This study investigates the passive-control-potentials of trees and on-street parked cars on pedestrian exposure to air pollutants in a street canyon using three-dimensional CFD. Since, according to some studies trees deteriorate air quality and cars parked roadside improve it, the combine as well as separate effects of trees and on-street parked cars have been examined. For this, different tree canopy layouts and parking configurations have been developed and pedestrian exposure for each has been analysed. The results showed, for example, tree crown with high porosity and low-stand density in combination with parallel or perpendicular car parking reduced the pedestrian exposure considerably.

We found that up to 52 ± 17% of residential litterfall carbon (C) and nitrogen (N; 390.6 kg C and 6.5 kg N ha−1 yr−1) is exported through yard waste removed from the City of Boston, which is equivalent to more than half of annual N outputs as gas loss (i.e. denitrification) or leaching. Our results show that removing yard waste results in a substantial decrease in N inputs to urban areas, which may offset excess N inputs from atmospheric deposition, fertilizer application and pet waste. However, export of C and N via yard waste removal may create nutrient limitation for some vegetation due to diminished recycling of nutrients. Removal of leaf litter from residential areas disrupts nutrient cycling and residential yard management practices are an important modification to urban biogeochemical cycling, which could contribute to spatial heterogeneity of ecosystems that are either N limited or saturated within urban ecosystems.

Climate projections over the next century include disproportionately warmer nighttime temperatures (“asymmetrical warming”). Cool nighttime temperatures lower metabolic rates of aquatic ectotherms. In contaminated waters, areas with cool nights may provide thermal refugia from high rates of daytime contaminant uptake. We exposed Cope's gray tree frogs (Hyla chrysoscelis), southern leopard frogs (Lithobates sphenocephalus), and spotted salamanders (Ambystoma maculatum) to five concentrations of a mixture of cadmium, copper, and lead under three to four temperature regimes, representing asymmetrical warming. At concentrations with intermediate toxicosis at test termination (96 h), temperature effects on acute toxicity or escape distance were evident in all study species. Asymmetrical warming (day:night, 22:20 °C; 22:22 °C) doubled or tripled mortality relative to overall cooler temperatures (20:20 °C) or cool nights (22:18 °C). Escape distances were 40–70% shorter under asymmetrical warming. Results suggest potentially grave ecological impacts from unexpected toxicosis under climate change.

This study evaluated the occurrence of 36 PPCPs in urban river water samples collected from Beijing, Changzhou and Shenzhen. Twenty-eight compounds were detected. Compounds found with highest median concentrations included: sulfadimethoxine (164 ng/L), sulpiride (77.3 ng/L), atenolol (52.9 ng/L), and indomethacin (50.9 ng/L). Antibiotic was the predominant class detected and contributed about half of the overall PPCPs contamination level. Effluents from wastewater treatment plants (WWTPs) were demonstrated to be the predominant pathways through which PPCPs entering into aquatic environment in all investigated areas. The ratio of persistent PPCPs like sulpiride and carbamazepine was identified to be feasible in tracing their contamination sources in rivers. Concentrations of most detected PPCPs showed significant positive correlations with total nitrogen and total phosphorus. Two groups of representative PPCPs were selected as the chemical indicators for predicting the overall PPCPs contamination, based on the significant correlations between PPCPs.

To Date, the knowledge on relationship between PCBs/PBDEs exposure and thyroid hormones (THs) levels during pregnancy still needs to be extended. Meanwhile, studies on congener-specific adipose-serum ratios for PCBs/PBDEs were limited. This study reports the levels of PCBs/PBDEs in serum-adipose tissue samples (n = 64) from expectant women living surrounding e-waste recycling sites in Wenling, China. Their concentrations varied from several to hundreds of ng g−1 lipid. Maternal exposure to PCBs was associated with lower TSH during pregnancy, suggesting possible implication for maternal health and fetal development. The compound levels between the adipose tissue and matched serum samples were highly correlated (p < 0.001), generating a predicted adipose-serum partitioning relationship for individual PCB congener and PBDE congener. Molecular characteristics, such as Kow value, molecular weight and molecular volume, may play a key role in the variable partitioning of some compounds between serum and adipose tissue.

This study investigates the dispersion and transport of reactive pollutants in a deep urban street canyon with an aspect ratio of 2 under neutral meteorological conditions using large-eddy simulation. The spatial variation of pollutants is significant due to the existence of two unsteady vortices. The deviation of species abundance from chemical equilibrium for the upper vortex is greater than that for the lower vortex. The interplay of dynamics and chemistry is investigated using two metrics: the photostationary state defect, and the inferred ozone production rate. The latter is found to be negative at all locations within the canyon, pointing to a systematic negative offset to ozone production rates inferred by analogous approaches in environments with incomplete mixing of emissions. This study demonstrates an approach to quantify parameters for a simplified two-box model, which could support traffic management and urban planning strategies and personal exposure assessment.

Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans.

Endocrine disrupting compounds (EDCs) like bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) are introduced to the trophic webs through among others phytoplankton. This paper describes BPA, OP and NP concentrations in phytoplankton in the Gulf of Gdansk (Southern Baltic Sea) in the years 2011–2012. The assays of BPA, OP and NP in samples were performed using HPLC with fluorescence detection. The concentrations of BPA, the most commonly used of the three compounds, were over ten times higher than OP and NP concentrations. The concentrations of the studied EDCs in phytoplankton from the Gulf of Gdansk depended on anthropogenic factors and on phytoplankton properties (species composition, biomass, volume). An increase in phytoplankton biomass did not always result in an increase of BPA, OP and NP concentrations. However, the load of the studied EDCs accumulated in phytoplankton biomass increase with a rise of biomass. An increase in BPA, OP and NP concentrations was effected by biomass growth and the proportions ofciliates, dinoflagellates, diatoms and green algae. A strong positive correlation between OP and NP concentrations and negative correlation between BPA concentrations and biomass of organisms with cells measuring <1000 μm3 in volume results from the differing properties of these compounds.

Arsenic, cadmium and lead in aerosols, dusts and surface soils from Australia's oldest continuous lead mining town of Broken Hill were compared to standardised national childhood developmental (year 1) and education performance measures (years 3,5,7,9). Contaminants close to mining operations were elevated with maximum lead levels in soil: 8900 mg/kg; dust wipe: 86,061 μg/m2; dust deposition: 2950 μg/m2/day; aerosols: 0.707 μg/m3. The proportion of children from Broken Hill central, the area with the highest environmental contamination, presented with vulnerabilities in two or more developmental areas at 2.6 times the national average. Compared with other school catchments of Broken Hill, children in years 3 and 5 from the most contaminated school catchment returned consistently the lowest educational scores. By contrast, children living and attending schools associated with lower environmental contamination levels recorded higher school scores and lower developmental vulnerabilities. Similar results were identified in Australia's two other major lead mining and smelting cities of Port Pirie and Mount Isa.

The effects of chironomid larvae bioturbation on the lability of phosphorus (P) in sediments were investigated through sediment incubation for 140 days. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were applied to obtain soluble and labile P/Fe profiles at a millimeter resolution, respectively. The larvae bioturbation decreased concentrations of soluble/labile P and Fe by up to over half of the control at the sediment depths of influence up to 70 and 90 mm respectively. These effects continued over 116 days and disappeared on the 140th days due to eclosion of chironomid larvae. Labile P was highly correlated with labile Fe, while a weak correlation was observed between soluble P and soluble Fe. It was concluded that Fe(II) oxidation and its enhanced adsorption were the major mechanisms responsible for the decreases of soluble and labile P.