Secondary pollutant impacts from emissions of single sources may need to be assessed to satisfy a variety of regulatory requirements including the Clean Air Act New Source Review and Prevention of Significant Deterioration programs and the National Environmental Policy Act. In this work, single source impacts on O3 and secondary PM2.5 are estimated with annual 2011 photochemical grid model simulations where new hypothetical sources are added to the central and eastern United States with varying precursor emission rates and emission release heights. Impacts from these hypothetical sources are tracked with photochemical grid model source apportionment. Single source impacts on downwind 8-hr maximum O3 tend to increase as emissions of NOX or VOC increase. Downwind impacts on PM2.5 sulfate and nitrate also tend to increase as emissions of SO2 and NOX increase. For all secondary pollutants, impacts from these hypothetical sources tend to decrease as distance from the source increases. However, peak impacts on O3 and secondary PM2.5 are not at the facility fence-line but typically within 50–100 km depending on the emissions rate, precursor pollutant, and emissions release point. Downwind impacts are not uniform directionally from these sources due to varying downwind availability of chemical reactants and prevailing meteorology. Peak impacts for O3 (∼15 ppb) and PM2.5 sulfate (∼8 μg/m3) were within 50 km of these hypothetical sources and peak impacts for PM2.5 nitrate (∼1 μg/m3) were within 125 km. The daily maximum 8-hr O3 and maximum daily average PM2.5 sulfate and nitrate ion impacts for the new hypothetical sources modeled here are generally consistent with those reported in literature. Additional assessments of single source impacts on secondary pollutants are still needed to provide a more comprehensive assessment of different source types and source environments.

Passive air samplers (PAS) have become recurrent methods for environmental monitoring. However, the influence of environmental variables, such as temperature, over these devices has not been fully investigated. Since climate change is likely to induce major environmental changes, the role of the temperature needs to be studied to assure the suitability of PAS for the long-term monitoring of semi-volatile organic compounds (SVOCs) and their utility to compare data from different locations. This study aimed at evaluating the potential loss of polycyclic aromatic hydrocarbons (PAHs) in PAS containing disks of polyurethane foam (PUF) at different temperatures. The gradient of temperature inside and outside the PAS was firstly determined, being noted an internal/external difference of up to 5 °C. Secondly, a lab-controlled experiment was performed by daily analyzing PAHs in PUF-based PAS exposed to 25 °C and 38 °C, for a period of 7 days. A significant loss of PAHs in PUFs was not observed for any of both scenarios, remaining constant through time. Moreover, PAH levels were not significantly different according to the temperature. These findings indicate that the environmental temperature does not affect the stability of PAHs in PAS. Once PAHs have been uptaken, they are not easily volatilized from these devices. Consequently, PAS are good environmental monitors independently on the ambient conditions of temperature, being suitable for the comparability of data, either temporally or spatially, on the airborne concentrations of PAHs.

A reliable identification of sources and their relative time dependent contributions to ambient aerosol load is an important air pollution research problem. Given the inherent complexity of contributing sources in urban/mega-cities, an appropriate statistical investigation is needed to characterize sources and to understand their timeline trend profiles. Daily average ambient particulate matter (PM) loads, PM10 (aerodynamic diameter <10 μm) and coarser particulate matter (CPM: aerodynamic diameter >10 μm) were collected once a week over 4 years at a receptor site in Delhi. The samples were analyzed to quantify the presence of 17 marker elements. Time series data of PM loads, and that of associated marker elements was subjected to Positive Matrix Factorization (PMF) to identify sources and to quantify their contributions to each PM fraction with reference to the associated marker elements. The resolved time series data of each contributing source was further subjected to Ensemble Empirical Mode Decomposition (EEMD) analysis to extract their timeline trend profile over four years in CPM and PM10 load. Three sources contributed to the CPM load: anthropogenic (15%), primary crustal (59%), and fine crustal dust (26%). Four sources contributed to the PM10 load: coarser grain crustal material (9%), fine grain crustal material (12%), industrial and vehicular emissions (23%), and wind assisted transport and re-suspension of surface dust (56%). The timeline trend of sources contributions to CPM and PM10 displayed a non-linearity. The unique composite-PM10 source contributed maximum to the ambient PM10 load. Distinct underlying processes of this source involved convective re-suspension and city-wide cleaning associated upliftment of surface deposits back into the ambient environment.

