NMOC,ozone, and organic aerosol in the southeastern United States, 1999–2007: 1. Spatial and temporal variations of NMOC concentrations and composition in Atlanta,Georgia

Volatile organic compounds (VOCs) are emitted from anthropogenic and natural (biogenic) sources into the atmosphere. Characterizing their ambient mixing ratios or concentrations is a challenge because VOCs comprise hundreds of species, and accurate measurements are difficult. Long-term hourly and daily-resolution data have been collected in the metropolitan area of Atlanta, Georgia, a major city dominated by motor vehicle emissions. A series of observations of daily, speciated C₂–C₁₀ non-methane organic compounds (NMOC) and oxygenated hydrocarbons (OVOC) in mid-town Atlanta (Jefferson Street, JST) are compared with data from three urban-suburban sites and a nearby non-urban site. Annual-average mixing ratios of NMOC and OVOC at JST declined from 1999 through 2007. Downward trends in NMOC, CO, and NO_y corroborate expected emission changes as reflected in emission inventories for Atlanta’s Fulton County. Comparison of the JST NMOC composition with data from roadside and tunnel sampling reveals similarities to motor vehicle dominated samples. The JST annual average VOC-OH reactivities from 1999 to 2007 were relatively constant compared with the decline in annual-average NMOC mixing ratios. Mean reactivity at JST, in terms of concentration*k_OH, was approximately 40% alkenes, 22% aromatics, 16% isoprene and 6% other biogenics, 13% C₇–C₁₀ alkanes and 3% C₂-C₆ alkanes, indicating that biogenic NMOCs are important but not dominant contributors to the urban reactive NMOC mix. In contrast, isoprene constituted ～50% of the VOC-OH reactivities at two non-urban sites. Ratios of 24-hour average CO/benzene, CO/isopentane, and CO/acetylene concentrations indicate that such species are relatively conserved, consistent with their low reactivity. Ratios of more-reactive to less-reactive species show diurnal variability largely consistent with expected emission patterns, transport and mixing of air, and chemical processing.     

Toxicity, dioxin-like activities, and endocrine effects of DDT metabolites—DDA, DDMU, DDMS, and DDCN

Background, aim, and scope  

2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) metabolites, other than those routinely measured [i.e., 2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE) and 2,2-bis(chlorophenyl)-1,1-dichloroethane (DDD)], have recently been detected in elevated concentrations not only in the surface water of Teltow Canal, Berlin, but also in sediment samples from Elbe tributaries (e.g., Mulde and Havel/Spree). This was paralleled by recent reports that multiple other metabolites could emerge from the degradation of parent DDT by naturally occurring organisms or by interaction with some heavy metals. Nevertheless, only very few data on the biological activities of these metabolites are available to date. The objective of this communication is to evaluate, for the first time, the cytotoxicity, dioxin-like activity, and estrogenicity of the least-studied DDT metabolites.     

Aspergillus awamori attenuates ochratoxin A-induced renal and cardiac injuries in rabbits by activating the Nrf2/HO-1 signaling pathway and downregulating IL1β, TNFα, and iNOS gene expressions

Environmental Science and Pollution Research - Ochratoxin A (OTA) is one of the most dangerous and that pollute agricultural products, inducing a variety of toxic effects in humans and animals. The...     

Carbon Monoxide and Sulfur Dioxide Adsorption on— and Desorption from Glass,Plastic, and Metal Tubings

It was planned to install 305 m (1000 ft) of tubing on a television tower to transport ambient air samples from different height levels to pollutant monitoring instruments at ground level. A feasibility study was undertaken to determine the sorption characteristics of sulfur dioxide and carbon monoxide on various conduit materials. Sorption studies were completed on 30.5 m (100 ft) lengths of 1.3 cm (Y2 in) diam tubings of glass, Teflon, tygon, polypropylene, PVC piping, aluminum, and stainless steel. Final tests were completed on 305 m of 1.9 cm (3/4 in) diam stainless steel tubing. The following variables were investigated: tubing diameter, gas concentration, flowrate through the tubing, temperature, humidity, and the effect of sorption with sulfur dioxide and carbon monoxide alone or together. The parameter ranges studied approximated either atmospheric or air sampling conditions. For carbon monoxide, there was no significant difference between the mean inlet and outlet tubing concentrations under the conditions of the study. With sulfur dioxide, there was neither tubing adsorption nor desorption under the experimental parameters studied, except for tygon, PVC, and aluminum. After a conditioning period with sulfur dioxide, tygon, PVC, and aluminum could also be used as air inlet conduits; tygon is not recommended.     

