlorosis of the alga.(ABSTRACT TRUNCATED AT 250 WORDS)