Effects of Lead (Pb) from Smelter Operations in an Urban Terrestrial Food Chain at a Colorado Superfund Site.

Lead (Pb) is ubiquitous in urban environments, and it is a risk factor for wildlife. But wildlife are particularly at risk for exposure near smelters in urban areas where higher than safe Pb levels in the soil have the potential to transfer to the food chain. Therefore, we investigated whether wildlife are at risk of Pb exposure and differences in Pb bioaccumulation in trophic levels at a Superfund site in an urban area of Colorado.

Differential Bioaccumulation of Mercury and Selenium in Stomach Contents and Tissues of Three Colorado, USA, Cutthroat Trout Populations.

Total mercury (THg) and selenium (TSe) levels were measured in stomach contents (SC) and twelve tissues of cutthroat trout (Oncorhynchus clarkii) occurring in three high-elevation lakes of Colorado, USA, inhabiting watersheds absent past and current mining activities. For 32 of 36 tissues, including muscle, mean THg wet weight (ww) concentrations were greater than in the diet (SC) for all sites, indicating biomagnification. Ranges of THg (µg/kg ww) for SC and stomach tissue (ST) were 1.

Selenium Speciation in the Fountain Creek Watershed (Colorado, USA) Correlates with Water Hardness, Ca and Mg Levels.

The environmental levels of selenium (Se) are regulated and strictly enforced by the Environmental Protection Agency (EPA) because of the toxicity that Se can exert at high levels. However, speciation plays an important role in the overall toxicity of Se, and only when speciation analysis has been conducted will a detailed understanding of the system be possible. In the following, we carried out the speciation analysis of the creek waters in three of the main tributaries-Upper Fountain Creek, Monument Creek and Lower Fountain Creek-located in the Fountain Creek Watershed (Colorado, USA).

Selenium speciation in the Fountain Creek Watershed and its effects on fish diversity.

Se is an environmental concern as it can be toxic if present in high concentrations even though it is a dietary requirement for all animals. Se levels are a special concern in the Fountain Creek Watershed located in southeastern Colorado whose geological source is the Se-rich Pierre Shale. Segments of Fountain Creek have Se water levels that exceed the current EPA limit of 5 µg/l.

Presence and transport of the antimicrobials triclocarban and triclosan in a wastewater-dominated stream and freshwater environment.

The presence of the antimicrobials triclocarban (TCC) and triclosan (TCS)in Fountain Creek, a wastewater-dominated stream, and the Arkansas River, Colorado, USA was measured in the surface water, suspended sediments, and bed sediments during spring runoff (high flow) and summer base flow (low flow) conditions. Fountain Creak is a tributary of the Arkansas River. Passive polar organic chemical integrative samplers (POCIS) were used along with active sampling (water grab samples) to measure and TCS concentrations in these surface waters.

Arsenic, cadmium, lead, and mercury in surface soils, Pueblo, Colorado: implications for population health risk.

Decades of intensive industrial and agricultural practices as well as rapid urbanization have left communities like Pueblo, Colorado facing potential health threats from pollution of its soils, air, water and food supply. To address such concerns about environmental contamination, we conducted an urban geochemical study of the city of Pueblo to offer insights into the potential chemical hazards in soil and inform priorities for future health studies and population interventions aimed at reducing exposures to inorganic substances. The current study characterizes the environmental landscape of Pueblo in terms of heavy metals, and relates this to population distributions.