California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, México, than in California, USA

Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, México, January 2000-November 2001. Summation operatorDDTs were the dominant group (geometric mean 3.8 microg/g lipid weight), followed by polychlorinated biphenyls ( summation operatorPCBs, 2.96 microg/g), chlordanes (0.12 microg/g) and hexachlorocyclohexanes (0.06 microg/g). The summation operatorDDTs/ summation operatorPCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north.     

Results and evaluation of the first study of organochlorine contaminants (PCDDs, PCDFs, PCBs and DDTs), heavy metals and metalloids in birds from Baja California, México

Organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p-p'-DDE), heavy metals (Pb, Cd, Zn, Cu), and arsenic were measured in house sparrows (Passer domesticus) and common ground doves (Columbina passerina) from Baja California Sur, México. Concentrations of PCDD/Fs were low, with 21 pg/g for house sparrows, and 7.7 pg/g for common ground doves. Non-ortho-PCB concentrations in house sparrow and common ground doves were 58 and 254 pg/g, respectively, and are within the highest concentrations reported in species that are in the low levels of food webs. The major differences in organochlorine levels between species were found for ortho-PCBs and DDTs. ortho-PCB levels were higher in the seedeater species, whereas DDT levels were higher in the omnivorous species. Heavy metal levels were far below those associated with negative effects.     

Inflammation biomarkers associated with arsenic exposure by drinking water and respiratory outcomes in indigenous children from three Yaqui villages in southern Sonora,México

Environmental Science and Pollution Research - Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and...     

Titanium dioxide and graphitic carbon nitride–based nanocomposites and nanofibres for the degradation of organic pollutants in water: a review

Environmental Science and Pollution Research - The paper reviews graphitic carbon nitride–based nanostructured photocatalytic materials and nanofibres for applications in water purification....     

Understanding the patterns and processes underlying water quality and pollution risk in West–Africa River using self-organizing maps and multivariate analyses

Environmental Science and Pollution Research - Rivers are dynamic systems in complex interactions with their surrounding environments. Reliable and fast interpretation of water quality is therefore...     

Recharge and Flow in the Medicine Lake Volcano–Fall River Springs Groundwater Basin,California

Isotopic measurements of the 34 m³/s discharge from the Fall River Springs of northern California indicate recharge from 50 km upgradient in high elevation regions of Medicine Lake Volcano. Age determinations suggest less than 20-year travel time. Data demonstrate Klamath Basin further north cannot be a recharge source. Mass balance calculations support that annual precipitation on the volcano supplies observed spring discharge, requiring 50%–75% recharge rates. Radiocarbon and δ¹³C of dissolved inorganic carbon indicate 30%–40% is derived from magmatic CO₂. Measured excess ³He is also consistent with the presence of magmatic gas derived from the Quaternary Age Medicine Lake Volcano.     

Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juárez, Chihuahua (México)

Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO₂) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO₂ appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children’s exposures to these pollutants vary based on the location of their school.     

How to stay together? Habitat use by three sympatric sharks in the western coast of Baja California Sur,Mexico

Environmental Science and Pollution Research - Sharks are top predators and play an important role in the regulation of marine ecosystems at lower trophic position. Mustelus californicus, Sphyrna...     

Periphyton as an indicator of water quality in the St Lawrence River (Québec, Canada)

The performance of various algal indices to document improvements in water quality across a low nutrient concentration gradient was assessed during 2 years in the St Lawrence River (Quebec, Canada). Water-quality variables and periphyton samples were collected on navigational buoys near Montreal during the spring, summer and fall of 1994 and 1995. Exposure to urban wastewater varied widely within the sector surrounding the island of Montreal, with some areas upstream receiving no direct effluents and areas further downstream receiving treated and untreated wastewater. Faecal coliform concentrations provided a good tracer of effluents and were significantly correlated to nutrient concentrations (r = 0.33-0.72, p < 0.001) and water transparency (r = 0.70, p < 0.001). Despite a strong gradient in faecal coliform concentration (< 2 to > 20 000 UFC/100 ml), algal biomass and diversity did not reflect differences between sites with varying levels of urban wastewater. Taxonomic composition of periphyton communities, particularly the presence of the cyanophyte Plectonema notatum Schmidle, was related (r = 0.48, p = 0.004) to exposure to urban effluents. Variables describing seasonal changes (temperature, Julian day, river discharge, conductivity, NO2-NO3) explained a large fraction of total variance (38-52% of total variance) and thus exerted the predominant influence on algal biomass and species composition in the St Lawrence River. Variables describing the presence of effluents explained 1-22% of the variance in compositional data. Subtle changes in periphyton species composition were the only response to different levels of exposure to urban wastewater in the Montreal area, which represented relatively small differences in comparison to natural seasonal variability.     