Black carbon (BC) and tropospheric ozone (O3) are two main short-lived climate pollutants also linked to health effects. They are ubiquitous in street canyons, since this environment is a hotspot for traffic-related pollutants due to their particular airflow characteristics, location within the cities and the high density of vehicles and population.We report on BC and O3 concentrations measured in a Brazilian city in November 2014. Measurements of BC at 880 nm wavelength were conducted in a street canyon on the north and south façades and at rooftop level (7 wavelengths, including 880 nm) whereas O3 was recorded only on the south façade. Concurrent meteorological data were gathered at a suburban and a rooftop sites.Clear diurnal patterns were found for BC related to traffic emissions and atmospheric mixing conditions. Ozone peaked in the afternoon in response to maximum photochemical production and at night most likely linked to vertical and/or horizontal transport. By using conditional bivariate probability functions, we identified on-road traffic as the main local source for BC during daytime, and at night an intermittent signal was associated with local waste and biomass burned on the city's outskirts. A complementary air backward trajectory analysis helped conclude that locally produced O3 was enhanced by regional transport from large cities and/or biomass smoke.Mitigation strategies for BC and O3 depletion should target the vehicle fleet, particularly diesel buses, reduction of biomass and waste burning at local level, and decrease of open biomass burning in large areas in Brazil and neighbor countries.

δ15N of annual (Ulva sp., Porphyra sp.) and perennial intertidal seaweed species (Chondrus crispus, Fucus sp.) collected on 17 sampling points along the French coast of the English Channel in 2012 and 2013 were assessed on their suitability as bioindicators of N pollution in coastal areas. A sine function applied for δ15N time series data showed for all the species the same seasonal trend with lowest δ15N values in April and highest in summer but with no significant interspecific differences of amplitude (α) and phase angle (ϕ). This model provides a useful tool for monitoring the inter-annual changes of N pollution. An interspecific variability of δ15N values was observed, probably due to their tolerance to emersion. An in vitro study for comparing the kinetic acquisition of the isotopic signal and N uptake mechanisms of each species underlined the influence of algal physiology on the δ15N interspecific variability.

A multidisciplinary survey was carried out on the quality of water and sediments of a coastal protected marine area, embedded between the inputs from Bagnoli steel plant to the south and a sewage plant, Volturno River and Regi Lagni channel to the north. The study integrated chemical-sedimentological data with biological and ecotoxicological analyses to assess anthropogenic pressures and natural variability. Data reveal marked differences in anthropogenic pollution between southeastern and northwestern zone, with the north affected by both inorganic and organic flows and the south influenced by levels of As, Pb and Zn in the sediments above law limits, deriving from inputs of the Bagnoli brownfield site. Meiobenthic data revealed at south higher relative abundance of sensitive species to pollution and environmental stress to the south, i.e. Lobatula lobatula and Rosalina bradyi, whereas to the north relative abundance of stress tolerant Quinqueloculina lata, Quinqueloculina pygmaea and Cribroelphidium cuvilleri were determined.

Rapid assessment sampling for target species is a fast cost-effective method aimed at determining the presence, abundance and distribution of alien and native harmful aquatic organisms and pathogens that may have been introduced by shipping. In this study, the method was applied within a large tropical port expected to have a high species diversity. The port of Kaohsiung was sampled for bivalve molluscan species that attach using a byssus. Such species, due to their biological traits, are spread by ships to ports worldwide. We estimated the abundance and distribution range of one dreissenid (Mytilopsis sallei) and four mytilids (Brachidontes variabilis, Arcuatula senhousa, Mytilus galloprovincialis, Perna viridis) known to be successful invaders and identified as potential pests, or high-risk harmful native or non-native species. We conclude that a rapid assessment of their abundance and distribution within a port, and its vicinity, is efficient and can provide sufficient information for decision making by port managers where IMO port exemptions may be sought.

Strong winds and storm surges from Typhoon Haiyan caused damage of US$12–15billion and >10,000 human casualties in central Philippines in November 2013. To validate a proposed government US$22million mangrove replanting program, mangrove damage and short-term recovery were surveyed in seven natural and planted mangrove sites in Eastern Samar province at 2.5month and 4.5month post-Haiyan. The preliminary assessment showed that natural mangroves (except for those directly hit by the storm) were recovering by means of tree sprouts and surviving seedlings and saplings compared to the devastated plantation. Likewise, tree mortality was higher in the plantation and natural forests hit by the storm surge, compared to more undamaged and partially damaged trees in natural mangroves. Hence the main recommendations to government are (1) to protect recovering mangroves by not releasing rehabilitation funds (that will inadvertently pay for clearing of live trees and for removal of seedlings), (2) to only plant in totally damaged sites (e.g., plantations), and (3) to only plant naturally dominant species, e.g., Sonneratia alba and Avicennia marina (instead of the popular Rhizophora apiculata, R. mucronata and R. stylosa).

The sampling effort for detecting taxonomic distinctness of periphytic diatom communities was studied in coastal waters of the Yellow Sea, northern China, from May to June 2014. Samples with different sizes (microscopy glass slides) were collected at two depths of 1m and 3m. To obtain the communities with dissimilarities of <10%, 2 slide replicates were sufficient for sampling at a depth of 1m, while 4 were required for the those at a depth of 3m. The values of four taxonomic distinctness indices represented a low sensitivity to sample sizes over all exposure period ages: at a coefficient of variation of <10%, 2 and 9 slide replicates were required at a depth of 1m and 3m, respectively. We suggest that the sampling strategy of the diatoms for detecting taxonomic distinctness might be better at 1m than at a deeper layer in coastal waters.