Despite common knowledge that the metal content adsorbed by fine particles is relatively higher compared to coarser particles, the reasons for this phenomenon have gained little research attention. The research study discussed in the paper investigated the variations in metal content for different particle sizes of solids associated with pollutant build-up on urban road surfaces. Data analysis confirmed that parameters favourable for metal adsorption to solids such as specific surface area, organic carbon content, effective cation exchange capacity and clay forming minerals content decrease with the increase in particle size. Furthermore, the mineralogical composition of solids was found to be the governing factor influencing the specific surface area and effective cation exchange capacity. There is high quartz content in particles >150 μm compared to particles <150 μm. As particle size reduces below 150 μm, the clay forming minerals content increases, providing favourable physical and chemical properties that influence adsorption.

Aminocyclopyrachlor is a pyrimidine carboxylic acid herbicide used to control broadleaf weeds and brush. Amending soil with activated charcoal is recommended to prevent off-site transport of aminocyclopyrachlor and non-target plant damage. We used the batch-equilibrium method to determine the concentration of aminocyclopyrachlor in a pseudo-steady state with biochar, soil, and biochar-soil systems (<10% biochar by weight). We observed that aminocyclopyrachlor is mobile in soils. Soil incorporation of activated charcoal removed nearly all of the aqueous aminocyclopyrachlor thereby limiting its bioavailability to non-target flora. On the other hand, biochars were less effective than activated charcoal. Biochar produced from olive mill waste feedstock was the most effective biochar that we assessed for reducing the aqueous herbicide concentration. Although these biochars reduced the aminocyclopyrachlor concentration, they would not be practical remediation media due to the extraordinarily high application rates required to reduce the concentration by 50% (2.13 × 105 kg ha−1–7.27 × 105 kg ha−1).

Near-freeway environments are important from public health and environmental justice perspectives. This study investigated the spatial profile of and correlations between noise levels and particulate matter concentrations near two major freeways in Los Angeles, CA. Five minutes averages of A-weighted equivalent continuous sound level (LeqA), ultrafine particle (UFP) number concentrations, and fine particle (PM2.5) mass concentrations were measured concurrently at increasing distances from the freeways on four streets with or without sound wall. Under upwind conditions, UFP showed relatively low concentrations and no obvious gradient, while LeqA showed decay with increasing distance as it did under downwind conditions. Moderate correlations between LeqA and UFP were observed under downwind conditions on all four streets. The presence of a sound wall changed the linear relationship between LeqA and UFP. These data may be used to study the independent and synergistic health impacts of noise and air pollutants near roadways.

The WHAM-FTOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (FTOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H+ < Al < Cu < Zn < Ni. In general, observed species richness is lower than predicted, but in some instances agreement is close, and is rarely higher than predictions. The model predicts recovery in agreement with observations for three regions, namely Sudbury (Canada), Bohemian Forest (Czech Republic) and a subset of lakes across Norway, but fails to predict observed recovery from acidification in Adirondack lakes (USA).

Trees remove air pollution by the interception of particulate matter on plant surfaces and the absorption of gaseous pollutants through the leaf stomata. However, the magnitude and value of the effects of trees and forests on air quality and human health across the United States remains unknown. Computer simulations with local environmental data reveal that trees and forests in the conterminous United States removed 17.4 million tonnes (t) of air pollution in 2010 (range: 9.0–23.2 million t), with human health effects valued at 6.8 billion U.S. dollars (range: $1.5–13.0 billion). This pollution removal equated to an average air quality improvement of less than one percent. Most of the pollution removal occurred in rural areas, while most of the health impacts and values were within urban areas. Health impacts included the avoidance of more than 850 incidences of human mortality and 670,000 incidences of acute respiratory symptoms.

Biomagnetic monitoring of urban tree leaves has proven to be a good estimator of ambient particulate matter. We evaluated its relevancy by determining leaf area normalised weight (mg m−2) and SIRM (A) of leaf-deposited particles within three different size fractions (>10 μm, 3–10 μm and 0.2–3 μm) and the SIRM of the leaf-encapsulated particles. Results showed that throughout the in-leaf season, the trees accumulated on average 747 mg m−2 of dust on their leaves, of which 74 mg m−2 was within the 0.2–10 μm (∼PM10) size range and 40 mg m−2 within the 0.2–3 μm (∼PM3) size range. A significant correlation between the SIRM and weight of the surface-deposited particles confirms the potential of biomagnetic monitoring as a proxy for the amount of leaf-deposited particles. Spatial variation of both SIRM and weight throughout the street canyon suggests traffic and wind as key factors for respectively the source and distribution of urban particulates.

The potential benefit of urban vegetation in reducing heat related mortality in the city of Melbourne, Australia is investigated using a two-scale modelling approach. A meso-scale urban climate model was used to quantify the effects of ten urban vegetation schemes on the current climate in 2009 and future climates in 2030 and 2050. The indoor thermal performance of five residential buildings was then simulated using a building simulation tool with the local meso-climates associated with various urban vegetation schemes. Simulation results suggest that average seasonal summer temperatures can be reduced in the range of around 0.5 and 2 °C if the city were replaced by vegetated suburbs and parklands, respectively. With the limited buildings and local meso-climates investigated in this study, around 5–28% and 37–99% reduction in heat related mortality rate have been estimated by doubling the city's vegetation coverage and transforming the city into parklands respectively.

The study aims to examine relationships between microbial community structure and mixed pollutants of polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs) in constructed wetland microcosms, planted with Excoecaria agallocha or Kandelia obovata, two common mangrove plant species, and under two tidal regimes, everyday tidal (Te) and no tidal flooding (Tn). Results showed both microbial community structure and the retained amounts of pollutants were significantly determined by tidal regime, while the effect of plant species was small. Higher amounts of PAHs but lower amounts of PBDEs were always retained in sediments under Te than Tn regimes. Accordingly, temporal and vertical distributions of microbial community structure differed greatly between the two tidal regimes. Redundancy analysis further revealed significant correlation between a subgroup of the mixed PAHs and PBDEs with variation in microbial community structure. The findings will help to propose specific strategies to improve the bioremediation efficiency of constructed wetland.

Environmental pollution by anti-influenza drugs is increasingly recognized as a threat to aquatic environments. However, little is known about empirical data on risk effects posed by environmentally relevant concentrations of anti-influenza drug based on recently published ecotoxicological researches in Taiwan. Here we linked ecotoxicology models with an epidemiological scheme to assess exposure risks of aquatic organisms and environmental hazards posed by antiviral oseltamivir (Tamiflu) use in Taiwan. Built on published bioassays, we used probabilistic risk assessment model to estimate potential threats of environmentally relevant hazards on algae, daphnid, and zerbrafish. We found that Tamiflu use was unlikely to pose a significant chronic environmental risk to daphnia and zebrafish during seasonal influenza. However, the chronic environmental risk posed by Tamiflu use during pandemic was alarming. We conclude that no significant risk to algal growth was found during seasonal influenza and high pandemic Tamiflu use.