Characteristics of dissolved organic matter in surface water and sediment and its ecological indication in a typical mining-affected river—Le’an River,China

Environmental Science and Pollution Research - Dissolved organic matter (DOM) plays an important role in the cycling and toxicity of heavy metals in aquatic systems. However, most studies have...     

Characterization of atmospheric aerosols by SEM in a rural area in the western part of México and its relation with different pollution sources

Samples of particulate matter were collected during the period from October 2006 through September 2007 in a rural station located 12 km from the city of Colima. A total of 3600 particles were analyzed by SEM-EDS and then classified by their chemical composition and morphology in order of abundance: those rich in C, Fe, Si–Al, Cl–Na, Ca, Ba; and to a lesser abundance, particles rich in heavy metals such as Pb and V–Ni were observed. A factorial analysis was carried out to determine the main elements related with the emission sources such as crustal/farming; fuel-oil; marine; volcanic activity and industry. Trough the seasons, the dominant winds causes the presence of anthropogenic particles in the rural site. The information presented in this study aims to give insight and detailed of the analysis of the morphological characteristics and chemical composition of atmospheric particles at individual level in a rural site from Colima State, Mexico.     

Correction to: Characteristics and distribution of microplastics in shoreline sediments of the Yangtze River,main tributaries and lakes in China—From upper reaches to the estuary

Environmental Science and Pollution Research -     

Evaluation of disinfection techniques in the treatment of advanced primary treated wastewater for Ciudad Juárez, México.

The purpose of this study was to develop and evaluate the effectiveness of alternative disinfection techniques at the bench-scale level using wastewater from Ciudad Juarez, Mexico, as model feed. This paper presents findings on the effectiveness of UV radiation, peracetic acid (PAA), chlorine dioxide (ClO2), and hypochlorous acid (HOCl) as disinfectants for advanced primary treatment (APT) plant effluent. Wastewater samples for bench-scale testing were collected from an agua negra ("black water") ditch that is part of the combined sewer system in Ciudad Juarez. Bench-scale simulations of the APT process used in Ciudad Juarez were run using a jar test apparatus and aluminum sulfate [Al2(SO4)3] as the coagulant. Jar test effluent from the bench system was used for disinfection testing. The Mexican discharge quality standard for total coliforms is 10 000/100 mL. Ultraviolet radiation met this standard at a dose of 47.5 mW-s/cm2. Ultraviolet disinfection proved reliable and effective despite the presence of suspended solids, and UV dose effectiveness expressed as a total coliforms survival ratio was best explained by a linear regression model. The ClO2 dose ranged from 10 to 20 mg/L and was only effective under ambient temperature conditions found during the winter months; PAA disinfection never met Mexican standards. Chlorine disinfection was effective at a dose range of 8 to 10 mg/L on samples collected at low temperature conditions. Since the completion of this research, Ciudad Juarez has discontinued the use of chlorine disinfection because of its high cost and ineffectiveness.     

