International audience | Gallic and pelargonic acids are naturally found in a variety of plants and food products. Despite their extensive use in man-made applications, little is known regarding their potential risks to aquatic vertebrates. The aim of this work was to assess the acute toxicity of these polyphenolic and fatty acid compounds to the zebrafish. In order to get insights into sublethal effects, the enzyme activity of usual biomarkers related to oxidative stress and biotransformation were also assessed in fish. These latter included total superoxide dismutase, catalase as well as total glutathione peroxidase for antioxidant defence mechanisms and glutathione S-transferase for biotransformation related enzyme. Gallic acid was practically non-toxic (96-h lethal concentration (LC50) > 100 mg/L) whereas pelargonic acid was slightly toxic (96-h LC50 of 81.2 mg/L). Moreover, biomarker analyses indicated enhanced superoxide dismutase activity in fish exposed to 20, 40 and 100 mg/L of gallic acid compared to control. A dose-dependent induction of glutathione peroxidase and glutathione S-transferase was reported following gallic acid exposure at the tested concentrations of 10, 20 and 40 mg/L, with the exception of 100 mg/L of substance where basal activity levels were reported. In the case of pelargonic acid, there was no change in antioxidant enzyme activity while an inhibition of glutathione S-transferase was observed from organisms exposed to 45, 58 and 76 mg/L of test solution. The results concerning sublethal effects on biological parameters of zebrafish highlighted thereby the need for further investigations following chronic exposure to both organic acids.

This study presents a model to assess the oil spill risk in Garorim Bay in Korea, where large-scale oil spill accidents frequently occur. The oil spill risk assessment is carried out by using two factors: 1) The impact probability of the oil spill, and 2) the first impact time of the oil that has been spilt. The risk assessment is conducted for environmentally sensitive areas, such as the coastline and aquaculture farms in the Garorim Bay area. Finally, Garorim Bay is divided into six subareas, and the risks of each subarea are compared with one another to identify the subarea that is most vulnerable to an oil spill accident. These results represent an objective and comprehensive oil spill risk level for a specific region. The prediction of the oil spill spread is based on real-time sea conditions and can be improved by integrating our results, especially when sea conditions are rapidly changing.

Fine particulate matter samples (PM2.5) were collected from three locations around the Denver–Metropolitan area to study the impacts of the ground–level light rail on airborne metal concentrations. Size–segregated PM was collected on board the trains, at the side of the tracks, and at a background location in downtown Denver. Results from this study showed highest crustal enrichment factors of metals in samples collected on board the train, despite lower concentrations of total PM2.5. Metals commonly found in steel such as Fe, Cr, Mn, and Ni, all exhibited elevated concentrations relating to train activity over the background site. Iron in the PM2.5 at track–side and on board the trains was above the background by a factor of 1.89 and 1.54, respectively. For Mn, the ratios were 1.34 for the track–side and 0.94 for the on board samples. Cr and Ni exhibited higher ratios over the background only in samples collected on board the trains at 1.59 (Cr) and 1.26 (Ni). Soluble metals were measured with Ni (53–71%), Cu (52–81%), and Zn (30–81%) exhibiting the highest solubilities across the different sites. Soluble Fe ranged from 8–15% for the total measured Fe, indicating a non–crustal source of Fe. Soluble Fe was also characterized as Fe(II) and Fe(III) with 87–90% of the soluble Fe being Fe(II), similar to results from studies in Los Angeles, CA and East St. Louis, IL but higher than in Atlanta, GA and Waukesha, WI.

In this paper, we studied the regional aerosol and air quality over an urban location, Pune, India during the period from 8 to 18 November 2012, encompassing a major Indian celebration, namely, Diwali Festival (12–14 November 2012) and also a clean (control) day (9 November 2012). A suit of ground–based measurements, employing solar radiometers (Microtops II and Cimel Sun–sky radiometer), Nephelometer, and satellite observations carried out over the study region have been applied for these investigations. The study revealed many interesting results which include (i) almost four–fold enhancement in AOD and fine mode dominated aerosol size distribution (ASD) during Diwali compared to clean day conditions; (ii) higher columnar water vapor (H2O), nitrogen dioxide (NO2), and lower ozone (O3) during Diwali period; (iii) higher cooling at bottom (–117W m−2) and top of the atmosphere (–33W m−2) and warming (+82W m−2) in the atmosphere during the festival period, (iv) abundance of fine mode anthropogenic scattering particles associated with greater real part and smaller imaginary part of refractive index, and higher single scattering albedo, (v) higher backscattering coefficient revealing intrusion of more aerosol particles, higher depolarization ratio indicating particles of non–spherical nature, presence of water–phase particles, more polluted smoke and dust particles, (vi) greater attenuation and poor horizontal/vertical visibility, and (vii) dominance of urban industrial/biomass burning aerosols among other aerosol types. These results have been compared with concurrent satellite products and found to be consistent. The results have been further explained with local meteorology, back–trajectory analysis and satellite rapid response images.