Industrial transformation and shrimp aquaculture in Thailand and Vietnam: pathways to ecological,social, and economic sustainability?

Shrimp aquaculture in Vietnam is in the process of being transformed into a major industry around the intensification of the production system. The experiences of other countries in the region, especially in Thailand where high input production systems dominate, suggests that now is a critical time for intervention to redirect industry into pathways that are more sustainable ecologically, socially, and economically. In Thailand, years of experience with intensified systems and a complex industrial organization has not led to sustainable solutions. The challenge here is for society to regain control and then to redirect the transformation along more efficient and benign pathways. Our analyses suggest that current pathways in both countries are unlikely to lead to a sustainable industry. A complete transformation of the way shrimp are grown, fed, processed, distributed, and regulated is needed.     

A History of the Production and Use of Carbon Tetrachloride,Tetrachloroethylene, Trichloroethylene and 1,1,1-Trichloroethane in the United States: Part 1—Historical Background; Carbon Tetrachloride and Tetrachloroethylene

Carbon tetrachloride (CTC), tetrachloroethylene (PCE), trichloroethylene (TCE) and 1,1,1-trichloroethane (TCA) were four of the most widely used cleaning and degreasing solvents in the United States. These compounds were also used in a wide variety of other applications. The history of the production and use of these four compounds is linked to the development and growth of the United States' synthetic organic chemical industry, and historical events that affected the development and use of chlorinated solvents in general. Part 1 of this article includes a discussion of the historical background common to each of the four solvents, followed by discussion on the history of CTC and PCE. In the early years of the 20th century, CTC became the first of the four solvents to come into widespread use. CTC was used as a replacement for petroleum distillates in the dry-cleaning industry, but was later replaced by PCE. In the 1990s, CTC was phased out under the Montreal Protocol due to its role in stratospheric ozone depletion.     

PCB153 and p,p′-DDE disorder thyroid hormones via thyroglobulin,deiodinase 2, transthyretin,hepatic enzymes and receptors

Polychlorinated biphenyls (PCBs) and DDT are widespread environmental persistent organic pollutants that have various adverse effects on reproduction, development and endocrine function. In order to elucidate effects of PCBs and DDT on thyroid hormone homeostasis, Sprague–Dawley rats were dosed with PCB153 and p,p′-DDE intraperitoneally (ip) for five consecutive days and sacrificed within 24 h after the last dose. Results indicated that after combined exposure to PCB153 and p,p′-DDE, total thyroxine , free thyroxine, total triiodothyronine, and thyroid-stimulating hormone in serum were decreased, whereas free triiodothyronine and thyrotropin-releasing hormone were not affected. Thyroglobulin and transthyretin levels in serum were significantly reduced. mRNA expression of deiodinases 2 (D2) was also suppressed, while D1 and D3 levels were not significantly influenced after combined exposure. PCB153 and p,p′-DDE induced hepatic enzymes, UDPGTs, CYP1A1, CYP2B1, and CYP3A1 mRNA expressions being significantly elevated. Moreover, TRα1, TRβ1, and TRHr expressions in the hypothalamus displayed increasing trends after combined exposure to PCB153 and p,p′-DDE. Taken together, observed results indicate that PCB153 and p,p′-DDE could disorder thyroid hormone homeostasis via thyroglobulin, deiodinase 2, transthyretin, hepatic enzymes, and hormone receptors.     

Temporal and spatial trends of PCBs,DDTs, HCHs,and HCB in Swedish marine biota 1969–2012

In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70–90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg^?1 lipid weight and 5 µg kg^?1 wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms.     