The deep-sea as a final global sink of semivolatile persistent organic pollutants? Part I: PCBs in surface and deep-sea dwelling fish of the north and south Atlantic and the Monterey Bay Canyon (California)

The understanding of the global environmental multiphase distribution of persistent organic pollutants (POPs) as a result of the physico-chemical properties of the respective compounds is well established. We have analysed the results of a vertical transport of POPs from upper water layers (0-200 m) to the deepwater region (> 800 m) in terms of the contamination of the biophase in both water layers. The contents of persistent organochlorine compounds like polychlorinated biphenyls (PCBs) in fish living in the upper water layers of the North Atlantic and the South Atlantic, and at the continental shelf of California (Marine Sanctuary Monterey Bay and its deep-sea Canyon) are compared to the levels in deep-sea or bottom dwelling fish within the same geographic area. The deep-sea biota show significantly higher burdens as compared to surface-living species of the same region. There are also indications for recycling processes of POPs--in this case the PCBs--in the biophase of the abyss as well. It can be concluded that the bio- and geo phase of the deep-sea may act similarly as the upper horizons of forest and grasslands on the continents as an ultimate global sink for POPs in the marine environment.     

Characteristics and distribution of microplastics in shoreline sediments of the Yangtze River,main tributaries and lakes in China—From upper reaches to the estuary

Environmental Science and Pollution Research - Microplastics (MPs) pervade the environment and increasingly threaten both natural ecosystems and human health. In this study, we investigated MP...     

The deep-sea as a final global sink of semivolatile persistent organic pollutants? Part II: Organochlorine pesticides in surface and deep-sea dwelling fish of the north and south Atlantic and the Monterey Bay Canyon (California)

The understanding of the global environmental multiphase distribution of persistent organic pollutants (POPs) as a result of the physico-chemical properties of the respective compounds is well established. We have analysed the results of a vertical transport of POPs from surface water to deepwater in terms of the contamination of the biota living in the respective environmental compartments. Samples were taken from the North and the South Atlantic and from the uprising water region of the continental shelf of California (Marine Sanctuary Monterey Bay and its Canyon). The contents of persistent organochlorine pesticides (DDTs, chlordanes, toxaphenes, HCHs, and HCB) in surface-living fish are compared to those in deepwater fish of the same geographic area. The deepwater biota show significantly higher burdens as compared to surface-living species of the same region. There are also indications for recycling processes of POPs of the class of organochlorine pesticides in the biophase of the abyss as well. It can be concluded that the bio- and geophase of the deep-sea may act as an ultimate global sink for persistent semivolatile contaminants in the marine environment like the soil on the continents.     

NMOC,ozone, and organic aerosol in the southeastern United States, 1999–2007: 2. Ozone trends and sensitivity to NMOC emissions in Atlanta,Georgia

Non-methane organic carbon (NMOC) measurements made in Atlanta, Georgia from 1999–2007 are used with nitrogen oxide (NO_x or NO_y) and ozone (O₃) data to investigate relationships between O₃ precursors and peak 8-hour O₃ concentrations in the city. Data from a WNW-to-ENE transect of sites illustrate that the mean urban peak 8-hour O₃ excess constitutes about 20% of the peak 8-hour O₃ measured at the area-wide maximum O₃ site when air-mass movement is from the northwest quadrant; local influence is potentially greater on days with more stagnation or recirculation. The peak 8-hour O₃ concentrations in Atlanta increase as (1) surface temperature (T), ambient NMOC and NO_y concentrations, and previous-day peak O₃ concentrations increase, and as (2) relative humidity, surface wind speeds, and ratios of NMOC-to-NO_y decrease. An observation-based statistical model is introduced to relate area-wide peak 8-hour O₃ concentrations to ambient NMOC and NO_y concentrations, while accounting for the non-linear dependences of peak 8-hour O₃ concentrations on meteorological factors. On the majority of days when the area-wide peak 8-hour O₃ exceeds 75 ppbv, meteorologically-adjusted peak 8-hour O₃ concentrations increase as ambient NMOC concentrations increase (NMOC sensitive) and ambient NO_y concentrations decrease. This result contrasts with regional conditions in which O₃ formation appears to be NO_x-sensitive in character. The results offer observationally-based information of relevance to O₃ management strategies in the Atlanta area, potentially contributing to “weight-of-evidence” assessments.     

