Degradation of Pharmaceutical and Industrial Compounds In Soil.

Pharmaceutical compounds and chemicals incorporated into consumer products are ubiquitous in the environment due to widespread use. In the environment, their effects may range from neutral to negative. Specific knowledge of their behavior is necessary to understand their environmental impact. The degradation of two 14C-radiolabeled pharmaceuticals, diclofenac and naproxen, as well as two 14C-radiolabeled compounds from industry, the plastic additive bisphenol A and the surfactant breakdown product nonylphenol, were studied. Five soil conditions were used to examine the rate of microbial degradation and the tendency of the compounds to form bound residues. The Maricopa soil, from the Gilbert Riparian Preserve, was collected from basins used for decades to recharge groundwater with reclaimed water. The Irvine and Ventura soils were collected from University of California Agricultural Extension Sites. Two more conditions were created from the Irvine soil by either sterilization or amendment with compost. Mineralization rates for the compounds followed the decreasing order naproxen > diclofenac > bisphenol A > nonylphenol. Sterilized soil exhibited significantly reduced mineralization rates for all compounds.