PM2.5, soot and NO2 indoor–outdoor relationships at homes,pre-schools and schools in Stockholm,Sweden

In developed nations people spend about 90% of their time indoors. The relationship between indoor and outdoor air pollution levels is important for the understanding of the health effects of outdoor air pollution. Although other studies describe both the outdoor and indoor atmospheric environment, few excluded a priori major indoor sources, measured the air exchange rate, included more than one micro-environment and included the presence of human activity. PM_2.5, soot, NO₂ and the air exchange rate were measured during winter and summer indoors and outdoors at 18 homes (mostly apartments) of 18 children (6–11-years-old) and also at the six schools and 10 pre-schools that the children attended. The three types of indoor environments were free of environmental tobacco smoke and gas appliances, as the aim was to asses to what extent PM_2.5, soot and NO₂ infiltrate from outdoors to indoors. The median indoor and outdoor PM_2.5 levels were 8.4 μg m^?3 and 9.3 μg m^?3, respectively. The median indoor levels for soot and NO₂ were 0.66 m^?1 × 10^?5 and 10.0 μg m^?3, respectively. The respective outdoor levels were 0.96 m^?1 × 10^?5 and 12.4 μg m^?3. The median indoor/outdoor (I/O) ratios were 0.93, 0.76 and 0.92 for PM_2.5, soot and NO₂, respectively. Their infiltration factors were influenced by the micro-environment, ventilation type and air exchange rate, with aggregated values of 0.25, 0.55 and 0.64, respectively. Indoor and outdoor NO₂ levels were strongly associated (R² = 0.71), followed by soot (R² = 0.50) and PM_2.5 (R² = 0.16). In Stockholm, the three major indoor environments occupied by children offer little protection against combustion-related particles and gases in the outdoor air. Outdoor PM_2.5 seems to infiltrate less, but indoor sources compensate.     

C5–C12 volatile organic compounds at roadside,residential, and background locations in Ankara,Turkey: Temporal and spatial variations and sources

Abstract

Particle emissions of modern diesel engines are of a particular interest because of their negative health effects. The special interest is in nanosized solid particles. The effect of an open channel filter on particle emissions of a modern heavy-duty diesel engine (MAN D2066 LF31, model year 2006) was studied. Here, the authors show that the open channel filter made from metal screen efficiently reduced the number of the smallest particles and, notably, the number and mass concentration of soot particles. The filter used in this study reached 78% particle mass reduction over the European Steady Cycle. Considering the size-segregated number concentration reduction, the collection efficiency was over 95% for particles smaller than 10 nm. The diffusion is the dominant collection mechanism in small particle sizes, thus the collection efficiency decreased as particle size increased, attaining 50% at 100 nm. The overall particle number reduction was 66–99%, and for accumulation-mode particles the number concentration reduction was 62–69%, both depending on the engine load.     

Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin® and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria

The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen, and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH(4)-inhibitors nitroethane (2 mg/mL), 2-nitro-1-propanol (2 mg/mL), lauric acid (5 mg/mL), the commercial product Lauricidin? (5 mg/mL), and a finely ground product of the Hawaiian marine algae, Chaetoceros (10 mg/mL), were compared in pure cultures of Streptococcus agalactia, Enterococcus faecium, Streptococcus bovis, and in a mixed lactic acid rumen bacterial culture. Lauricidin? and lauric acid exhibited the most bactericidal acidity against all bacteria. These results suggest potential animal health benefits from supplementing cattle diets with lauric acid or Lauricidin? to improve the health of the rumen and help prevent shedding of human pathogens.     

Environmental prevalence,fate, impacts,and mitigation of microplastics—a critical review on present understanding and future research scope

Environmental Science and Pollution Research - Microplastics are considered to be ubiquitous and widespread emerging contaminants. They are persistent in the nature and pose considerable harm to...     

Is selenium affecting body condition and reproduction in boreal breeding scaup, scoters, and ring-necked ducks?