Biomarker responses in European eel (Anguilla anguilla) exposed to persistent organic pollutants. A field study in the Vaccarès lagoon (Camargue, France)

A screening of relevant biomarkers was carried out in order to evaluate metabolic and cellular damages in European eels exposed to a non-point source contamination by persistent organic pollutants (POP) such as polycyclic aromatic hydrocarbons (PAH) and organochlorine compounds (OC) in a protected area, the Nature Reserve of Camargue (France). Investigations were focused on metabolic responses including detoxification mechanisms (biotransformation, antioxidant process), energy requirements and enzymatic membrane markers either involved in neuronal conduction (acetylcholinesterase, AChE) or in osmoregulation and energy metabolism (ATPases). The hepatic and muscular glycogen rates seemed to be suitable biomarkers as well as three hepatic activities involved in the protection against oxyradicals: catalase, glutathione peroxidase (SeGPx) and superoxide dismutases (SOD). The muscle and gill ATPases as well as the muscle and brain AChE showed more significant relevance in terms of biomarkers than the biotransformation enzymes: ethoxyresorufine-O-deethylase (EROD) and uridine diphospho-glucuronyl transferase (UDPGT). However, most of these enzymatic activities depend on numerous abiotic factors, which must be taken into account in such a biomarker assessment approach. Our study provides some conclusive elements to approve the use in situ of biomarkers developed from laboratory studies. It also raises a question regarding the location of contaminant impregnation in fish organ, in relation with age, development status or mode of contamination, and its influence on biomarker response. If the relevance of membrane indicators is confirmed, this study provides an original statement of the extent of the ecotoxicological threat for the aquatic species in a protected area, due to the occurrence of POP in the cell membranes.     

The assessment of water quality in the Lower Luján River (Buenos Aires,Argentina): phytoplankton and algal bioassays

The monitoring of river phytoplankton and several hydrological, physical and chemical variables, in combination with bioassays using Selenastrum capricornutum Printz, allowed the characterisation of three distinct reaches of the Lower River Luján. The upstream stretch, characterised by the lowest depth and discharge, registered the highest nutrient, dissolved heavy metal and chlorophyll a concentrations in accordance with low phytoplankton diversity and the occurrence of several species typical of organically polluted lowland rivers. A downstream improvement, concomitant to increasing river discharge, is revealed by a progressive decrease of organic pollution parameters even though algal toxicity is registered through bioassays. The water input from the Parana River through the G. Arias Channel plays an important role in the regulation of the limnology of the Lower Luján River. As a result of marked increasing discharge, depth and width, there is a decrease in nutrient concentration and phytoplankton density and an increase in dissolved oxygen concentration. Likewise, algal growth rates in the bioassays showed less toxic effect.     

Characteristics of lead geochemistry and the mobility of Pb isotopes in the system of pedogenic rock–pedosphere–irrigated riverwater–cereal–atmosphere from the Yangtze River delta region,China

Knowledge of the characteristics of Pb and its isotopic transfer in different compartments is scant, especially for the mobility of Pb isotopes in the geochemical cycle. The present study characterizes differential Pb transport mechanism and the mobility of Pb isotopes in the pedogenic parent rock–pedosphere–irrigated riverwater–cereal–atmosphere system in the Yangtze River delta region, by determining Pb concentration and Pb isotopic ratios of pedogenic parent rocks, fluvial suspended particle matter, tillage soils, soil profiles, irrigated riverwater, fertilizer, Pb ore, cereal roots and grains. The results show that Pb isotopes in the geochemical cycle generally follow the equation of ²⁰⁸Pb/²⁰⁶Pb = −1.157 × ²⁰⁶Pb/²⁰⁷Pb + 3.46 (r² = 0.941). However, Pb isotopes have different mobility in different environmental matrixes. Whereas in the pedosphere, the heavier Pb (²⁰⁸Pb) usually shows stronger mobility relative to the lighter Pb, and is more likely to transfer into soil exchangeable Pb fraction and carbonates phase. The lighter Pb shows stronger transfer ability from soil to cereal grain via root compared to the heavier Pb. However, the cereal grains have lower ²⁰⁶Pb/²⁰⁷Pb and higher ²⁰⁸Pb/²⁰⁶Pb ratios than root and tillage soil, similar to the airborne Pb and anthropogenic Pb, implying that a considerable amount of Pb in cereal grains comes from the atmosphere. The estimate model shows that 16.7–52.6% (average: 33.5%) of Pb in rice grain is the airborne Pb.