The results of three measurement campaigns are presented in this study. The campaigns have been undertaken at an urban roadside site in London, for more than a year and three months in 2003–2004 and for a year in 2008, and at an urban background site in Birmingham, U.K, for about four months in 2002. The concentrations of PM2.5, PM10, NOx and NO2 were predicted using the roadside dispersion model CAR-FMI, combined with a national U.K. emission model, a meteorological pre-processor, and measured values at urban background stations. The agreement of the predicted and measured hourly and daily time-series has been assessed statistically for all of the campaigns and pollutants. For instance, the Indices of Agreement (IA) in all the campaigns ranged from 0.68 to 0.78, 0.87, from 0.70 to 0.80, and from 0.61 to 0.83 for PM2.5, PM10, NOx and NO2, respectively. However, in case of the campaigns in London, both the PM fractions and the nitrogen oxide concentrations were under-predicted. The model performance in terms of atmospheric stability, wind speeds and other factors was analysed, and reasons for the disagreement of predictions and measurements have been discussed. It is useful to consider the model performance statistics for several measurement campaigns simultaneously, as some of the results were found to be specific only to one or two campaigns. The spatial concentration distribution of NOx in London for 2008 has also been presented.

Coral-associated bacteria play an increasingly recognized part in coral health. We investigated the effect of local anthropogenic impacts on coral microbial communities on reefs near Jeddah, the largest city on the Saudi Arabian coast of the central Red Sea. We analyzed the bacterial community structure of water and corals (Pocillopora verrucosa and Acropora hemprichii) at sites that were relatively unimpacted, exposed to sedimentation & local sewage, or in the discharge area of municipal wastewaters. Coral microbial communities were significantly different at impacted sites: in both corals the main symbiotic taxon decreased in abundance. In contrast, opportunistic bacterial families, such as e.g. Vibrionaceae and Rhodobacteraceae, were more abundant in corals at impacted sites. In conclusion, microbial community response revealed a measurable footprint of anthropogenic impacts to coral ecosystems close to Jeddah, even though the corals appeared visually healthy.

The fine particles (PM2.5) were collected for 24 h from Agra atmosphere and chemically characterized during the one year study period. The average concentration of PM2.5 was 90.21 ± 20.62 μg m−3 which is higher than NAAQS and WHO annual standards and their seasonal trend was winter > summer > monsoon. Ionic study indicates that cations were dominant in comparison to anions. Seasonally, F−, Ca2+ and Mg2+ were higher during summer period and Cl−, NO3−, NH4+ and K+ were higher during monsoon period while SO42− was higher during winter season. The ratios Ca2+/Na+, Mg2+/Na+ and SO42−/Na+ were higher, while Cl−/Na ratio was lower than sea water ratio indicating the incorporation of non marine constituents in aerosols. The observed Cl−/Na+ (average 0.71) deviate considerable from the Sea water ratio suggesting either a fractionation of Cl− or enrichment of Na+ as there was significant deviation from marine sources. Linear correlation was observable between nss-Ca2+ and nss-Mg2+ with HCO3− throughout the annual seasonal cycle (HCO3−: Ca = 0.59, HCO3−: Mg2+ = 0.53) suggesting the origination of these species from soil dust. The calculated conversion ratio of ‘S’ (CRS) was lower than ‘N’ (CRN) which suggests that the secondary formation of NO3− aerosol from NO2 was more predominant than SO42−. Trajectory analysis indicates that long range transportation also contributes to PM2.5 mass over the measurement site.

The sources, distribution, surface features, polymer composition and age of microplastic pellets (MPPs) in surface sediments along the Chennai coast during March 2015 (pre-Chennai flood) and November 2015 (post-Chennai flood) were characterised using a Stereoscopic microscope and FTIR-ATR spectroscopy. White MPPs were the most abundant, and specifically polyethylene (PE) and polypropylene (PP) were the dominant polymer types of MPPs found on the coast during both the times. The abundance of MPPs in November 2015 was three-fold higher than those found in March 2015, confirming that huge quantity of fresh MPPs washed through Cooum and Adyar rivers from land during the flood. The winds and surface currents during November were the driving forces for the transportation and deposition of MPPs from the sea to beaches. The results of this study will be useful to formulate beach MPPs litter management policies to effectively create long-term solutions.

Concentrations of total mercury (THg) were measured in coastal marine sediments near a former chlor-alkali plant in Chaleur Bay, New Brunswick. The chlor-alkali plant has been a local point source of THg since operation began in 1963. Historical THg contamination of marine sediments and biota has been widely reported. No baseline assessment has been conducted following plant closure in 2008. Surface (0–2cm) oxidized marine sediments were sampled along a single 5.2km transect radiating from the former plant and analysed for THg. THg concentrations ranged from 0.04–0.28μgg−1. Some localised THg concentrations exceeded Canadian marine sediment quality guidelines (n=4), but all samples (n=14) were significantly lower than previous studies conducted during plant operation. Plant closure (source control) and natural sediment recovery likely responsible for attenuating THg concentrations, but burial in deeper anoxic sediments may increase bioavilability of Hg that could pose ecological risks to marine biota.