Elevated levels of selenium (Se) have been detected in wintering and spring-staging lesser scaup. Here, we compared spring scaup Se and mercury (Hg) levels to those of ring-necked ducks and white-winged scoters, species exhibiting increasing and decreasing boreal populations, respectively. Mercury concentrations were low in all three species. Geometric mean (95%CI) liver Se concentrations were 6.2 (5.5-7.0), 4.6 (4.0-5.4), and 32.6 (28.4-37.3)mg/kg dry weight (dw) in scaup, ringnecks and scoters, respectively. Only scoter livers (66%) were above 33 mg/kgdw Se. Scaup and ringneck Se levels were unrelated to breeding status or lipid and protein levels; breeding scoters and females with greater lipid mass had higher Se than non-breeders. Egg and follicle concentrations in scaup and scoters were normal (mean [95%CI]=2.3 [1.9-2.6] and 2.4 [2.1-2.7]mg/kgdw, respectively). Overall, we found no support for a relationship between selenium and boreal scaup and scoter declines, and discuss current Se threshold concentrations.     

Assessment of cadmium accumulation,toxicity, and tolerance in Brassicaceae and Fabaceae plants—implications for phytoremediation

This study, based on a greenhouse pot culture experiment conducted with 15-day-old rapeseed (Brassica campestris L. cv. Pusa Gold; family Brassicaceae) and moong bean (Vigna radiata L. Wilczek cv. Pusa Ratna; family Fabaceae) plants treated with cadmium (Cd) concentrations (0, 50, and 100 mg kg^?1 soil), investigates their potential for Cd accumulation and tolerance, and dissects the underlying basic physiological/biochemical mechanisms. In both species, plant dry mass decreased, while Cd concentration of both root and shoot increased with increase in soil Cd. Roots harbored a higher amount of Cd (vs. shoot) in B. campestris, while the reverse applied to V. radiata. By comparison, root Cd concentration was higher in B. campestris than in V. radiata. The high Cd concentrations in B. campestris roots and V. radiata shoots led to significant elevation in oxidative indices, as measured in terms of electrolyte leakage, H₂O₂ content, and lipid peroxidation. Both plants displayed differential adaptation strategies to counteract the Cd burden-caused anomalies in their roots and shoots. In B. campestris, increasing Cd burden led to a significantly decreased reduced glutathione (GSH) content but a significant increase in activities of GSH reductase (GR), GSH peroxidase (GPX), and GSH sulfotransferase (GST). However, in V. radiata, increasing Cd burden caused significant increase in GSH content and GR activity, but a significant decline in activities of GPX and GST. Cross talks on Cd burden of tissues and the adapted Cd tolerance strategies against Cd burden-accrued toxicity indicated that B. campestris and V. radiata are good Cd stabilizer and Cd extractor, respectively, wherein a fine tuning among the major components (GR, GPX, GST, GSH) of the GSH redox system helped the plants to counteract differentially the Cd load-induced anomalies in tissues. On the whole, the physiological/biochemical characterization of the B. campestris and V. radiata responses to varying Cd concentrations can be of great help in elaborating the innovative plant-based remediation technologies for metal/metalloid-contaminated sites.     

Study on reaction kinetics and selective precipitation of Cu, Zn, Ni and Sn with H₂S in single-metal and multi-metal systems

Determination of reaction kinetics and selective precipitation of Cu, Zn, Ni and Sn with H(2)S in single-metal and multi-metal systems were studied to develop a process of metal recovery from plating wastewater. As samples, single-metal model wastewaters containing Cu, Sn, Zn or Ni, and multi-metal model wastewater containing Cu-Zn-Ni or Sn-Zn mixtures were used. In both single-metal and multi-metal systems, the pH value was precisely controlled at a value of 1.5 for CuS and SnS precipitation, 4.5 for ZnS precipitation and 6.5-7.0 for NiS precipitation. Subsequently, the sulfidation of Cu, Sn, Zn and Ni was evaluated. It was found that an amount of H(2)S equimolar to a given metal was sufficient to achieve almost complete precipitation of the particular metal. Further, the selectivity of metal precipitation was found to be higher than 95% in the Cu-Zn-Ni multi-metal system and higher than 91% in the Sn-Zn system. It was also found that the sulfidation reaction proceeded in accordance with Higbie's penetration theory and reaction rate constants and mass-transfer coefficients under various experimental conditions were determined. Finally, the reaction rate constants obtained in single-metal and multi-metal systems were found to be almost the same indicating that the precipitation of a particular metal was not significantly affected by the presence of other components.     

