Submitted to: Environmental Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2011
Publication Date: 1/5/2012
Publication URL: http://dx.doi.org/10.1016/j.envpol.2011.09.020
Citation: Lozano, N., Rice, C., Ramirez, M., Torrents, A. 2012. Fate of triclosan and methyltriclosan in soil from biosolids application. Environmental Pollution. 160:103-108. Interpretive Summary: Triclosan is a major use bacteriostat contained in many household products and a major portion of this material is discharged in biosolids from waste water treatment plants. Because of the possibility that this material might have environmental effects, its environmental fate is important to understand. To address this environmental concern, the soil release and fate of triclosan and methyltriclosan (MeTCS), an important degradate, was followed for three years after a single biosolid application. Concentration of TCS in the soil gradually increased with maximum levels reaching 63.7 ± 14.1 ng g-1 dry wt two months after application. TCS disappearance corresponded with MeTCS appearance, suggesting in-situ biodegradation. The results suggest that soil incorporation and degradation processes are taking place simultaneously and that TCS background levels are achieved within two years. TCS dissipation half-live was determined as 104 d and the MeTCS halflife was longer, 443 d.
Technical Abstract: Biosolids contain synthetic chemicals that have the potential to alter soil microbial communities and disrupt endocrine functions if they move offsite. The persistence of triclosan (TCS), an antibacterial compound normally found in biosolids and in soils after biosolids applications was evaluated. The fate of its biodegradation product, Methyltriclosan (MeTCS), was also examined. Surface soil samples were collected several times over a three year period after a single biosolid application. Concentration of TCS in the soil gradually increased with maximum levels of 63.7 ± 14.1 ng g-1 dry wt., far below the predicted maximum concentration of 307.5 ng g-1 dry wt. TCS disappearance corresponded with MeTCS appearance, suggesting in-situ biodegradation. The results suggest that soil incorporation and degradation processes are taking place simultaneously and that TCS background levels are achieved within two years. TCS half-live (t0.5) was determined as 104 d and MeTCS t0.5, which was more persistent than TCS, was estimated at 443 d.