The present field study aimed to determine the extent of pollution in the Red Sea coast of Yemen Republic using a battery of biomarkers in sea catfish, Arius thalassinus, originating from a reference site in comparison with a polluted site. We reported the concentration of heavy metals in some vital fish organs and their effects on the morphological, hematological, biochemical and oxidative stress biomarkers accompanied by the examination of histopathological alterations. The obtained results showed clear signs of stress in fish from a polluted site. Linear correlation analysis exhibited that the biomarkers response could be linked to the detected metals bioaccumulation. In addition, principal component analysis showed a clear separation of sampling sites in two different assemblages. Semi-quantitative analysis for the observed histopathological lesions revealed that gills were the most affected organs with signs of severe alterations. This field investigation provides a baseline data on pollution status in this region.

In this study, positive matrix factorization models (PMFx) were used to analyze the sources of sedimentary PAHs in Yangtze River Estuary (YRE) using 120 data samples from 30 sites collected over four seasons. Three sources were defined for the PAHs: coal and gasoline combustion was the dominant source, accounting for approximately 50%; coke plant emissions and wood or grass combustion each contributed approximately 25%. The coal tar origin was the major source in summer; wood or grass combustion dominated in autumn; coal combustion was the primary source of PAHs in spring and winter. More than 90% of the coke plant emissions were from summer, while pollutants from wood or grass combustion were discharged primarily in autumn. These three sources distributed in different primary regions, the spatial patterns of coal combustion presented an increasing trend in the seaward direction.

Acid Leachable Trace Metal (ALTMs) concentrations in tourist beaches of Richards Bay, Kwazulu-Natal, South Africa were assessed. 53 surface sediment samples were collected from five different beaches (Kwambonambi Long Beach; Nhlabane Beach; Five Mile Beach; Alkanstrand Beach and Port Durnford Beach). The results of ALTMs (Fe, Mn, Cr, Cu, Ni, Co, Pb, Cd, Zn, As, Hg) suggest that they are enriched naturally and with some local industrial sources for (avg. in μgg−1) Fe (3530–7219), Mn (46–107.11), Cd (0.43–1.00) and Zn (48–103.98). Statistical results indicate that metal concentrations were from natural origin attributed to leaching, weathering process and industrial sources. Comparative studies of metal concentrations with sediment quality guidelines and ecotoxicological values indicate that there is no adverse biological effect. Enrichment factor and geoaccumulation indices results indicate moderate enhancement of Fe (Igeo class 1 in FMB), Cd (EF>50; Igeo classes 2–4) and Zn (Igeo classes 1 & 2).

Exposure to ambient (urban) air pollution consisting of fine particles is linked with the increased risk of respiratory as well as cardiovascular diseases and cancers. Recent studies have, however, suggested the adverse effects of PM₂.₅ and especially ultrafine particulate matter (UFPM or PM₀.₁: size <0.1 μm or 100 nm) in ambient air pollution in the brain and central nervous system (CNS). These particles can travel beyond the pulmonary systems to the CNS and, ultimately, reach the brain that may cause neurological diseases including Alzheimer’s disease, Parkinson’s disease, and other forms of dementia. The polychlorinated biphenyls (PCBs) can also be linked to neurological disorders identically. An attempt has been made in this article to make an assessment on the roles of UFPM and PM₂.₅ as well as PCBs on the neurological disorders from exposure to ambient air pollution. Finally, several recommendations are made for future scope of research followed by regulatory enforcement strategies to reduce the occurrence of neurological disorders from exposures of ambient air pollution to humans.

Once non-biodegradable, microplastics remain on the environment absorbing toxic hydrophobic compounds making them a risk to biodiversity when ingested or filtered by organisms and entering in the food chain. To evaluate the potential of the contamination by microplastics in mussels cultivated in Jurujuba Cove, Niterói, RJ, waters of three stations were collected during a rain and dry seasons using a plankton net and later filtered. Microplastics were quantified and characterized morphologically and chemically. The results showed a high concentration of microplastics in both seasons with diversity of colors, types and sizes. Synthetic polymers were present in all samples. The presence of microplastics was probably due to a high and constant load of effluent that this area receives and to the mussel farming activity that use many plastic materials. Areas with high concentrations of microplastics could not be used for mussel cultivation due to the risk of contamination to consumers.