A step forward using QuEChERS (Quick,Easy, Cheap,Effective, Rugged,and Safe) based extraction and gas chromatography-tandem mass spectrometry—levels of priority polycyclic aromatic hydrocarbons in wild and commercial mussels

A new and fully validated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction and gas chromatography–tandem mass spectrometry methodology was developed and subsequently implemented for the quantification of 16 polycyclic aromatic hydrocarbons (PAHs) in wild (from Matosinhos Beach, Portugal) and commercial (from Ria de Arousa, Spain) mussels. The method proved to be robust, precise, and accurate, with recoveries ranging from 89.2 to 111.8 %. Total sums of 16 PAHs were 52.91 and 37.58 ng/g of wet weight for wild and commercial specimens, respectively. The three- to four-ring PAHs were the most abundant, and a mixture of petrogenic and pyrolytic sources were suspected to occur in both origin areas. Although the contamination levels were below the European regulated limits, specifically for commercial mussels (this despite wild specimens are also consumed), care should be taken in terms of human health, since we are still not aware of the low-dose versus long-term effects, even more in high-risk population groups.     

Vertical and horizontal distribution,source identification,ecological and toxic risk assessment of heavy metals in sediments of Lake Aygır,Kars, Turkey

Surface and core sediment samples were collected from Lake Ayg?r, Turkey, to determine heavy metal distribution, probable sources and potential ecological and toxic risks for the lake. Heavy metals, total sulfur, total phosphate, total organic carbon, chlorophyll degradation products, and CaCO₃ content were established. The enrichment factor, PLI, potential ecological risk index, and toxic risk index were calculated. Zn was determined to have the highest accumulation in surface sediment, followed by Cr, Pb, and Cd, respectively. Cd was the only element that exceeded the critical value of 40 and posed a moderate potential ecological risk. According to TRI, no ecotoxic risk was found. It is thought that local fossil fuel consumption is responsible for the accumulation of heavy metals since there is a lack of urbanization, industrialization, and agricultural activities around the lake.     

Particulate Matter in California: Part 2—Spatial,Temporal, and Compositional Patterns of PM2.5, PM10–2.5, and PM10

Abstract

Geographic and temporal variations in the concentration and composition of particulate matter (PM) provide important insights into particle sources, atmospheric processes that influence particle formation, and PM management strategies. In the nonurban areas of California, annual-average PM_2.5 and PM₁₀ concentrations range from 3 to 10 [H9262]g/m³ and from 5 to 18 µg/m³, respectively. In the urban areas of California, annual-averages for PM_2.5 range from 7 to 30 [H9262]g/m³, with observed 24-hr peaks reaching levels as high as 160 [H9262]g/m³. Within each air basin, exceedances are a mixture of isolated events as well as periods of elevated PM_2.5 concentrations that are more prolonged and regional in nature. PM_2.5 concentrations are generally highest during the winter months. The exception is the South Coast Air Basin, where fairly high values occur throughout the year. Annual-average PM_2.5 mass, as well as the concentrations of major components, declined from 1988 to 2000. The declines are especially pronounced for the sulfate (SO₄ ^2?) and nitrate (NO₃ ^?) components of PM_2.5 and PM₁₀ and correlate with reductions in ambient levels of oxides of sulfur (SO_x) and oxides of nitrogen (NO_x). Annual averages for PM_10–2.5 and PM₁₀ exhibited similar downwind trends from 1994 to 1999, with a slightly less pronounced decrease in the coarse fraction.     

Stratospheric ozone,global warming,and the principle of unintended consequences—An ongoing science and policy story

Supplemental Materials: Supplemental materials are available for this paper. Go to the publisher's online edition of the Journal of the Air & Waste Management Association.