Spatial and temporal distribution of lead, copper, and zinc in sediments of East Fork Wetland, Seagoville, TX.

This study evaluated concentrations of three metals: lead, copper and zinc in sediments of East Fork Wetland, in Seagoville, Texas. Sediments were collected during June 2013, December 2013, and March 2014 from 138 different sites during each sampling event. Analytes were quantified using inductively coupled plasma mass spectrometry following acid digestion of samples. Average lead and zinc concentrations in interval 1 were higher than interval 3. Copper concentrations showed no seasonal variation. Average concentrations of all metals were lower than consensus based sediment quality guideline (SQG) thresholds. SQG consist of threshold effect concentration (TEC), below which harmful effects on benthic organisms are unlikely and probable effect concentration (PEC), above which adverse effects are expected to occur frequently. Approximately 98% of the individual concentrations were below TEC and 42% of data were 50% below TEC. No individual concentrations exceeded PEC levels, therefore sediments can be considered to have low toxicity.