Comparative studies were developed with regard to the criteria emissions of THC - total hydrocarbons, CO - carbon monoxide and NOx - nitrogen oxides, and BTEX (benzene, toluene, ethyl benzene and xylenes). Three four-stroke motorcycles were fuelled with E22 fuel (gasoline with 22% of ethanol). One flex fuel motorcycle was also fuelled with E100, 100% Hydrated Reference Ethanol, and with E61 (61% of ethanol). Criteria emissions were quantified using traditional measurement techniques based on the European Directive 97/24/EC (EURO protocol). To determine the BTEX emissions, gas chromatography coupled with mass spectrometry was employed. All motorcycles were equipped with a catalyst (TWC) used to reduce the amount of toxic emissions in the exhaust gases. To evaluate the performance of the catalyst, one motorcycle was tested with and without the device. One motorcycle was tested according to two different test protocols, namely, the ECE/TRANS/180 WMTC, also known as the Worldwide Motorcycle Test Cycle, and the EURO protocol. The main results were that toluene emissions were more prevalent than other aromatics. The tests with and without the catalyst showed that after the catalyst was employed the conversion efficiencies for benzene, toluene, ethyl benzene and xylene were 52.3%, 84.0%, 85.0%, and 86.0%, respectively. The results regarding the flex fuel motorcycle show that BTEX emissions decrease with an increase of ethanol in the mixture. Comparing the EURO and WMTC protocols, it was observed that the WMTC protocol generates lower emissions compared to the EURO protocol; however, NOx showed the opposite trend of BTEX.

Spatial and temporal patterns of coastal microbial pollution are not well documented. Our study examined these patterns through measurements of fecal indicator bacteria (FIB), nutrients, and physiochemical parameters in Hilo Bay, Hawai'i, during high and low river flow. >40% of samples tested positive for the human-associated Bacteroides marker, with highest percentages near rivers. Other FIB were also higher near rivers, but only Clostridium perfringens concentrations were related to discharge. During storms, FIB concentrations were three times to an order of magnitude higher, and increased with decreasing salinity and water temperature, and increasing turbidity. These relationships and high spatial resolution data for these parameters were used to create Enterococcus spp. and C. perfringens maps that predicted exceedances with 64% and 95% accuracy, respectively. Mapping microbial pollution patterns and predicting exceedances is a valuable tool that can improve water quality monitoring and aid in visualizing FIB hotspots for management actions.

Marine seismic surveys produce high intensity, low-frequency impulsive sounds at regular intervals, with most sound produced between 10 and 300Hz. Offshore seismic surveys have long been considered to be disruptive to fisheries, but there are few ecological studies that target commercially important species, particularly invertebrates. This review aims to summarise scientific studies investigating the impacts of low-frequency sound on marine fish and invertebrates, as well as to critically evaluate how such studies may apply to field populations exposed to seismic operations. We focus on marine seismic surveys due to their associated unique sound properties (i.e. acute, low-frequency, mobile source locations), as well as fish and invertebrates due to the commercial value of many species in these groups. The main challenges of seismic impact research are the translation of laboratory results to field populations over a range of sound exposure scenarios and the lack of sound exposure standardisation which hinders the identification of response thresholds. An integrated multidisciplinary approach to manipulative and in situ studies is the most effective way to establish impact thresholds in the context of realistic exposure levels, but if that is not practical the limitations of each approach must be carefully considered.

This study investigated the contents of Cu, Zn and Pb in seawater, sediment, different shell sizes of mussel (Mytilus galloprovincialis) and sea snail (Rapana venosa) samples collected from four different provinces of the Eastern Black Sea Region. With the exception of Zn, all the metal concentration values measured in the sea snail were observed to be higher than those of mussels in all stations. While the correlation between mussels and sea snail according to metal concentrations was found to be positive (p˂0.05), this relation was not observed between the other parameters, such as the shell sizes, salinity and pH (p˃0.05). Although the mean concentration values of Cu, Zn, and Pb for mussel and sea snail are significantly above the tolerable levels, the estimated daily intake values for mussel were below the daily intake recommended.

