An estimated 229 000 m3 of coal fly ash remains in the river system after dredging to clean-up the 2008 Tennessee Valley Authority (TVA) spill in Kingston, Tennessee. The ash is heterogeneous with clear, orange and black spheres and non-spherical amorphous particles. Combustion produces iron oxides that allow low field magnetic susceptibility (χLF) and percent frequency dependent susceptibility (χFD%) to be used to discriminate between coal fly ash and sediments native to the watershed. Riverbed samples with χLF greater than 3.0 × 10−6 m3/kg, have greater than 15% ash measured by optical point counting. χLF is positively correlated with total ash, allowing ash detection in riverbed sediments and at depth in cores. The ratio of ash sphere composition is altered by river transport introducing variability in χLF. Measurement of χLF is inexpensive, non-destructive, and a reliable analytical tool for monitoring the fate of coal ash in this fluvial environment.

Although a great deal is known about the deposition of fluoride on vegetation, and the hazards associated with uptake by grazing herbivores, little is known about what happens to the concentration of fluoride in vegetation and soil at polluted sites once deposition ceases. The closure of Anglesey Aluminium Metals Ltd smelter, in September 2009, provided a unique opportunity to study fluoride loading once deposition stopped. Fluoride was monitored in plants and soil within 1 km of the former emission source. Fluoride concentrations in a range of plant material had decreased to background levels of 10 mg F kg−1 after 36 weeks. Concentrations of fluoride in mineral-rich soils decreased steadily demonstrating their limited potential to act as contaminating sources of fluoride for forage uptake. There were significant differences in the rate of decline of fluoride concentrations between plant species.

Summer minima and autumn/winter maxima in nitrate concentrations in rivers are reputedly due to high plant uptake of nitrate from soils in summer. A novel alternative hypothesis is tested here for soils under grass. By summer, residual readily mineralizable plant litter from the previous autumn/winter is negligible and fresh litter input low. Consequently little mineral-N is produced in the soil. Water-soluble and KCl-extractable mineral N in fresh soils and soils incubated outdoors for 7 days have been monitored over 12 months for soil transects at two permanent grassland sites near York, UK, using 6 replicates throughout. Vegetation-free soil is shown to produce very limited mineral-N in summer, despite the warm, moist conditions. Litter accumulates in autumn/winter and initially its high C:N ratio favours N accumulation in the soil. It is also shown that mineral-N generated monthly in situ in soil substantially exceeds the monthly mineral-N inputs via wet deposition at the sites.

Methods for determining bioavailability of organic contaminants suffer various operational limitations. We explored the use of stable isotope labeled references in developing an isotope dilution method (IDM) to measure the exchangeable pool (E) of pyrene and bifenthrin as an approximation of their bioavailability in sediments. The exchange of deuterated bifenthrin or pyrene with its native counterpart was completed within 48 h. The derived E was 38–82% for pyrene and 28–59% for bifenthrin. Regression between E and the sum of rapid and slow desorption fractions obtained from sequential desorption showed a slope close to 1.0. The ability of IDM to predict bioavailability was further shown from a strong relationship (r2 > 0.93) between E and bioaccumulation into Chironomus tentans. Given the abundance of stable isotope labeled references and their relatively easy analysis, the IDM has the potential to become a readily adoptable tool for estimating organic contaminants bioaccessibility in various matrices.

The occurrence and distribution of five groups of antibiotics were investigated in the surface water of Yangtze Estuary over four seasons. Of the 20 antibiotics, only sulfamerazine was not detected at all sampling sites, indicating widespread occurrence of antibiotic residues in the study area. Detection frequencies and concentrations of antibiotics were generally higher in January, indicating that low flow conditions and low temperature might enhance the persistence of antibiotics in water. Antibiotic levels varied with location, with the highest concentrations being observed around river discharge and sewage outfall. Furthermore, a positive correlation between total antibiotic and DOC concentrations revealed the significant role played by DOC. Risk assessment based on single compound exposure showed that sulfapyridine and sulfamethoxazole could cause medium risk to daphnid in the Yangtze Estuary.

A recently developed modified polar organic chemical integrative sampler (POCIS) provides a means for monitoring perfluorinated chemicals (PFCs) in water. However, changes in external flow rates may alter POCIS sampling behaviour and consequently affect estimated water concentrations of analytes. In this work, uptake kinetics of selected PFCs, over 15 days, were investigated. A flow-through channel system was employed with spiked river water at flow rates between 0.02 and 0.34 m s−1. PFC sampling rates (Rs) (0.09–0.29 L d−1 depending on analyte and flow rate) increased from the lowest to highest flow rate employed for some PFCs (MW ≤ 464) but not for others (MW ≥ 500). Rs's for some of these smaller PFCs were increasingly less sensitive to flow rate as this increased within the range investigated. This device shows promise as a sampling tool to support monitoring efforts for PFCs in a range of flow rate conditions.

Food quality affects the food consumption rate, flux through the gut, and exposure to contaminants in animals. This study evaluated the effects of food quality on cadmium exposure in the soil collembolan Folsomia candida. Animals were exposed to constant concentrations of cadmium for 38 h via artificial food consisting of an agar medium with various concentrations of sugar (glucose), total nutrients (baker's yeast), or fungal odour (1-octen-3-ol). The expression of the gene encoding a deduced metallothionein-like motif containing protein was used as a biomarker of cadmium exposure. Glucose concentrations of 2% or higher reduced the expression levels of the biomarker. Within the range of 0.1–8% yeast, medium concentrations led to higher biomarker levels. At high concentrations of 1-octen-3-ol (2000 mg/l), feeding and the biomarker response were reduced. These results suggest that even at equivalent cadmium concentrations, food quality affects cadmium exposure by altering food consumption rates.

We quantitatively describe the impacts of urbanization on the accumulation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in urban soils as well as their health risks to residents. Residential building age, population density, road density, and distance from urban center were used as urbanization level indicators. Significant correlations were found between those urbanization indicators and the amounts of PAHs, Cu, Cd, Pb, Zn and As in residential soils. The exposure time of soils to urban air was the primary factor affecting soil pollution, followed by local road density and population density. Factor analysis suggested that 59.0% of the elevated pollutant concentrations were caused by citywide uniform deposition, and 15.3% were resulted from short-range deposition and/or non-combustion processes. The combined health risks posed by soil PAHs and HMs were aggravated with time and can be expressed as functions of residence age, road density, and other urbanization indicators.

Many phenols are known to mimic or antagonize hormonal activities and may adversely affect fetal growth. A study of 567 pregnant women was conducted to investigate the relationship between prenatal phenol exposure and birth outcomes, including birth weight, length, and gestational age. We measured the concentrations of bisphenol A, benzophenone-3, 4-n-octylphenol and 4-n-nonylphenol in maternal urine and examine their association with birth outcomes. Categories of urinary benzophenone-3 concentration were associated with decreased gestational age in all infants (p for trend = 0.03). Between middle and low exposure groups, we also found bisphenol A was negatively associated with gestational duration (βadjusted = −0.48 week; 95% confidence interval: −0.91, −0.05). After stratification by gender, we found the consistent results in infant boys with those in all infants, but we did not observe significant association for girls. In conclusion, we found prenatal phenol exposure was sex-specifically related to birth outcomes.

The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by δ15N values) and dietary exploitation of particular systems (using δ13C and δ34S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 μg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 μg/g, range: 0.16–12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with δ34S values), whereas trophic position played a minor role in determining pollutant body burdens.