The nutrient uptake and release by the mussels in relation with amount of food consumption are emphasised in this research. Results of the study demonstrate that about 16% of the total mass dry weight food consumed by the mussels was released as faeces. The depositions of particulate carbon, nitrogen, and phosphorus in mussel faeces were found to be 26.3, 5.7, and 0.6mg/day/indv respectively. Soluble inorganic nutrients such as NH4+-N (2.5mg/day/indv), and PO43−-P (0.6mg/day/indv) were also released as mussel excretion. The nutrient absorption efficiency for the green mussel body was found to be 65.1% for carbon, 62.1% for nitrogen, and 79.2% for phosphorus. Subsequently, green mussels can remove particulate carbon, nitrogen and phosphorus at 108.1, 13.5, and 4.6mg/day/indv from aquatic systems. Finally, the results can help in estimating the carrying capacity of mussel cultivation without deteriorating the water quality in marine ecosystems.

Development of human activities in the Klaipėda strait generates a wide spectrum of underwater noise. In the fall of 2013, at the liquid natural gas terminal construction site in the shallow Curonian Lagoon area, an assessment of possible negative impacts on migrating salmon fish caused by pile driving noise was made. It is well known that impact hammer pile driving generates pulses with extremely high underwater noise levels. The obtained results proved that the pile hammering into the lagoon bottom generated pulses with a sound exposure level of 218dB re 1μPa2s @1m thus posing a risk to the migrating fish.

To control algae bloom and eutrophication in the tropical semi-closed harbor of the Hongsha Bay in Sanya, China, polyculture systems with macroalgae Eucheuma gelatinae and bivalves Gafrarium tumidum were studied. First, nine polyculture combinations with E. gelatinae and G. tumidum were selected in a pool. Two combinations were then chosen by response surface analysis and used for further study to validate their effect on controlling the microalgae density and reducing the nutrition concentration in the pool. Subsequently, the two selected combinations were used to study the effect on the purification of eutrophic seawater and control of algae bloom in a sea mesocosm. The results indicated that polyculture with E. gelatinae and G. tumidum enhanced the purification of eutrophic seawater and control of algae bloom. These two polyculture combinations are considered suitable for the Hongsha Bay of Sanya in China. The two combinations present an excellent effect on controlling the microalgae density and reducing the nutrition concentration.

A prediction that faunal recovery of a marine aggregate extraction site subjected to high dredging intensity was likely to take 15–20years was investigated. Samples were collected at the high dredging intensity site and two reference sites in 2011 (15years post-dredging). Results indicated that the high site had similar sediment characteristics to the reference sites by 2011. Macrofaunal data analyses showed no difference between the values of all calculated univariate measures (abundance, number of taxa, biomass and evenness) between the high and reference sites. Multivariate analyses found that the macrofaunal community at the high site was comparable to those of the reference sites by 2011. Overall, the results supported the predicted recovery time. The findings of the study suggest that persistent physical impacts prolonged the biological recovery of the high site.

Ambient fine particulate matter (PM2.5) pollution is currently a major public health concern in Chinese urban areas. However, assessment of ambient PM2.5 exposure and its health effects is challenging in China because the exposure primarily occurs indoors. There is large inter-home variability of the fraction of ambient PM2.5 that penetrates indoors and remains airborne (Finf), and the factors influencing this variability are unknown. In this study, 24-h real-time indoor and outdoor PM2.5 mass concentrations were concurrently collected for 41 urban residences in the non-heating season. The Finf were estimated with steady-state and dynamic models derived from mass balance considerations. Multivariate statistical analyses were employed to examine the associations between Finf and 78 factors related to building characteristics, motor vehicle traffic, human behavior, meteorology, furnishings, and atmospheric/indoor chemistry. The estimate of Finf over the 24-h monitoring period with the steady-state model was 0.72 ± 0.01; the Finf estimate for single residences, using the dynamic model, were 0.59 ± 0.13 (N = 33). Two predictive models for Finf were constructed with categorical and numerical variables, respectively. The results revealed that building characteristics, traffic, wall and floor coverings, and human behavior had substantial influence on Finf in the non-heating season. The variance contributions of the determinants of traffic, wall and floor coverings, and human behavior were comparable to or even greater than those of the building characteristics.