Being the most reactive of all chemical elements and the lightest member of halogen group, fluorine is found in the environment as fluoride. Both natural and anthropogenic activities are responsible for fluoride contamination in groundwater. Fluoride has dual effect on human health. While lower concentration (<0.5 mg/L) is responsible for dental fluorosis, higher concentration (>1.5 mg/L) leads to skeletal fluorosis and even death. The present review paper is aimed at providing detailed occurrence of fluoride pollution around the globe and in India. Among the different defluoridation techniques to remove excess fluoride from contaminated drinking water at both community and domestic levels, adsorption is found to be very effective due to its technical feasibility, simple characteristics and comparative low-cost nature. Various adsorbents have been tested for their ability to treat fluoride contaminated water, viz., activated carbon, activated alumina, soil, clay and a variety of waste materials. Since fluoride pollution of drinking water is a major concern of poor people as they cannot afford to spend on purification of water, usage of low-cost natural mineral (natural mineral) as adsorbent for fluoride removal is one of the most essential issues in modern era. The present review bestows a detailed discussion on natural mineral as adsorbent used in defluoridation process with special emphasis on soil and low-cost clay minerals.

This study focused on whistles produced by Guiana dolphin under different noise conditions in Guanabara Bay, southeastern Brazil. Recording sessions were performed with a fully calibrated recording system. Whistles and underwater noise levels registered during two behavioral states were compared separately between two areas. Noise levels differed between the two areas across all frequencies. Whistle duration differed between areas and was negatively correlated with noise levels. Whistling rate was positively correlated with noise levels, showing that whistling rate was higher in noisier conditions. Results demonstrated that underwater noise influenced Guiana dolphin acoustic behavior.

This study aims at describing and interpreting concentrations of arsenic (As), mercury (Hg) and vanadium (V) in seven species of fish, three species of shellfish, one species of crab and two species of shrimp from the typical estuary-bay ecosystem. Arsenic, Hg and V differed among species, and the highest As, Hg and V were observed in shellfish. The stable nitrogen (δ15N) and carbon (δ13C) isotopes were determined to investigate the trophic interactions between fluctuating environment and aquatic species. Arsenic concentrations in samples were found negatively correlated with δ15N, implying biodilution effect of As through the food web, while Hg concentrations in samples were positively correlated with δ15N, indicating their biomagnification effect. The estimated daily intake values of Hg and V in this study were all below the oral reference dose. However, elevated As intakes of some aquatic organisms suggested a potential risk for frequent consumers.

Hydrostatic pressure (HP) increases linearly with depth in aquatic environments, so that many fish species routinely experience moderate-to-high HP levels (i.e., from a few to dozens of MPa). Biological effects of this thermodynamic variable are evidenced by a reduced functionality of many biomolecular systems, even in barotolerant and barophilic species. It is likely that environmentally-relevant HP levels (i.e., above atmospheric) could also modulate the responsiveness to and toxic effects of pollutants in fish. Still, only a few laboratories have investigated this possibility. The already-published ecobarotoxicological studies have brought strong support to the notion that HP can indeed modulate pollutant response in shallow-water and deep-sea animals. A careful reassessment of toxicity responses is therefore required. To quantify the exact influence of HP in marine fish toxicology, a research framework is proposed that should ensure the collection of meaningful data for risk assessment, using standard toxicity testing and mechanistic approaches.

The direct effect of atmospheric turbulence on plume rise in the current research work is studied through examining the turbulence intensity parameter. A hybrid unsteady Reynolds averaged Navier Stokes (RANS) and large eddy simulation (LES) numerical approach is applied with a new mixed scale sub-grid parameterization technique in the commercial ANSYS Fluent software in order to simulate the buoyant plume behavior in a turbulent crossflow. The accuracy of the simulation method is crosschecked against the wind tunnel data available in the literature. The numerical simulation results in various operating conditions are used to derive a new plume rise formula in which the direct effect of atmospheric turbulence intensity at stack height (IAir) is explicitly introduced in the plume rise formula. Furthermore, the buoyancy parameter of the flue gas is determined at some distances upstream of the stack top surface to include the whole effects of source buoyancy on the plume rise. The value of IAir at stack height is obtained by measuring the standard deviation of wind velocity at stack height. The sensitivity analysis showed that by increasing the atmospheric turbulence intensity, the final plume rise decreases because of the updraft and downdraft motions of turbulence and it has been found that there is a linear dependency between the plume rise and (IAir)−1.22. The quantile-quantile plots show that the new model can predict the simulated plume rise with a deviation factor of 1.0025 whereas the conventional models overestimate the final plume rise at least by a factor of 2.2.